96 Conti Aircon intermittent failure

[ardisius]

My 96 Conti has lately been deciding intermittently not to run the aircon — and south Georgia summer heat, too:eek:

It doesn't quit while running, just that it often won't start up when starting the car. Then suddenly it comes on after driving for a while. I've checked fuses/relays and they're OK. Seems to be in the Climate Control console in the dash.

It always is running OK when I'm close to an auto aircon shop so haven't been able to get anybody to check it for me.

Has anyone had experience with this kind of problem, please?

Regards

Roy

[Steve Moran]

It sounds like (maybe) the sensor for the Climate Control console that takes the interior ambiant temp could be getting dirty or bad,
I do not know where it is located but it is usually on the dash some where.
You need to clean it with a good quality electrical componant cleaner so it has no residue on it .

I see this is not your first post but I have never talked to you before so I say, Hi and welcome to lincolns online.

[ardisius]

Tks Steve

No, haven't had much need to post — superb limousine doesn't give much trouble :D

What you say sounds logical! Now…can anyone tell me where the sensor is located?????:rolleyes:

[Vector]

It is located to the right of the steering wheel, on the dash, about even with the ignition key location you will see a vent with four slots about 3/4" square. That is the where the sensor intake is located. If you pull the dash off you will see that it is connected to the air system by a flex black tube.

BTW, your problem could also be a failing computer module that is located on the top of the cooling fan shroud.

[ardisius]

Tks "Vector" - "Pull the dash off"??? I haven't tried dismantling the dash yet - I'd love to know how/what to/where to pull/unscrew etc!

I'm going to try cleaning out the sensor first: would vacuum-cleaning be the best way to go?

[98TC-Cartier]

Loose connector on the EATC, or maybe the ignition switch itself.
Does any fuction of the climate control work, ie, fan temp setings etc. or is it just the a/c not working??
Have you done a self test on the EATC when it is non working mode?

[ardisius]

Thanks "98TC-Cartier" - I'm a rank amateur (actually an Aussie import—and we don't have Lincolns in Australia!)

How do I self-test the EATC — and is there anywhere I can download a wiring diagram to find where the connectors for the EATC are?

Tks

Roy

[aristo1963]

Electronic Automatic Temperature Control Unit Self-Test

The EATC self-test will detect concerns in the system control functions and will display diagnostic trouble codes (DTC) in addition to intermittent diagnostic trouble codes for concerns that occur during system operation. The vehicle interior temperature should be between 16-26° C (60-80° F when performing the self-test. If the temperatures are not within the specified ranges, false in-car temperature sensor DTCs will be displayed. Record all DTCs displayed.
If any DTCs appear during the self-test, follow the diagnostics procedure given under ACTION for each DTC given.
If a condition exists but no DTCs appear during the self-test, refer to the Symptom Chart Condition: EATC System Inoperative, Intermittent or Improper Operation.
The self-test can be initiated at any time with any resulting DTCs displayed. Normal operation of the system stops when the self-test is activated.
To enter the self-test, press the OFF and FLOOR buttons simultaneously and then press the AUTOMATIC button within two seconds. The display will show a pulse tracer going around the center of the display window. The test may run as long as 30 seconds.
To exit self-test and retain DTCs, push the blue (cooler) button. The control will exit self-test, retain all diagnostic trouble codes and then turn OFF (display blank).
To exit self-test and clear all diagnostic trouble codes, press Defrost button. The vacuum fluorescent display window will show 888 and all function symbols for one second. Then, the EATC control assembly will turn OFF (display blank) and all DTCs will be cleared.The self-test should be deactivated before powering the system down (system turned OFF). Intermittent DTCs will be deleted after 80 ignition switch ON cycles after the intermittent condition occurs.

[aristo1963]

EATC System On-Board Diagnostic Trouble Code Chart DTC Detected Condition Action 024 Fault in blend door calibration during self test GO to Pinpoint Test B (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#B). 025 Intermittent fault in blend door calibration GO to Pinpoint Test B (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#B). 030 Automatic temperature control sensor shorted GO to Pinpoint Test C (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#C). 031 Automatic temperature control sensor open GO to Pinpoint Test C (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#C). 040 Ambient sensor short GO to Pinpoint Test D (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#D). 041 Ambient sensor open GO to Pinpoint Test D (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#D). 042 Ambient sensor intermittent short GO to Pinpoint Test D (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#D). 043 Ambient sensor intermittent open GO to Pinpoint Test D (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#D). 050 Sunload sensor short GO to Pinpoint Test E (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#E). 052 Sunload Sensor intermittent short GO to Pinpoint Test E (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#E). 115 Intermittent engine coolant temperature signal GO to Pinpoint Test F (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#F)or Pinpoint Test G (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#G). 125 Intermittent vehicle speed signal GO to Pinpoint Test F (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#F)or Pinpoint Test G (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#G). 135 Multiplex Communication Network display dimming signal intermittent GO to Lighting Control Module Diagnostic Section 17-02 (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~leftside=STESH20L.htm&rightside=STESH20R.htm&market=us&lang=en~gen~2col.htm). 155 Multiplex Communication Network English/metric signal intermittent GO to Virtual Image Cluster Diagnostic Section 13-01 (file:///C:/TSO/tsocache/DADSMACHINE_1548/STE~us~en~leftside=STESD10L.htm&rightside=STESD10R.htm&market=us&lang=en~gen~2col.htm).

[ardisius]

Aristo and everyone else!

