Operation CHARM: Car repair manuals for everyone.

Hands Free






B143E - Microphone 2 Circuit Low






For a complete wiring diagram, refer to.

When Monitored: With the ignition on.

Set Condition: The hands free module detects a fault in any of the microphone circuits.






Test Step 1 - Check for Active DTCs

With the scan tool, check for active DTCs.

Cycle the ignition switch from OFF to ON.

Attempt to make a phone call with the system.

With the scan tool, check for active DTCs.

Does the scan tool display this DTC as active?

Yes

Go to Test Step 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.

Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

Test Step 2 - Inside Rearview Mirror







Turn the ignition OFF.

Turn the ignition OFF.

Disconnect the inside rearview mirror C2 harness connector.

Turn the ignition ON.

With the scan tool, check for DTCs.

Does the scan tool display this DTC as active?

Yes

Go to Test Step 3.

No

Replace the inside rearview mirror..

Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

Test Step 3 - Microphone 2 In (+) Circuit Short to Ground







Turn the ignition OFF.

Disconnect the hands free module harness connector.

Measure the resistance between ground and the microphone 2 circuit.

Is the resistance less than 10K ohms?

Yes

Repair the circuit for a short to ground.

Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior

No

Replace the hands free module.

Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior