Evaporator Temperature Sensor Circuit Shorted

EVAPORATOR TEMPERATURE SENSOR CIRCUIT SHORTED

Evaporator Temperature Sensor Circuit Shorted:

WHEN MONITORED
With the ignition on.

SET CONDITION
If the A/C Heater Control senses voltage is less than 0.06 volts on the (C21) Evaporator Temperature Sensor Signal circuit.

POSSIBLE CAUSES
- (C21) Evaporator temperature sensor signal circuit shorted to ground
- (C21) Evaporator temperature sensor signal circuit shorted to (C121) sensor ground circuit
- Evaporator temperature sensor
- A/C heater control

NOTE: This DTC must be active for the results of this test to be valid. Do not perform this test if this DTC is stored. Refer to HVAC System Test for stored DTC test procedures. HVAC System Test

Diagnostic Test

1. CHECK (C21) EVAPORATOR TEMPERATURE SENSOR SIGNAL CIRCUIT VOLTAGE WITH THE SENSOR DISCONNECTED




Turn the ignition off.
Disconnect the Evaporator Temperature Sensor harness connector.
Turn the ignition on.
With the DRBIII(R) in Sensor Display, read the Evaporator Temperature Sensor voltage.

Q: Is the voltage 4.9 volts or greater?

YES: Replace the Evaporator Temperature Sensor. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 2

2. 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 of the (C21) Evaporator Temperature Sensor Signal circuit between ground and the A/C Heater Control C1 harness connector.

Q: Is the resistance below 10k ohms?

YES: Repair the (C21) Evaporator Temperature Sensor Signal circuit for a short to ground. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Go To 3

3. CHECK (C21) EVAPORATOR TEMPERATURE SENSOR SIGNAL CIRCUIT FOR A SHORT TO (C121) SENSOR GROUND CIRCUIT




Measure the resistance between the (C21) Evaporator Temperature Sensor Signal circuit and the (C121) Sensor Ground circuit in the A/C Heater Control C1 harness connector.

Q: Is the resistance below 10k ohms?

YES: Repair the (C21) Evaporator Temperature Sensor Signal circuit for a short to the (C121) Sensor Ground circuit. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test
NO: Replace the A/C Heater Control. Perform BODY VERIFICATION TEST - VER 1. Body Verification Test