Very many thanks — I really am getting GREAT help here, and I am so very grateful!

NOW — the "Pinpoint Test B", etc, appear to be links to somewhere, but they don't take me to that "somewhere"! Should they?

Aristo — did you "Copy and Paste" all that great info from somewhere? And is that "somewhere" a link/url I can access?

Roy

[98TC-Cartier]

You can download a service manual from http://www.fordcds.com

[aristo1963]

Pinpoint Tests

PINPOINT TEST A: EATC SYSTEM INOPERATIVE, INTERMITTENT OR IMPROPER OPERATION

A1 PERFORM EATC SELF-TEST


Turn EATC System ON. Press the OFF and FLOOR buttons simultaneously and then press the AUTOMATIC button within two seconds. The test may take as long as 30 seconds. A pulse tracer will circle around the center of the display window during the test. When the self-test is completed, DTCs will be displayed in the display window to list faults found during the self-test. DTCs will also be given for intermittent faults encountered during system operation. Record these DTCs.
To exit self-test and retain DTCs push the blue (cooler) button. To exit self-test and clear all DTCs, press the DEFROST button.Were DTCs other than 888 displayed in the on-board diagnostic window?
Yes No REFER to EATC system for On-Board Diagnostic Trouble Codes Chart (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A11.HTM~gen~ref.HTM#obdtccc3a) . PERFORM the necessary diagnosis and service as required. GO to A2 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A2). A2 CHECK BLOWER MANUAL OVERRIDE LOW SPEED OPERATION


Rotate the blower thumbwheel down to the stop.Does the blower motor go to low speed?
Yes No GO to A3 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A3). GO to Pinpoint Test H (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#H). A3 CHECK BLOWER MANUAL OVERRIDE HIGH SPEED OPERATION


Rotate the blower thumbwheel up to the stop.Does the blower motor go to high speed?
Yes No GO to A4 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A4). GO to Pinpoint Test H (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#H). A4 VERIFY DEFROST OVERRIDE OPERATION


Press the defrost button and check system discharge airflow. Airflow should be from the demister nozzle and duct and the A/C side window demister and hose. Also check to be sure the heater and A/C air inlet duct door is in the outside position.Are these two conditions met?
Yes No GO to A5 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A5). REFER to Pinpoint Test A (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A)in Section 12-00 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~leftside=STESC00L.htm&rightside=STESC00R.htm&market=us&lang=en~gen~2col.htm). A5 VERIFY FLOOR OVERRIDE OPERATION


Press the FLOOR button and check system discharge airflow. Discharge airflow should be from the heater outlet floor duct.Is airflow discharged from the heater outlet floor duct?
Yes No GO to A6 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A6). REFER to Pinpoint Test A (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A)in Section 12-00 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~leftside=STESC00L.htm&rightside=STESC00R.htm&market=us&lang=en~gen~2col.htm). A6 VERIFY VENT OVERRIDE OPERATION


Press the VENT button and check system discharge airflow. Airflow should be from theA/C registers.Is this condition met?
Yes No GO to A7 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A7). REFER to Pinpoint Test A (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A)in Section 12-00 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~leftside=STESC00L.htm&rightside=STESC00R.htm&market=us&lang=en~gen~2col.htm). A7 VERIFY A/C CLUTCH DOES NOT ENGAGE IN VENT MODE


Press the VENT button. VENT should be displayed and the A/C clutch should not engage.Are these two conditions met?
Yes No GO to A8 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A8). REFER to Powertrain Control/Emissions Diagnosis Manual . A8 VERIFY MAX A/C OVERRIDE OPERATION


With the ambient temperature above 5°C (41° F), press the MAX A/C button. Check that the heater and A/C air inlet duct door is in the recirc air position (closed to outside air).Is the heater and A/C air inlet duct door closed to outside air?
Yes No GO to A9 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A9). REFER to Pinpoint Test A (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A)in Section 12-00 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~leftside=STESC00L.htm&rightside=STESC00R.htm&market=us&lang=en~gen~2col.htm). A9 VERIFY MAX A/C OPERATION


Press the MAX A/C button again. MAX A/C should be displayed and the A/C clutch should engage for A/C compressor operation.Are these two conditions met?
Yes No GO to A10 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A10). REFER to Powertrain Control/Emissions Diagnosis Manual . A10 VERIFY AUTOMATIC OPERATION


Press the AUTOMATIC button. The selected temperature and AUTOMATIC should be shown in the display window.Is the display correct and complete?
Yes No Test complete. RESTORE vehicle. REFER to EATC system self test in Pinpoint Test Step A1 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A1)and System On-Board Diagnostic Trouble Code Chart (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A11.HTM~gen~ref.HTM#obdtccc3a) in Inspection and Verification. PINPOINT TEST B: A/C ELECTRONIC DOOR ACTUATOR MOTOR INOPERATIVE, INTERMITTENT OR IMPROPER OPERATION

B1 CHECK DTCs


Perform self-test and check diagnostic trouble codes.Is DTC 024 or 025 displayed?
Yes No GO to B2 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#B2). REFER to EATC system On-Board Diagnostic Trouble Code Chart (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A11.HTM~gen~ref.HTM#obdtccc3a) if other DTCs are displayed. If no DTCs, PERFORM Pinpoint Test A (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A). B2 CHECK ACTUATOR DRIVE


Disconnect both electrical connectors from rear of EATC control assembly. Operate the A/C electronic door actuator motor in both directions using any 12-volt battery. The following pins can be jumped to use the vehicle battery. Make sure the ignition switch is in the RUN position. All pins are located in the C2 harness connector.
Trial 1: Pin C2-24, Circuit 57 (BK) to Pin C2-22, Circuit 249 (DB/LG).
Trial 2: Pin C2-24, Circuit 57 (BK) to Pin C2-21, Circuit 250 (O).Does theA/C electronic door actuator motor drive in both directions?
Yes No GO to B3 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#B3). GO to B6 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#B6).

