Evaporator Temperature Sensor Circuit Open (Active)

When Monitored:

With ignition on.

Set Condition:

This DTC will set if the A/C-Heater Control Module sees voltage more than 4.9 volts on the Evaporator Temperature Sensor Signal circuit.

Possible Causes:

Evaporator Temperature Sensor Signal circuit shorted high.
Evaporator Temperature Sensor.
Evaporator Temperature Sensor Signal circuit open.
Sensor Ground circuit open.
A/C-Heater Control Module.

CAUTION: Always turn ignition off before disconnecting or connecting any control module connector. Failure to do so could result in damage to control module.

NOTE: Ensure vehicle being tested has a fully charged battery. If it does not, false DTCs or error messages may occur.

NOTE: For component location, see appropriate illustration under COMPONENT LOCATIONS . For terminal identification, see appropriate illustration under CONNECTOR IDENTIFICATION . For circuit and wire color identification, see WIRING DIAGRAMS . For component removal and installation procedures, see appropriate component under REMOVAL & INSTALLATION .

Testing:

Turn ignition off. Disconnect the A/C-Heater Control Module C1 and C2 harness connectors. Turn ignition on. Measure voltage between the A/C-Heater Control Module C1 harness connector terminal No. 16 and A/C-Heater Control Module C2 harness connector terminal No. 1. Is there any voltage present? If yes, repair the Evaporator Temperature Sensor Signal circuit for a short to voltage. Perform BODY VERIFICATION TEST under VERIFICATION TESTS. If no, go to next step.
Turn ignition off. Reconnect the A/C-Heater Control Module harness connectors. Disconnect the Evaporator Temperature Sensor harness connector. Connect a jumper wire across the Evaporator Temperature Sensor harness connector. Turn ignition on. Using the DRBIII(R), select SENSOR DISPLAY, then read the Evaporator Temperature Sensor voltage. Is voltage less than 0.1 volt? If yes, replace Evaporator Temperature Sensor. Perform BODY VERIFICATION TEST under VERIFICATION TESTS. If no, go to next step.
Turn the ignition off. Disconnect the A/C-Heater Control Module C1 harness connector. Measure resistance between the A/C-Heater Control Module C1 harness connector terminal No. 16 and the Evaporator Temperature Sensor harness connector terminal No. 1. Is resistance less than 5.0 ohms? If yes, go to next step. If no, repair open in the Evaporator Temperature Sensor Signal circuit. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.
Reconnect A/C-Heater Control Module C1 harness connector. Disconnect A/C-Heater Control Module C2 harness connector. Measure resistance between the A/C-Heater Control Module C2 harness connector terminal No. 2 and the Evaporator Temperature Sensor harness connector terminal No. 2. Is resistance less than 5.0 ohms? If yes, replace A/C-Heater Control Module. Perform BODY VERIFICATION TEST under VERIFICATION TESTS. If no, repair open in the Evaporator Temperature Sensor Ground circuit. Perform BODY VERIFICATION TEST under VERIFICATION TESTS.