DTC Troubleshooting: H

DTC indicator H:  A Short in the Evaporator Temperature Sensor Circuit

1.Clear the DTC by turning the ignition switch OFF, and then ON (II).

2.Operate the climate control system in several modes.

3.Check for DTCs using the self-diagnostic.

Is DTC H indicated?


YES - Go to 4.


NO - Intermittent failure.n


4.Turn the ignition switch OFF.

5.Test the evaporator temperature sensor.

Does the evaporator temperature sensor test OK?


YES - Go to 6.


NO - Replace the  evaporator temperature sensor.n


6.Disconnect climate control unit 28P connector (with ETCS) or PCM connector E (31P) (without ETCS).

7.Check for continuity between the No. 21 terminal of the climate control unit 28P connector (with ETCS) or No. 12 terminal of the PCM connector E (31P) (without ETCS) and body ground.

With ETCS 

Without ETCS 

Is there continuity?


YES - Repair short to body ground in the wire between the climate control unit (with ETCS) or PCM (without ETCS) and the evaporator temperature sensor.n


NO -

  • With ETCS: Go to 8.
  • Without ETCS: Go to 9.

8.Check for continuity between the No. 21 terminal and the No. 18 terminal of climate control unit 28P connector.

 

Is there continuity?


YES - Repair short in the wires between the climate control unit and the evaporator temperature sensor.n


NO - Substitute a known-good climate control unit, and recheck. If the symptom/indication goes away, replace the original  climate control unit.n

9.Check for continuity between the No. 22 terminal of climate control unit 28P connector and the No. 4 terminal of the PCM connector E (31P).

 

Is there continuity?


YES - Repair short in the wires between the climate control unit, PCM and the  evaporator temperature sensor.n


NO - Substitute a known-good climate control unit or PCM, and recheck. If the symptom/indication goes away, replace the original  climate control unit or  PCM.n