Manufacturer Code Charts: 82

82-SENSOR TOO COLD TO START COOLDOWN TEST (MTC)





For a complete wiring diagram consult Diagrams/Electrical.


- When Monitored:
When executing the Cooldown Test.

- Set Condition:
If the A/C Heater Control senses that the evaporator temperature is below 18.3°C (65°F) when executing the Cooldown Test.







NOTE: This DTC will display as active if the ignition is not cycled after running the Cooldown Test. Otherwise, it will display as stored until cleared.


Diagnostic Test


1. CHECK FOR ACTIVE DTC 31, 32, 83, OR 84 IN THE A/C HEATER CONTROL
Turn the ignition on.
Actuate the Display DTC function by performing the following:
- Turn the blower control on.
- Press the A/C mode switch down, turn the blower control to off, wait until both LEDs illuminate (approximately 5 seconds) and then release the A/C mode switch.


NOTE: The A/C status indicator displays active DTCs when the EBL status indictor is not illuminated and stored DTCs when the EBL status indicator is illuminated.

Read DTCs from the A/C status indictor.
Does the A/C status indicator display DTC 31, 32, 83, or 84?

Yes


- Diagnose and repair the DTC(s). Run the Cooldown Test again after the repair is complete.


No


- Go To 2




2. ERASE DTCs IN THE A/C HEATER CONTROL
Actuate the Clear DTC function by performing the following:
- Turn the blower control on.
- Press the A/C mode switch down, turn the blower control to off, wait until both LEDs illuminate (approximately 5 seconds) and then release the A/C mode switch.
- When the A/C status indicator begins displaying DTCs, set the Mode switch to the floor position, simultaneously press the A/C mode switch and the EBL mode switch down until both LEDs start flashing (approximately 5 seconds) and then release the mode switches. Stored DTCs will clear from memory in approximately two seconds.

Turn the ignition off.





- Go To 3




3. VERIFY IF DTC 82 SET DUE TO EVAPORATOR TEMPERATURE BEING BELOW 18.3°C (65°F)
CAUTION: The work area ambient temperature and the evaporator temperature must be above 18.3°C (65°F) in order to test A/C system performance.

Start the engine.
Set the Mode switch to the panel position.
Press the A/C mode switch off (status indicator not illuminated/compressor not running).
Turn the blower control to high speed. Allow the blower to run for 5 minutes before proceeding.
Turn the blower control off.
Actuate the Cooldown Test by performing the following:
- Press and hold the A/C mode switch down and then turn the blower motor control to high speed. Continue to hold the A/C mode switch down until the A/C status indicator begins flashing, Then, release the mode switch. While the test is running, the A/C status indicator will flash once per second. If the test passes, the A/C status indicator will stop flashing. If the test fails, the A/C and EBL status indicators will flash alternately. Allow the test to run to completion before proceeding.






- Go To 4




4. CHECK FOR DTCS IN THE A/C HEATER CONTROL
Actuate the Display DTC function by performing the following:
- Turn the blower control on.
- Press the A/C mode switch down, turn the blower control to off, wait until both LEDs illuminate (approximately 5 seconds) and then release the A/C mode switch.


NOTE: The A/C status indicator displays active DTCs when the EBL status indictor is not illuminated and stored DTCs when the EBL status indicator is illuminated.

Read DTCs from the A/C status indictor.
Does the A/C status indicator display DTC 82?

Yes, & No Other DTCs Present


- Go To 5


Yes, & Other DTCs Present


- Diagnose and repair the other DTC(s). Run the Cooldown Test again after the repair is complete.


No, But Other DTCs Present


- Diagnose and repair the DTC(s). Run the Cooldown Test again after the repair is complete.


No, & No Other DTCs Present


- Perform additional testing as necessary.




5. CHECK THE (C121) SENSOR GROUND CIRCUIT FOR HIGH RESISTANCE




NOTE: Ensure that the voltmeter leads are connected for positive polarity and that they meet the terminals in the connector. Also ensure that there is a good terminal to wire connection.

Turn the ignition off.
Back probe the (C121) Sensor Ground circuit between the Evaporator Temperature Sensor harness connector and the A/C Heater Control C2 harness connector.
Turn the ignition on.
Is the voltage below 0.10 volts?

Yes


- Go To 6


No


- Repair the (C121) Sensor Ground circuit for high resistance. Run the Cooldown Test again after the repair is complete.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.




6. CHECK THE (C21) EVAPORATOR TEMPERATURE SENSOR SIGNAL CIRCUIT FOR HIGH RESISTANCE




NOTE: Ensure that the voltmeter leads are connected for positive polarity and that they meet the terminals in the connector. Also ensure that there is a good terminal to wire connection.

Turn the ignition off.
Back probe the (C21) Evaporator Temperature Sensor Signal circuit between the Evaporator Temperature Sensor harness connector and the A/C Heater Control C2 harness connector.
Turn the ignition on.
Is the voltage below 0.10 volts?

Yes


- Replace the A/C Heater Control. Run the Cooldown Test again after the repair is complete.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.


No


- Repair the (C21) Evaporator Temperature Sensor Signal circuit for high resistance. Run the Cooldown Test again after the repair is complete.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.