B143A-92

B143A-92-MICROPHONE 1 - PERFORMANCE OR INCORRECT OPERATION





For a complete wiring diagram, refer to the Wiring Information.

Theory of Operation

The Hands Free Module (HFM) controls and monitors both the (X712) microphone 1 input circuit (+) and the (X792) microphone 1 input circuit (-) for a concern. The HFM communicates over the CAN-AT Bus. The microphone is located in the rearview mirror.

For a detailed description of the Hands Free System. Hands Free Module - Description.

For additional information regarding the operation of the Hands Free System. Hands Free Module - Operation.

- When Monitored:
With the ignition on.

- Set Condition:
The HFM detects the (X712) Microphone 1 IN (+) circuit is shorted to the (X792) Microphone 1 IN (-) circuit for greater than 10 seconds.





1. CHECK FOR ACTIVE DTC

NOTE: Verify the connection of the Rearview Mirror harness connector.

1. Turn the ignition on.
2. With the scan tool, read the active DTCs.

Does the scan tool display: B143A 92-MICROPHONE 1 - PERFORMANCE OR INCORRECT OPERATION as active?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals and correct pin tension.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. CHECK THE INSIDE REARVIEW MIRROR




1. Turn the ignition off.
2. Disconnect the Inside Rearview Mirror harness connector.
3. Turn the ignition on.
4. With the scan tool, read the active DTCs.

NOTE: B143A-13-MICROPHONE 1 - CIRCUIT OPEN should display as active as a result of this test.

Does the scan tool display: B143A 92-MICROPHONE 1 - PERFORMANCE OR INCORRECT OPERATION as active?

Yes

- Go To 3

No

- Replace the Inside Rearview Mirror.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

3. CHECK THE (X712) MICROPHONE 1 IN (+) AND THE (X792) MICROPHONE 1 IN (-) CIRCUITS FOR A SHORT TOGETHER




1. Turn the ignition off.
2. Disconnect the Hands Free Module harness connector.
3. Measure the resistance between the (X712) Microphone 1 IN (+) circuit, and the (X792) Microphone 1 IN (-) circuit.

Is the resistance below 10K Ohms?

Yes

- Repair the (X712) Microphone 1 IN (+) and the (X792) Microphone 1 IN (-) circuits for a short together.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Replace the Hands Free Module. Hands Free Module - Removal.
- Perform the BODY VERIFICATION TEST. Body Verification Test.