No Response From HVAC (A/C Heater Control - MTC)

*NO RESPONSE FROM HVAC (A/C HEATER CONTROL - MTC)





For a complete wiring diagram Consult Diagrams/Electrical.





Diagnostic Test

1. TEST FOR INTERMITTENT CONDITION
NOTE: Check for any TSB(s) related to the condition. If a TSB applies, perform the procedure outlined in the TSB before continuing.

Turn the ignition on.

NOTE: Ensure the IOD fuse is installed and battery voltage is between 10.0 and 16.0 volts.

With the scan tool, select ECU View.

NOTE: A red X will be next to the module that is not communicating, indicating that the module is not active on the Bus network. A green check indicates that the module is active on the Bus network.

Does the scan tool display a red X next to the module?

Yes

- Go to 2

No

- The no response condition is not present at this time. Using the wiring diagram/schematic as a guide, inspect the wiring for chafed, pierced, pinched, and partially broken wires and the wiring harness connectors for broken, bent, pushed out, and corroded terminals.

2. (Z912) GROUND CIRCUIT OPEN




Turn the ignition off.
Disconnect the A/C Heater Control C1 harness connector.
Using a 12 volt test light connected to 12 volts check the (Z912) ground circuit.
Does the test light illuminate brightly?

Yes

- Go to 3

No

- Repair the (Z912) ground circuit for an open.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test.

3. (F929) FUSED IGNITION SWITCH OUTPUT (RUN) CIRCUIT OPEN OR SHORTED




Turn the ignition on.
Using a 12-volt test light connected to ground, check the (F929) Fused Ignition Switch Output (RUN) circuit.
Does the test light illuminate brightly?

Yes

- Go to 4

No

- Repair the (F929) Fused Ignition Switch Output (RUN) circuit for an open or short.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test.

4. (D55) AND (D54) CAN B BUS CIRCUITS OPEN




NOTE: One open circuit will not cause this condition.

Measure the voltage between the (D54) CAN B Bus (-) circuit and ground.
Measure the voltage between the (D55) CAN B Bus (+) circuit and ground.
Is there any voltage present on either circuit?

Yes

- Replace the Occupant Restraint Controller Module.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test.

No

- Repair the (D55) and (D54) CAN B Bus circuits for an open. Inspect the connector for damage.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test.