[aristo1963]

B3 PERFORM SELF-TEST


Reconnect wire harness connectors and perform On-Board Diagnostic to check system operation.Is test successful?
Yes No System OK. RESTORE vehicle. GO to B4 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#B4). B4 CHECK RESISTANCES


Drive the blend door actuator to the full counterclockwise position (MAX heat).
Disconnect both harness connectors from rear of EATC module. Measure resistance between the pins shown below at the control assembly C1 harness connector.
Pin C1-15, Circuit 243 (LG/O) to Pin C1-6, Circuit 776 (O/BK) - 5000-7000 ohms
Pin C1-5, Circuit 351 (BR/W) to Pin C1-6, Circuit 776 (O/BK) - 3500-6000 ohms
Pin C1-5, Circuit 351 (BR/W) to Pin C1-15, Circuit 243 (LG/O) - 250-1500 ohmsAre all resistances within value given?
Yes No GO to B5 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#B5). GO to B6 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#B6). B5 RETEST EATC SYSTEM


Reconnect harness connectors and perform self-test, Pinpoint Test Step A1 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#ppts11).Is test successful?
Yes No System OK. RESTORE vehicle. GO to B1 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#B1). B6 CHECK RESISTANCE


Check vehicle wiring harness and connector resistance as shown below. Disconnect both harness connectors from EATC module and theA/C electronic door actuator motor.

EATC Module Connector A/C Electronic Door Actuator Motor Connector C1 Pin C1-5 Circuit 351 (BR/W) to Pin 3 Circuit 351 (BR/W) Pin C1-15 Circuit 776 (O/BK) to Pin 4 Circuit 776 (O/BK) Pin C1-6 Circuit 243 (LG/O) to Pin 2 Circuit 243 (LG/O) C2 Pin C2-22 Circuit 250 (O) to Pin 5 Circuit 250 (O) Pin C2-21 Circuit 249 (DB/LG) to Pin 1 Circuit 249 (DB/LG) Pin C2-24 Circuit 57 (BK) to Pin 6 57 (BK)
Reconnect all three harness connectors at end of this test.Is there 5 ohms or less on all six wires?
Yes No GO to B8 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#B8). GO to B7 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#B7). B7 RETEST AFTER SERVICING WIRING HARNESS


Service/replace wiring harness. Reconnect and perform Pinpoint Test Step A1 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#ppts11).Is test successful?
Yes No Test complete. GO to B1 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#B1). B8 CHECK ACTUATOR POWER


Turn ignition switch to RUN.
Disconnect harness connector from A/C electronic door actuator motor.
Using a voltmeter, check Circuit 1040 (R/LB) at actuator harness connector Pin 8 for voltage.Is battery voltage present?
Yes No REPLACE A/C electronic door actuator motor. GO to B9 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#B9). SERVICE Circuit 1040 (R/LB) for open. RESTORE vehicle. RETEST system. B9 RETEST AFTER REPLACING A/C ELECTRONIC DOOR ACTUATOR MOTOR


After replacing A/C electronic door actuator motor, perform Pinpoint Test Step A1 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#ppts11).Is test successful?
Yes No Test complete. GO to B1 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#B1). PINPOINT TEST C: IN-CAR AIR TEMPERATURE SENSOR INOPERATIVE

C1 PERFORM SELF-TEST


Turn the ignition switch to RUN.
Press OFF and FLOOR buttons simultaneously and then press AUTOMATIC button within two seconds.
Self-test may run as long as 30 seconds.
After self-test, record all DTCs and any temperature display readings.
Press the blue (Cooler) button to exit self-test.Are DTCs 030 or 031 displayed?
Yes No GO to C2 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#C2). GO to C3 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#C3). C2 CHECK SENSOR RESISTANCE


NOTE: An open sensor will cause the warm air discharge at 18° C (65°F) setting. A shorted sensor will cause cool discharge air at 29°C (85°F) setting.

Disconnect the automatic temperature control sensor.
Using an ohmmeter, measure the resistance across the sensor terminals and compare the readings with the following sensor resistance table:

Approximate Temperature Sensor Resistance Acceptance Range 10-20°C (50-68°F) 58K-37K ohms 20-30°C (68-86°F) 37K-24K ohms 30-40°C (86-104°F) 24K-16K ohmsAre resistance values within the specified limits?
Yes No GO to C3 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#C3). REPLACE automatic temperature control sensor. RESTORE vehicle. RETEST system.

