Auxiliary Heater (ZHZ)

901F-CIRCULATION PUMP CIRCUIT HIGH (ZHZ)

For a complete wiring diagram, Refer to the Wiring Information Electrical Diagrams.

- When Monitored:
Continuously.

- Set Condition:
The Warm Water Auxiliary Heating 2 Control Unit detects circuit shorted to voltage.





1. DTC IS ACTIVE
1. Turn the ignition on.
2. With the scan tool, read DTCs.

Is this DTC 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. Verification Tests.

2. CHECK FOR CIRCUIT SHORTED TO BATTERY
1. Turn the ignition off.
2. Disconnect the Warm Water Auxiliary Heating 2 Control Unit harness connector.
3. Disconnect the Circulation Pump harness connector.
4. Turn the ignition on.
5. Measure the voltage of the related circuits between the Warm Water Auxiliary Heating 2 Control Unit harness connector and the Circulation Pump harness connector.

Is there any voltage present?

Yes

- Repair the circuit shorted to voltage.
- Perform the BODY VERIFICATION TEST. Verification Tests

No

- Go To 3

3. CIRCULATION PUMP
1. Turn the ignition off.
2. Connect the Circulation Pump harness connector.
3. Turn the ignition on.
4. Measure the voltage of the related circuits in the Warm Water Auxiliary Heating 2 Control Unit harness connector.

Is there any voltage present?

Yes

- Repair the circuit shorted to voltage.
- Perform the BODY VERIFICATION TEST. Verification Tests.

No

- Replace the Warm Water Auxiliary Heating 2 Control Unit.
- Perform the BODY VERIFICATION TEST. Verification Tests.