Radio
B143E - Microphone 2 Circuit Low
For a complete wiring diagram, refer to.
• When Monitored: With the ignition on.
• Set Condition: The radio detects a fault in any of the microphone circuits.
Test Step 1 - Check for Active DTC
• With the scan tool, read the active DTC's.
• Cycle the ignition switch from OFF to ON.
• 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 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.
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 DTC's.
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 radio C1 harness connector.
• Measure the resistance between ground and the Microphone 2 in (+) circuit.
Is the resistance less than 10K ohms?
Yes
• Repair the microphone 2 in (+) circuit for short to ground.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
No
• Replace the radio.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior