Hands Free
B143F - Microphone 2 Circuit High
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 DTC
• 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.
• Disconnect the rearview mirror harness connector.
• Turn the ignition ON.
• With the scan tool, check for active DTCs.
Does the scan tool display this DTC as active?
Yes
• Go to Test Step 3.
No
• Replace the rearview mirror.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
Test Step 3 - Microphone In 2 (+) Circuit Short to Voltage
• Turn the ignition OFF.
• Disconnect the hands free module harness connector.
• Turn the ignition ON.
• Measure the voltage on the circuit.
Is voltage present?
Yes
• Repair the circuit for a short to voltage.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
No
• Go to Test Step 4.
Test Step 4 - Microphone 2 In (+) Circuit Open
• Turn the ignition OFF.
• Measure the resistance of the circuit between the HFM connector and the inside rearview mirror connector.
Is the resistance less than 5.0 ohms?
Yes
• Replace the hands free module.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior
No
• Repair the circuit for an open.
• Perform the Body Verification Test. Refer to => Non-DTC Based Diagnostics. Body Interior