HVAC

901D-FLAME SENSOR CIRCUIT OPEN (ZHZ)

For a complete wiring diagram Consult Diagrams/Electrical.

- When Monitored:
Continuously.

- Set Condition:
The Warm Water Auxiliary Heating 2 Control Unit detects an open circuit.





Diagnostic Test

1. DTC IS ACTIVE
Turn the ignition on.
With the scan tool, read DTC's.
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 BODY VERIFICATION TEST - VER 1. Verification Tests.

2. CHECK FOR OPEN CIRCUIT
Turn the ignition off.
Disconnect the Warm Water Auxiliary Heating 2 Control Unit harness connector.
Disconnect the Flame Sensor harness connector.
Measure the resistance of the related circuits between the Warm Water Auxiliary Heating 2 Control Unit harness connector and the Flame Sensor harness connector.
Does the ohm meter read open circuit?

Yes

- Repair the open circuit.
- Perform BODY VERIFICATION TEST - VER 1.Verification Tests

No

- Go To 3

3. FLAME SENSOR
Turn the ignition off.
Connect the Flame Sensor harness connector.
Measure the resistance of the related circuits at the Warm Water Auxiliary Heating 2 Control Unit harness connector.
Does the ohm meter read open circuit?

Yes

- Replace the Flame Sensor.
- Perform BODY VERIFICATION TEST - VER 1.Verification Tests

No

- Replace the Warm Water Auxiliary Heating 2 Control Unit.
- Perform BODY VERIFICATION TEST - VER 1.Verification Tests