Diagnostic Procedure
COOLDOWN TEST TOO COLD TO START - MTC SYMPTOM CHART
| TEST | ACTION | APPLICABILITY |
|---|---|---|
| 1 |
CAUTION:
The evaporator temperature must be above 12.7°C (55°F) and the work area ambient temperature must be above 21.1°C (70°F) to test A/C system operation. Start the engine.Turn the A/C off.Turn the Blower on high. Allow the blower to run for 5 minutes to ensure that the Evaporator Temperature Sensor temperature is above 12.7°C (55°F).With the DRBIII®, actuate the AC Cooldown Test.Does the DRBIII® display: Cooldown Test Too Cold To Start?Yes --> Go To 2No --> Perform additional testing as necessary.Perform BODY VERIFICATION TEST - VER 1
. |
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| 2 |
CAUTION:
The evaporator temperature must be above 12.7°C (55°F) and the work area ambient temperature must be above 21.1°C (70°F) to test A/C system operation. Turn the ignition on.With the DRBIII®, read Active HVAC DTCs.Does the DRBIII® display any DTCs?Yes --> Return to the Heating & A/C symptom list and choose the symptom(s). After the repair is complete, erase the DTC(s), and run the AC Cooldown Test again.Perform BODY VERIFICATION TEST - VER 1
.No --> Go To 3 |
All |
| 3 |
CAUTION:
The evaporator temperature must be above 12.7°C (55°F) and the work area ambient temperature must be above 21.1°C (70°F) to test A/C system operation. Turn the ignition on.With the DRBIII®, read Powertrain Control Module (PCM) DTCs.Does the DRBIII® display any DTCs?Yes --> Refer to POWERTRAIN DIAGNOSTIC PROCEDURES
for the related symptom(s). After the repair is complete, erase the DTC(s), and run the AC Cooldown Test again.Perform BODY VERIFICATION TEST - VER 1
.No --> Go To 4 |
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| 4 | Turn the ignition off. Disconnect the A/C Heater Control C1 harness connector. Measure the resistance between the Evaporator Temperature Sensor Signal circuit and the Sensor Ground circuit. The approximate circuit resistance should be: 1,468 ohms @ 40°C (104°F). 1,800 ohms @ 35°C (95°F). 2,221 ohms @ 30°C (86°F). 2,757 ohms @ 25°C (77°F). 3,443 ohms @ 20°C (68°F). 4,330 ohms @ 15°C (59°F). 5,485 ohms @ 10°C (50°F). 7,354 ohms @ 4°C (39°F). 8,130 ohms @ 2°C (36°F). Is the resistance within the specifications? Yes --> Replace the A/C Heater Control in accordance with the Service Information. Perform BODY VERIFICATION TEST - VER 1 . No --> Check the related ckts & connectors for conditions that would cause a high resistance in the ckts. Repair as necessary. If Ok, replace the Evap Temp Sensor in accordance with the Service Information. After repair is complete, run the Cooldown Test again. Perform BODY VERIFICATION TEST - VER 1 . |
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