[aristo1963]

C3 CHECK POWER SUPPLY TO EATC MODULE


Partially remove EATC module as outlined.
Turn ignition switch to RUN position.
Turn EATC control to AUTOMATIC.
Using a voltmeter connected to a known good ground, check Pin C2-11 Circuit 298 (P/O) and Pin C2-26, Circuit 1040 (R/LB).Was B+ present?
Yes No GO to C4 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#C4). SERVICE open circuit. RESTORE vehicle. RETEST system. C4 CHECK SYSTEM GROUND


Using an ohmmeter connected to a known good ground, connect second lead to Pin C2-24, Circuit 57 (BK).
Measure resistance.Is resistance 5 ohms or less?
Yes No GO to C5 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#C5). REPLACE EATC module. RESTORE vehicle. RETEST system. C5 CHECK EATC CONTROL MODULE


Start engine.
Press MAX A/C or PNL/FLR button.Did A/C or heater actuate?
Yes No GO to C6 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#C6). REPLACE EATC module. RESTORE vehicle. RETEST system. C6 CHECK ASPIRATOR INSTALLATION


Gain access to automatic temperature control sensor hose and elbow as outlined.
Check for proper installation of automatic temperature control sensor hose and elbow.Is aspirator installed properly and hose connected?
Yes No GO to C7 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#C7). SERVICE automatic temperature control sensor hose and elbow as necessary. RESTORE vehicle. RETEST system. C7 CHECK AUTOMATIC TEMPERATURE CONTROL SENSOR OUTPUT AT EATC MODULE


Turn engine off. Leave ignition switch in RUN position.
Disconnect automatic temperature control sensor.
Using a voltmeter, check Pin C1-17 Circuit 790 (W/O) for voltage.Is voltage between 4.8 to 5.1 volts?
Yes No GO to C8 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#C8). REPLACE EATC module. RESTORE vehicle. RETEST system. C8 CHECK AUTOMATIC TEMPERATURE CONTROL CIRCUIT 790 (W/O)


Turn ignition switch OFF.
Using an ohmmeter, check Circuit 790 (W/O) from EATC module connector Pin C1-17 to automatic temperature control sensor connector.Is there continuity?
Yes No GO to C9 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#C9). SERVICE Circuit 790 (W/O) for open. RESTORE vehicle. RETEST system. C9 CHECK AUTOMATIC TEMPERATURE CONTROL SENSOR RETURN CIRCUIT


Using an ohmmeter, check Circuit 470 (PK/BK) for continuity from EATC module connector Pin C1-2 to automatic temperature control sensor connector.Is there continuity?
Yes No REPLACE automatic temperature control sensor. RESTORE vehicle. RETEST system. SERVICE Circuit 470 (PK/BK) for open. RESTORE vehicle. RETEST system. PINPOINT TEST D: A/C AMBIENT AIR TEMPERATURE SENSOR INOPERATIVE

D1 PERFORM SELF-TEST


Turn the ignition switch to RUN.
Press OFF and FLOOR buttons simultaneously and then press AUTOMATIC button within two seconds.
Self-test may run as long as 30 seconds.
After self-test, record all diagnostic trouble codes and any temperature display readings.
Press the blue (cooler) button to exit self-test.Are DTCs 040, 041, 042 or 043 displayed and is temperature display reading - 40°C (-40°F) or 53° C (128°F)?
Yes No GO to D2 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#D2). GO to D3 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#D3). D2 CHECK SENSOR RESISTANCE


NOTE: An open sensor will cause the outside temperature display to read -40° C or -40°F. A shorted sensor will cause the outside temperature display to read 53°C (128° F).

Perform self-test. Exit On-Board Diagnostic using the defrost button to reset the outside temperature display.
Disconnect the A/C ambient air temperature sensor and bracket.
Using an ohmmeter, measure the resistance across the two sensor terminals and compare the reading with the following sensor resistance table:

Approximate Temperature Sensor Resistance Acceptance Range 10-20°C (50-68°F) 58K-37K ohms 20-30°C (68-86°F) 37K-24K ohms 30-40°C (86-104°F) 24K-16K ohmsAre resistance values within the specified limits?
Yes No GO to D3 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#D3). REPLACE A/C ambient air temperature sensor and bracket. RESTORE vehicle. RETEST system.

[aristo1963]

D3 CHECK CIRCUIT 788 (R/O) AT A/C AMBIENT AIR TEMPERATURE SENSOR


Turn ignition switch to the RUN position.
Set EATC module to AUTO position.
Disconnect A/C ambient air temperature sensor and bracket.
Using voltmeter, check between Circuit 788 (R/O) and Circuit 470 (PK/BK) for voltage at sensor connector.Is voltage between 4.7-5.1 volts?
Yes No GO to D6 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#D6). GO to D4 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#D4). D4 CHECK CIRCUIT 788 (R/O) AT EATC MODULE


Using voltmeter, check between EATC module connector Pin C1-1, Circuit 788 (R/O) and Pin C1-2, Circuit 470 (PK/BK) for voltage.Is voltage between 4.7-5.1 volts?
Yes No GO to D5 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#D5). REPLACE EATC module. RESTORE vehicle. RETEST system. D5 CHECK CIRCUIT 788 (R/O) FOR OPEN


Turn ignition switch to the OFF position.
Using a jumper connected to a known good ground, connect other end to Circuit 788 (R/O) at sensor connector.
Using an ohmmeter connected to a known good ground, connect second lead to Pin C1-1 Circuit 788 (R/O) at EATC module connector.
Measure resistance.Is resistance 5 ohms or less?
Yes No GO to D6 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#D6). SERVICE Circuit 788 (R/O) for open. RESTORE vehicle. RETEST system. D6 CHECK CIRCUIT 470 (PK/BK)


Connect jumper to Circuit 470 (PK/BK) at sensor connector.
Using an ohmmeter connected to a known good ground, connect second lead to Pin C1-2 Circuit 470 (PK/BK) at module connector.
Measure resistance.Is resistance 5 ohms or less?
Yes No REPLACE A/C ambient air temperature sensor and bracket. RESTORE vehicle. RETEST system. SERVICE Circuit 470 (PK/BK) for open. RESTORE vehicle. RETEST system. PINPOINT TEST E: A/C SUNLOAD SENSOR INOPERATIVE

