Manufacturer Code Charts: 9

HVAC DTC Troubleshooting: 9

DTC indicator 9:

A Short in the Evaporator Temperature Sensor Circuit

1. Turn the ignition switch to LOCK (0), and then to ON (II).

2. Do the self-diagnostic function with the HVAC control unit How To Troubleshoot The Heating And A/C Systems (Without Climate Control).

3. Check for DTCs.

Is DTC 9 indicated?

YES -

Go to step 4.

NO -

Intermittent failure. Check for loose wires or poor connections on the evaporator temperature sensor circuit

4. Turn the ignition switch to LOCK (0).

5. Remove the evaporator temperature sensor Service and Repair and test it Evaporator Temperature Sensor Test.

Is the evaporator temperature sensor OK?

YES -

Go to step 6.

NO -

Replace the evaporator temperature sensor Service and Repair.�

6. Disconnect the HVAC control unit 28P connector.

7. Check for continuity between body ground and the HVAC control unit 28P connector terminal No. 9.





Is there continuity?

YES -

Repair a short to body ground in the wire between the HVAC control unit and the evaporator temperature sensor.�

NO -

Go to step 8.

8. Check for continuity between the HVAC control unit 28P connector terminals No. 9 and No. 19.





Is there continuity?

YES -

Repair a short in the wires between the HVAC control unit and the evaporator temperature sensor.�

NO -

Substitute a known-good HVAC control unit, and recheck. If the symptom/indication goes away, replace the original HVAC control unit HVAC Control Unit Removal/Installation (Without Climate Control).