Auxiliary Heater (ZHZ)

9027-YELLOW LED CIRCUIT OPEN (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 an open circuit.





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. HEATER BOOSTER BUTTON
1. Turn the ignition off.
2. Replace the Heater Booster Button with a known good Heater Booster Button.
3. Turn the ignition on.
4. With the scan tool, read DTCs.

Is this DTC active?

Yes

- Go To 3

No

- Replace the Heater Booster Button.
- Perform the BODY VERIFICATION TEST. Verification Tests.

3. CHECK FOR OPEN CIRCUIT
1. Turn the ignition off.
2. Disconnect the Warm Water Auxiliary Heating 2 Control Unit harness connector.
3. Disconnect the Heater Booster Button harness connector.
4. Measure the resistance of the related circuits between the Warm Water Auxiliary Heating 2 Control Unit harness connector and the Heater Booster Button harness connector.

Does the Ohm meter read open circuit?

Yes

- Repair the open circuit.
- Perform the BODY VERIFICATION TEST. Verification Tests.

No

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