E1 PERFORM SELF-TEST


Turn the ignition switch to RUN.
Press OFF and FLOOR buttons simultaneously and then press AUTOMATIC button within two seconds.
Self-test may run as long as 30 seconds.
After self-test, record all DTCs.
Press the blue (cooler) button to exit self-test.Is DTC 050, sunload sensor shorted, displayed?
Yes No GO to E3 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#E3). GO to E2 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#E2). E2 CHECK FOR INTERMITTENT SHORT CIRCUIT

Upon completion of On-Board Diagnostic in E1, was DTC 052 displayed?
Yes No GO to E6 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#E6). GO to E4 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#E4). E3 CHECK SUNLOAD SENSOR RESISTANCE


Disconnect battery ground cable.
Disconnect sunload sensor wire harness connector.
Using an ohmmeter, check the resistance across the two sensor connectors.
NOTE: The A/C sunload sensor (19E663) is a photovoltaic cell and should have some unspecified resistance across the terminals depending on the light available to the sensor. The only test that can be performed without specialized equipment is for a short. If the resistance across the sensor terminals is zero ohms, the sensor is shorted and should be replaced.

Is there zero resistance?
Yes No REPLACE shorted A/C sunload sensor. RESTORE vehicle. GO to E1 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#E1). GO to E4 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#E4). E4 CHECK CIRCUIT 468 (BR) AT SENSOR CONNECTOR


Turn ignition switch to the RUN position.
Turn EATC module to MAX A/C position.
Partially remove EATC module as outlined.
Gain access to the A/C sunload sensor as outlined. Disconnect A/C sunload sensor.
Using voltmeter, check Circuit 468 (BR) for voltage at A/C sunload sensor connector.Is voltage between 4.7-5.1 volts?
Yes No GO to E7 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#E7). GO to E5 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#E5). E5 CHECK CIRCUIT 468 (BR) FOR SHORT TO GROUND


Disconnect the EATC module connector.
Using an ohmmeter connected to good ground, connect other lead to Pin 16, Circuit 468 (BR) of the EATC module connector.Is resistance less than 10 K ohms?
Yes No SERVICE Circuit 468 (BR) for short. RETEST system. GO to E6 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#E6). E6 CHECK CIRCUIT 468 (BR) FOR OPEN


Using an ohmmeter, connect one lead to Pin 16, Circuit 468 (BR) of the EATC module connector and the other lead to Circuit 468 (BR) of the sunload sensor connector.Is resistance 5 ohms or less?
Yes No REPLACE EATC module. RETEST system. SERVICE Circuit 468 (BR) for open. RETEST system. E7 CHECK CIRCUIT 470 (PK/BK) FOR OPEN


Turn the ignition switch to the OFF position.
Using an ohmmeter, connect one lead to Pin 2, Circuit 470 (PK/BK) of the EATC module connector and other lead to Circuit 470 (PK/BK) at the sunload sensor connector.Is resistance 5 ohms or less?
Yes No GO to E8 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#E8). SERVICE Circuit 470 (PK/BK) for open. RETEST system. E8 CHECK CIRCUIT 470 (PK/BK) FOR SHORT TO GROUND


Using an ohmmeter connected to good ground, connect other lead to Pin 2, Circuit 470 (PK/BK) of the EATC module connector.Is resistance less than 10 K ohms?
Yes No SERVICE Circuit 470 (PK/BK) for short. RETEST system. REPLACE EATC module. RETEST system.

[aristo1963]

PINPOINT TEST F: INTERMITTENT VEHICLE MODULE DATA LINK SIGNAL— DIAGNOSTIC TROUBLE CODE 115 OR 125

F1 CHECK POWERTRAIN CONTROL MODULE DIAGNOSTICS


Perform Diagnostic Routines for Powertrain Control Module. Refer to Powertrain Control/Emissions Diagnosis Manual .Do the PCM diagnostics indicate a malfunction of the engine coolant sensor, or vehicle speed signal?
Yes No SERVICE as directed and again PERFORM Pinpoint Test Step A1. PERFORM a continuity test on the multiplex communication network circuits 914 (T/O) and 915 (PK/LB) while wiggling the wires. SERVICE as necessary. PINPOINT TEST G: INTERMITTENT VEHICLE MODULE DATA LINK SIGNAL— DIAGNOSTIC TROUBLE CODES 115 AND 125 SIMULTANEOUSLY

G1 CHECK POWERTRAIN CONTROL MODULE (PCM) DIAGNOSTICS


Perform Diagnostic Routines for Powertrain Control Module. Refer to Powertrain Control/Emissions Diagnosis Manual .Are all the powertrain components functioning properly?
Yes No GO to G2 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#G2). GO to Section 18-04 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~leftside=STESI40L.htm&rightside=STESI40R.htm&market=us&lang=en~gen~2col.htm). G2 CHECK CONTINUITY OF VEHICLE MULTIPLEX COMMUNICATION NETWORK WIRES


Check Circuits 914 (T/O) and 915 (PK/LB) for an open circuit between the EATC control module and thepowertrain control module.Are either or both circuits open?
Yes No GO to Section 18-04 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~leftside=STESI40L.htm&rightside=STESI40R.htm&market=us&lang=en~gen~2col.htm). GO to G3 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#G3). G3 CHECK CIRCUITS FOR AN INTERMITTENT OPEN


