1232-00

1232-00 A/C PRESSURE SENSOR CIRCUIT





- When Monitored: Engine Running with the A/C on.

- Set Condition: The A/C Heater Control Module detects an abnormally high or low voltage on the A/C Pressure Sensor Signal circuit.





Diagnostic Test

1. READ A/C PRESSURE SENSOR VOLTAGE WITH DRB III(R)





NOTE: Ensure the A/C refrigerant system is properly charged to specifications.

Turn the ignition on.

With the DRB III(R), read the A/C Pressure Sensor voltage.

Is the voltage above 4.5 volts?

Yes

- Go to 2

No

- Go to 7

2. MEASURE THE RESISTANCE FROM THE A/C PRESSURE SENSOR SIGNAL CIRCUIT TO THE 5-VoltSUPPLY CIRCUIT





Turn the ignition off.

Disconnect the A/C Pressure Sensor harness connector.

NOTE: Check connector - Clean/repair as necessary.

Disconnect the A/C Heater Control Module harness connector.

NOTE: Check connector - Clean/repair as necessary.

Measure the resistance from the A/C Pressure Sensor Signal circuit to the 5-Volt supply circuit at the A/C Pressure Sensor harness connector.

Is the resistance below 5.0 ohms?

Yes

- Repair the A/C Pressure Sensor Signal circuit for a short to the 5-Volt Supply circuit.

- Perform BODY VERIFICATION TEST. Body Verification Test

No

- Go to 3

3. MEASURE THE VOLTAGE ON THE A/C PRESSURE SENSOR SIGNAL CIRCUIT





Turn the ignition on.

Measure the voltage on the A/C Pressure Sensor Signal circuit at the A/C Pressure Sensor harness connector.

Is the voltage above 5.2 volts?

Yes

- Repair the A/C Pressure Sensor Signal circuit for a short to battery voltage.
- Perform BODY VERIFICATION TEST. Body Verification Test

No

- Go to 4

4. MONITOR A/C PRESSURE SENSOR VOLTAGE WITH DRB III(R)





Turn the ignition off.

Connect a jumper wire between the A/C Pressure Sensor Signal circuit and the Sensor ground circuit.

Turn the ignition on.

With the DRB III(R), monitor the A/C Pressure Sensor voltage.

Is the voltage below 1.0 volt?

Yes

- Replace the A/C Pressure Sensor.
- Perform BODY VERIFICATION TEST. Body Verification Test

No

- Go to 5

5. MEASURE THE RESISTANCE OF THE A/C PRESSURE SENSOR SIGNAL CIRCUIT





Turn the ignition off.

Measure the resistance of the A/C Pressure Sensor Signal circuit from the A/C Heater Control Module harness connector to the A/C Pressure Sensor harness connector.

Is the resistance below 5.0 ohms?

Yes

- Go to 6

No

- Repair the A/C Pressure Sensor Signal circuit for an open.
- Perform BODY VERIFICATION TEST. Body Verification Test

6. MEASURE THE RESISTANCE BETWEEN GROUND AND THE A/C PRESSURE SENSOR GROUND CIRCUIT





With the ignition off.

Measure the resistance between ground and the A/C Pressure Sensor Ground circuit at the A/C Pressure Sensor harness connector.

Is the resistance below 30 ohms?

Yes

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

No

- Repair the A/C Pressure Sensor ground circuit for an open.
- Perform BODY VERIFICATION TEST. Body Verification Test

7. READ A/C PRESSURE SENSOR VOLTAGE WITH DRB III(R)





With the ignition on.

With the DRB III(R), read the A/C Pressure Sensor voltage.

Is the voltage below 0.5 of a volt?

Yes

- Go to 8

No

- The condition that caused this DTC to set is currently not present. Inspect the related wiring harness for a possible intermittent condition.
- Perform BODY VERIFICATION TEST. Body Verification Test

8. MEASURE THE VOLTAGE OF THE 5-VOLT SUPPLY CIRCUIT





Turn the ignition off.

Disconnect the A/C Pressure Sensor harness connector.

NOTE: Check connector - Clean/repair as necessary.

Turn the ignition on.

Measure the voltage of the 5-Volt Supply circuit at the A/C Pressure Sensor harness connector.

Is the voltage between 4.5 and 5.0 volts?

Yes

- Go to 9

No

- Go to 12

9. MONITOR A/C PRESSURE SENSOR VOLTAGE WITH DRB III(R)





With the ignition on.

With the DRB III(R), monitor the A/C Pressure Sensor voltage.

Is the voltage above 0.5 of a volt?

Yes

- Replace the A/C Pressure Sensor.
- Perform BODY VERIFICATION TEST. Body Verification Test

No

- Go to 10

10. MEASURE THE RESISTANCE BETWEEN GROUND AND THE A/C PRESSURE SENSOR SIGNAL CIRCUIT





Turn the ignition off.

Disconnect the A/C Heater Control Module harness connector.

NOTE: Check connector - Clean/repair as necessary.

Measure the resistance between ground and the A/C Pressure Sensor Signal circuit in the A/C Pressure Sensor harness connector.

Is the resistance below 100 ohms?

Yes

- Repair the A/C Pressure Sensor Signal circuit for a short to ground.
- Perform BODY VERIFICATION TEST. Body Verification Test

No

- Go to 11

11. MEASURE THE RESISTANCE FROM THE A/C PRESSURE SENSOR SIGNAL CIRCUIT TO THE SENSOR GROUND CIRCUIT





With the ignition off.

Measure the resistance from the A/C Pressure Sensor Signal circuit to the Sensor Ground circuit at the A/C Pressure Sensor harness connector.

Is the resistance below 100 ohms?

Yes

- Repair the A/C Pressure Sensor Signal circuit for a short to the Sensor Ground circuit.
- Perform BODY VERIFICATION TEST. Body Verification Test

No

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

12. MEASURE THE RESISTANCE BETWEEN GROUND AND THE A/C PRESSURE SENSOR 5-VOLT SUPPLY CIRCUIT





Turn the ignition off.

Disconnect the A/C Heater Control Module harness connector.

Measure the resistance between ground and the 5-Volt Supply circuit at the A/C Pressure Sensor harness connector.

Is the resistance below 100 ohms?

Yes

- Repair the 5-VoltSupply circuit for a short to ground.
- Perform BODY VERIFICATION TEST. Body Verification Test

No

- Go to 13

13. MEASURE THE RESISTANCE OF THE A/C PRESSURE SENSOR 5-VOLT SUPPLY CIRCUIT





With the ignition off.

Measure the resistance of the 5-Volt Supply circuit from the A/C Pressure Sensor harness connector to the A/C Heater Control Module harness connector.

Is the resistance below 5.0 ohms?

Yes

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

No

- Repair the A/C Pressure Sensor 5-VoltSupply circuit for an open.
- Perform BODY VERIFICATION TEST. Body Verification Test