B1031

B1031-EVAPORATOR FIN TEMPERATURE SENSOR CIRCUIT LOW





For a complete wiring diagram Consult Diagrams/Electrical.

- When Monitored:
With the ignition on.

- Set Condition:
If the Evaporator Temperature Sensor input is out of range toward the low voltage threshold.





Diagnostic Test

1. ACTIVE DTC(S) PRESENT
Turn the ignition on.
Using the A/C Heater Control, turn the heater on.
With the scan tool, check for DTCs.
Does the scan tool display this DTC as active?

Yes

- Go to 2

No

- The condition that caused this symptom is currently not present. Check for an intermittent condition by inspecting the related wiring harness for chafed, pierced, pinched, and partially broken wires. Also, inspect the related connectors for broken, bent, pushed out, spread, corroded, or contaminated terminals. Repair as necessary.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test.

2. CHECK FOR DTC WITH THE EVAPORATOR TEMPERATURE SENSOR HARNESS CONNECTOR DISCONNECTED
Turn the ignition off.
Disconnect the Evaporator Temperature Sensor Harness Connector.
Turn the ignition on.
With the scan tool, erase HVAC DTCs.
Turn the ignition off, wait 10 seconds, and turn the ignition on.
With the scan tool, read HVAC DTCs.
Does the scan tool display this DTC as active?

Yes

- Go to 3.

No

- Replace the Evaporator Temperature Sensor.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.

3. CHECK (C21) EVAPORATOR TEMPERATURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO GROUND




Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Measure the resistance between ground and the (C21) Evaporator Temperature Sensor Signal circuit in the A/C Heater Control C1 harness connector.
Does the ohm meter read open circuit?

Yes

- Replace the A/C Heater Control.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.

No

- Repair the (C21) Evaporator Temperature Sensor Signal circuit for a short to ground.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test.