Check Circuits 914 (T/O) and 915 (PK/LB) for an intermittent open circuit by wiggling each wire at each connector while checking for continuity.Does an intermittent open condition exist?
Yes No SERVICE as necessary. GO to G4 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#G4). CHECK each harness electrical connector for a tight connection; then PERFORM EATC Self Test, Pinpoint Test A (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#A). G4 CHECK INTERMITTENT EATC CONNECTION


Check for EATC Diagnostic Trouble Code 135 or 155.Did code set?
Yes No GO to Section 18-04 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~leftside=STESI40L.htm&rightside=STESI40R.htm&market=us&lang=en~gen~2col.htm). RESTORE vehicle. RETEST system. PINPOINT TEST H: EATC HEATER BLOWER MOTOR DOES NOT RUN

H1 CHECK FUSE


Check power distribution box fuse 1 (40A) to determine if it is good.Is fuse good?
Yes No GO to H4 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#H4). GO to H2 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#H2). H2 CHECK CIRCUIT


Turn ignition switch OFF. Disconnect connector C1 from A/C blower motor speed control. Replace power distribution box fuse 1 (40A) and turn ignition switch to RUN. Measure voltage across Pins 1 and 4 of connector C1.Is voltage greater than 9 volts?


file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=M4954B.gif~gen~ref.gif



Pin Number Circuit Circuit Function C1-1 181 (BR/O) Power—HOT IN RUN C1-2 184 (T/O) Input From EATC Module C1-3 — Not Used C1-4 57 (BK) Ground C1-5 — Not Used C2-1 515 (BK) Blower Motor C2-2 515 (O) Blower Motor
Yes No GO to H3 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#H3). CHECK Circuit 181 (BR/O) and Circuit 57 (BK) between ignition, blower motor relay and A/C blower motor speed control for high resistance and/or an open circuit. Make repairs as required. H3 CHECK BLOWER SPEED CONTROLLER


Turn ignition switch OFF. Connect connector C1 to A/C blower motor speed control. Turn ignition switch to RUN and rotate blower thumbwheel to HI.Does fuse blow?
Yes No CHECK Circuit 515 (O) for short. If not shorted then REPLACE the A/C blower motor speed control. GO to H4 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#H4). H4 CHECK WIRING


Turn ignition switch OFF. Remove speed signal wire (Circuit 184 (T/O) from blower motor speed control harness connector. Turn ignition switch to RUN with EATC system on AUTOMATIC, blower on HI.Does blower motor run at high speed?
Yes No GO to H5 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#H5). GO to H6 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#H6). H5 CHECK FOR OPEN CIRCUIT


Check Circuit 184 (T/O) for an open circuit. Wiggle wire while testing.Is wire OK?
Yes No REPLACE EATC module. SERVICE as necessary.

[aristo1963]

H6 CHECK VOLTAGE


With Circuit 184 (T/O) still disconnected, turn ignition switch to RUN and set control blower thumbwheel to HI. Check voltage across blower motor speed control harness connector C2.Is voltage greater than 0.5 volt?
Yes No CHECK blower motor. REPLACE if required. REPLACE A/C blower motor speed control. PINPOINT TEST J: EATC HEATER BLOWER MOTOR OPERATES IN HIGH IN ALL BLOWER WHEEL POSITIONS

J1 CHECK BLOWER OPERATION


Turn ignition switch OFF. Disconnect harness connector C2 from the rear of the EATC module. Ground connector Pin 23, Circuit 184 (T/O). Then, turn ignition switch to RUN. Blower motor should not operate.Does the blower motor operate?
Yes No GO to J2 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#J2). REPLACE EATC module. J2 CHECK BLOWER SPEED CONTROLLER


Turn ignition switch to OFF. Reconnect harness connector to EATC module. Disconnect Circuit 184 (T/O) from A/C blower motor speed control connector Pin C1-2 and reconnect connector to A/C blower motor speed control. Then, jump Pin C1-4 (ground) to Pin C1-2 of A/C blower motor speed control. Turn ignition switch to RUN. Blower motor should not operate.Does blower motor operate?


file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=M4954B.gif~gen~ref.gif



Pin Number Circuit Circuit Function C1-1 181 (BR/O) Power—HOT IN RUN C1-2 184 (T/O) Input From EATC Module C1-3 — Not Used C1-4 57 (BK) Ground C1-5 — Not Used C2-1 515 (BK) Blower Motor C2-2 515 (O) Blower Motor
Yes No REPLACE A/C blower motor speed control. SERVICE Circuit 184 (T/O) for open. PINPOINT TEST K: EATC HEATER BLOWER MOTOR DOES NOT OPERATE AT LOWER SPEEDS

K1 CHECK VOLTAGE STABILITY


Turn ignition switch to OFF. Disconnect connector C1 from the A/C blower motor speed control. Connect a 10K ohm resistor between Pin C1-1, Circuit 181 (BR/O) and Pin C1-2, Circuit 184 (T/O). Turn ignition switch to RUN and set the blower thumbwheel halfway between LO and HI. Measure the DC voltage across the resistor (range is 0-5 volt). Voltage reading should not be erratic.Is the voltage reading erratic (fluctuating)?


