B143C

B143C-MICROPHONE 1 CIRCUIT HIGH




For a complete wiring diagram refer to Diagrams/Electrical.

- When Monitored:

With the ignition on.

- Set Condition:

The Hands Free Module detects a fault in any of the microphone circuits.






Diagnostic Test

1. CHECK FOR ACTIVE DTC

With the scan tool, read the active DTC's.

Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle.

Attempt to make a phone call with the system.

With the scan tool, read the active DTC's.

Does the scan tool display this DTC as active?

Yes

- Go To 2

No

- If the DTC is stored, check for an intermittent condition. Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.

2. INSIDE REARVIEW MIRROR





Turn the ignition off.

Disconnect the Rearview Mirror C2 harness connector.

Turn the ignition on.

With the scan tool, read the active DTC's.

Does the scan tool display this DTC as active?

Yes

- Go To 3

No

- Replace the Rearview Mirror.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

3. (X712) MICROPHONE CIRCUITS SHORTED TO VOLTAGE





Turn the ignition off.

Disconnect the Hands Free Module harness connector.

Turn the ignition on.

Measure the voltage of the (X712) Microphone circuit.

Is the voltage above 1.0 volt?

Yes

- Repair the (X712) Microphone circuit for a short to voltage.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Go To 4

4. (X712) MICROPHONE 1 IN (+) CIRCUIT OPEN




Turn the ignition off.

Measure the resistance of the (X712) Microphone 1 IN (+) circuit between the HFM connector and the inside rearview mirror connector.

Is the resistance below 5.0 ohms?

Yes

- Replace the Hands Free Module.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test

No

- Repair the (X712) Microphone 1 IN (+) circuit for an open.
- Perform BODY VERIFICATION TEST - VER 1. Body Verification Test