P0532

P0532-A/C SENDING UNIT VOLTS TOO LOW





For complete wiring diagrams refer to Diagrams/Electrical.


- When Monitored:

With the ignition on and battery voltage greater than 10.4 volts.

- Set Condition:

The circuit voltage to the ECM falls below a calibrated threshold for a certain period of time.







Always perform the Pre-Diagnostic Troubleshooting procedure before proceeding.

Diagnostic Test


1. OTHER DTC'S

Turn the ignition on.

With the scan tool, read DTCs.

Are other DTC's present?

Yes

- Repair other DTC's first.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 2

2. HARNESS OPEN





Disconnect the A/C pressure sending unit harness connector.

Check connectors - Clean/repair as necessary.

Measure the voltage between the (F855) 5-volt supply and (K916) return circuits of the sensor harness connector.

Is the voltage between 4.5 and 5.5 volts?

Yes

- Go To3

No

- Go To4

3. A/C PRESSURE SENSOR





While monitoring scan tool, use a jumper wire to connect the (F855) 5-volt supply circuit to the (C918) signal circuit at the sensor harness connector.

Did P0533 set?

Yes

- Replace the A/C pressure sensor.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

No

- Go To 4

4. (C918) SIGNAL CIRCUIT SHORTED TO THE (K916) RETURN CIRCUIT





Turn the ignition off.

Disconnect the ECM harness connectors.

Measure the resistance between the (C918) signal circuit and (K916) return circuit in the sensor harness connector.

Is the resistance greater than 100k Ohms?

Yes

- Go To 5

No

- Repair the (C918) signal circuit shorted to the (K916) return circuit.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

5. (F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO THE (K916) RETURN CIRCUIT





Measure the resistance between the (F855) 5-volt supply circuit and (K916) return circuit in the sensor harness connector.

Is the resistance greater than 100k Ohms?

Yes

- Go To 6

No

- Repair the (F855) 5-volt supply circuit shorted to the (K916) return circuit.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

6. (C918) SIGNAL CIRCUIT OPEN FROM ECM HARNESS CONNECTOR TO A/C HARNESS CONNECTOR





Measure the resistance of the (C918) signal circuit between the sensor harness connector and the ECM harness connector.

Is the resistance less than 10 Ohms?

Yes

- Go To 7

No

- Repair the open (C918) signal circuit.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

7. (F855) 5-VOLT SUPPLY CIRCUIT OPEN FROM ECM HARNESS CONNECTOR TO A/C HARNESS CONNECTOR





Measure the resistance of the (F855) 5-volt supply circuit between the sensor harness connector and the ECM harness connector.

Is the resistance less than 10 Ohms?

Yes

- Go To 8

No

- Repair the open (F855) 5-volt supply circuit.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

8. (C918) SIGNAL CIRCUIT SHORTED TO GROUND





Measure the resistance between the (C918) signal circuit in the sensor harness connector and battery negative.

Is the resistance greater than 100k Ohms?

Yes

- Go To 9

No

- Repair the (C918) signal circuit shorted to ground.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

9. (F855) 5-VOLT SUPPLY CIRCUIT SHORTED TO GROUND





Measure the resistance between the (F855) 5-volt supply circuit in the sensor harness connector and battery negative.

Is the resistance greater than 100k Ohms?

Yes

- Go To10

No

- Repair the (F855) 5-volt supply circuit shorted to ground.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test

10. ECM





Reconnect the ECM harness connectors.

Turn the ignition on.

While monitoring scan tool, use a jumper wire to connect the (F855) 5-volt supply circuit with the (C918) signal circuit at the sensor harness connector.

Did DTC P0533 set?

Yes

- Test Complete.

No

- Replace the ECM.
- Perform POWERTRAIN VERIFICATION TEST. Powertrain Verification Test