file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=M4954B.gif~gen~ref.gif



Pin Number Circuit Circuit Function C1-1 181 (BR/O) Power—HOT IN RUN C1-2 184 (T/O) Input From EATC Module C1-3 — Not Used C1-4 57 (BK) Ground C1-5 — Not Used C2-1 515 (BK) Blower Motor C2-2 515 (O) Blower Motor
Yes No REPLACE EATC module. GO to K2 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#K2). K2 CHECK VOLTAGE


Continuing with conditions in Step 1, rotate the blower thumbwheel toward HI while observing the voltage reading. Then, rotate the blower thumbwheel toward LO and observe the voltage reading.Does the voltage reading change, increase as thumbwheel is rotated toward HI and decrease when rotated toward LO?
Yes No REPLACE A/C blower motor speed control. REPLACE EATC module. PINPOINT TEST L: EATC HEATER BLOWER MOTOR DOES NOT OPERATE AT HIGH SPEED

[aristo1963]

L1 CHECK BLOWER MOTOR OPERATION


Start engine, select MAX A/C and position the blower thumbwheel to a position midway between LO and HI. Verify that the blower motor operates. Then, rotate the blower thumbwheel to HI and check to see if the blower speed responds to the thumbwheel movement.Does the blower speed increase with movement of the thumbwheel toward HI?
Yes No REFER to self-test, Pinpoint Test Step A1. GO to L2 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#L2). L2 CHECK INPUT VOLTAGE


With ignition switch OFF, disconnect harness connector C1 from the A/C blower motor speed control.
Start engine, select MAX A/C and rotate the blower thumbwheel to HI. Check voltage between Pins C1-2, Circuit 184 (T/O) and C1-4, Circuit 57 (B/K). Voltage should be 10 or more volts.

file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=M4954B.gif~gen~ref.gif



Pin Number Circuit Circuit Function C1-1 181 (BR/O) Power—HOT IN RUN C1-2 184 (T/O) Input From EATC Module C1-3 — Not Used C1-4 57 (BK) Ground C1-5 — Not Used C2-1 515 (BK) Blower Motor C2-2 515 (O) Blower MotorIs voltage 10 volts or more?
Yes No REPLACE A/C blower motor speed control. GO to L3 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#L3). L3 CHECK VOLTAGE


Reconnect harness connector to A/C blower motor speed control.
Start engine, select MAX A/C and rotate blower thumbwheel to HI. Measure voltage on Circuit 184 (T/O) between Pin C2-23 of the EATC module and ground. Voltage on Circuit 184 (T/O) must indicate 10 or more volts when the blower thumbwheel is rotated to the stop at HI.Is voltage 10 volts or greater?
Yes No SERVICE Circuit 184 (T/O). REPLACE EATC module. PINPOINT TEST M: COLD ENGINE BLOWER CONTROL DIAGNOSIS— NO DTC

M1 CHECK COLD ENGINE BLOWER MOTOR OPERATION


Make sure engine coolant is below 49°C (120° F) (cold engine) and control set at 32°C (90° F) AUTOMATIC.Doesblower motor stay off before 3-1/2 minutes have elapsed since engine start-up?
Yes No GO to M2 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#M2). GO to M6 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#M6). M2 CHECK WARM ENGINE BLOWER MOTOR OPERATION


Allow engine to operate until blower motor speed increases from low blower. Check amount of time required for blower motor speed to increase.Does blower motor speed increase before 3-1/2 minutes have elapsed?
Yes No Cold engine lock out functioning properly. GO to self-test, Pinpoint Test Step A-1. GO to M3 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#M3). M3 PERFORM SELF-TEST


Press OFF and FLOOR buttons simultaneously and then press AUTOMATIC button within two seconds. Self-test may run as long as 30 seconds. After self-test, DTCs will be displayed. Record all DTCs and press the blue (Cooler) button.Was DTC 115 displayed?
Yes No GO to M5 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#M5). GO to M4 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#M4). M4 CHECK BLOWER MOTOR OPERATION


Select MAX A/C, turn ignition switch to RUN and rotate blower thumbwheel to HI.Does blower motor operate?
Yes No REPLACE EATC module. RESTORE vehicle. RETEST system. GO to H1 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#H1). M5 CHECK ENGINE COOLANT LEVEL


Check engine coolant level.Is engine coolant level low?
Yes No ADD recommended coolant mixture to bring coolant to specified level. REFER to Section 03-03 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~leftside=STES330L.htm&rightside=STES330R.htm&market=us&lang=en~gen~2col.htm). RETEST system for proper operation. GO to M6 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#M6).

[aristo1963]

M6 CHECK ENGINE COOLANT TEMPERATURE SIGNAL


Perform powertrain control module On-Board diagnostics to check for correct operation of engine coolant temperature sensor. Refer to Powertrain Control/Emissions Diagnosis Manual .Do PCM diagnostics indicate an engine coolant temperature sensor fault?
Yes No SERVICE as necessary. GO to M1 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#M1). GO to M7 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#M7). M7 CHECK COLD ENGINE LOCK-OUT SIGNAL CIRCUITS FOR OPEN WIRE


Check wire Circuits 914 (T/O) and 915 (PK/LB) for an open in multiplex communication network.Are either or both circuits open?
Yes No GO to Section 18-04 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~leftside=STESI40L.htm&rightside=STESI40R.htm&market=us&lang=en~gen~2col.htm). GO to M8 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#M8). M8 CHECK COLD ENGINE LOCK-OUT CIRCUITS FOR AN INTERMITTENT OPEN


Wiggle each wire at each connector to check for an intermittent open.Does an intermittent open condition exist?
Yes No GO to Section 18-04 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~leftside=STESI40L.htm&rightside=STESI40R.htm&market=us&lang=en~gen~2col.htm). REPLACE EATC assembly. RESTORE vehicle. RETEST system. PINPOINT TEST N: CONTROL ASSEMBLY/VFD DOES NOT LIGHT UP— HEATER BLOWER MOTOR OFF

N1 CHECK ILLUMINATION SUPPLY TO EATC MODULE


Turn headlamp switch to the park lamp or headlamp position.
Set headlamp dimmer sensor control to full-on without turning the dome lamp on.
Partially remove EATC module as outlined.
Using a test lamp, check Circuit 19 (LB/R) for voltage.Did test lamp illuminate?
Yes No GO to N2 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#N2). SERVICE Circuit 19 (LB/R) for open circuit. RESTORE vehicle. RETEST system. N2 CHECK EATC SYSTEM GROUND


Using an ohmmeter connected to a known good ground, connect second lead to EATC module connector Pin C2-24, Circuit 57 (BK).
Measure resistance.Is resistance 5 ohms or less?
Yes No REPLACE EATC module. RESTORE vehicle. RETEST system. SERVICE Circuit 57 (BK) for open circuit. RESTORE vehicle. RETEST system. PINPOINT TEST P: TEMPERATURE DISPLAY WILL NOT SWITCH BETWEEN CELSIUS AND FAHRENHEIT

P1 CHECK EATC °C TO °F DISPLAY


With EATC system on AUTOMATIC, press MAX A/C and defrost buttons simultaneously for at least 0.75 second.Did display change between °C and °F?
Yes No GO to P2 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#P2). REPLACE EATC assembly. RESTORE vehicle. RETEST system. P2 CHECK ENGLISH/METRIC FUNCTION


Press ENGLISH/METRIC button on virtual image cluster.Did EATC display change between °C and ° F?
Yes No RESTORE vehicle. RETEST system. GO to Section 18-04 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~leftside=STESI40L.htm&rightside=STESI40R.htm&market=us&lang=en~gen~2col.htm). PINPOINT TEST Q: TEMPERATURE SET POINT DOES NOT REPEAT AFTER TURNING IGNITION SWITCH OFF

Q1 CHECK MEMORY SUPPLY TO EATC MODULE


With ignition switch in the OFF position, partially remove EATC control module as outlined.
Using a voltmeter, check EATC module Pin C2-12, Circuit 1111 (P/O) for voltage.Is battery voltage present?
Yes No REPLACE EATC module. RESTORE vehicle. RETEST system. GO to Q2 (file:///C:/TSO/tsocache/DADSMACHINE_2804/STE~us~en~file=STEC3A13.HTM~gen~ref.HTM#Q2). Q2 CHECK CIRCUIT 1111 (P/O) SUPPLY


Remove memory fuse (10A) at fuse junction panel.
Using an ohmmeter, check EATC module connector Pin C2-12, Circuit 1111 (P/O) to output side of memory fuse (10A) cavity for continuity.Is resistance 5 ohms or less?
Yes No REPLACE EATC module. RESTORE vehicle. RETEST system. SERVICE Circuit 1111 (P/O) for open. RESTORE vehicle. RETEST system.

[aristo1963]

dagnabit i hope your happy my cut and paste finger is crampin:p

[ardisius]

Wowee!

Couldn't have wished for better help! As they say is Aussie, "Ya blood's worth bottling!"

Very many thanks indeed! So far the Self-test is just returning me the 888etc, but that's when it's working OK. I'll do the self-test again the moment it plays up again and refer to my "Aristo-clopedia"

:gears:

Roy

[GlassesRx]

All I have to say to Aristo..."We're not worthy".

[ardisius]

End note:

No joy with self-testing, but spoke to a local mechanic and he advised a common (?) problem is that the solenoid plate on the compressor wears down and gets too far away for the magnet in the pull-in solenoid to grab. Says usually a tap on the compressor with a hammer or wrench will free it. Of course, the compressor is right down under, and on a hot day (when it quits!) that's not too bright a prospect — particularly when I have my good gear on!

Thanks again to all.

Roy

[ekooke]

Has the system low side pressure been checked? It requires a minimum of 45 psi at the low side port to close the LPS that sends current to the compressor clutch.

[ardisius]

Developments...

Battery (almost new) had been running down and wondered why! Finally discovered the alternator was failing to give consistent output — cost me $400 to get it replaced as I was out of town when it finally went down and had to get it fixed to get home! The mechanic had me where he wanted me: pay or walk home!

Anyway, after replacing the alternator, and once the battery had fully charged up again, the air problem rarely occurs. When it does, it is always after I start up, and shift into drive before the air suspension has finished pumping up. (I don't move off before the suspension builds up, just engaging Drive). If I remember not to do that, all is fine!

Thanks to all :)

[LSRX101]

Developments...

Battery (almost new) had been running down and wondered why! Finally discovered the alternator was failing to give consistent output — cost me $400 to get it replaced as I was out of town when it finally went down and had to get it fixed to get home! The mechanic had me where he wanted me: pay or walk home!

Anyway, after replacing the alternator, and once the battery had fully charged up again, the air problem rarely occurs. When it does, it is always after I start up, and shift into drive before the air suspension has finished pumping up. (I don't move off before the suspension builds up, just engaging Drive). If I remember not to do that, all is fine!

Thanks to all :)

It's a simple matter to adjust the air gap on the clutch plate. Just remove the center bolt, slide the plate off and remove one of the shims on the compressor shaft.