Hands Free

B143B - Microphone 1 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, read the active DTCs.

• 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 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.

• Disconnect the inside rearview mirror harness connector.

• Turn the ignition ON.

• With the scan tool, read the DTCs.

Does the scan tool display this DTC as active?

Yes

• Go to Test Step 3.

No

• Replace the mirror.

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

Test Step 3 - Microphone 1 in (+) Circuit Short to Ground







• Turn the ignition OFF.

• Disconnect the hands free module harness connector.

• Measure the resistance between ground and the microphone 1 circuit.

Is the resistance less than 10K ohms?

Yes

• Repair the microphone 1 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