Diagnostic Test
- CHECK FOR ACTIVE DTC
- 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 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.
- (X712) MICROPHONE 1 IN (+) CIRCUIT OPEN
- Turn the ignition off.
- Disconnect the Hands Free Module harness connector.
- Disconnect the Inside Rear View Mirror C2 harness connector.
- Measure the resistance of the (X712) Microphone 1 IN (+) circuit between the HFM connector and the inside rear view mirror connector.
Is the resistance below 5.0 ohms?
Yes
- Go to step 3
No
- Repair the (X712) Microphone 1 IN (+) circuit for an open.
- Perform the BODY VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
- (X722) MICROPHONE 2 IN (+) CIRCUIT OPEN
- Measure the resistance of the (X722) Microphone 2 IN (+) circuit between the HFM connector and the inside rear view mirror connector.
Is the resistance below 5.0 ohms?
Yes
- Go to step 4
No
- Repair the (X722) Microphone 2 IN (+) circuit for an open.
- Perform the BODY VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
- Measure the resistance of the (X722) Microphone 2 IN (+) circuit between the HFM connector and the inside rear view mirror connector.
- (X792) MICROPHONE IN (-) CIRCUIT OPEN
- Measure the resistance of the (X792) Microphone IN (-) circuit between the HFM connector and the inside rear view mirror connector.
Is the resistance below 5.0 ohms?
Yes
- Go to step 5
No
- Repair the (X792) Microphone IN (-) circuit for an open.
- Perform the BODY VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
- Measure the resistance of the (X792) Microphone IN (-) circuit between the HFM connector and the inside rear view mirror connector.
- (X712) (X722) (X792) MICROPHONE CIRCUITS SHORTED TO GROUND
- Measure the resistance between ground and each (X712) (X722) (X792) Microphone circuit.
Is the resistance below 100.0 ohms?
Yes
- Repair the Microphone circuit that measured below 100.0 ohms for short to ground.
- Perform the BODY VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
No
- Go to step 6
- Measure the resistance between ground and each (X712) (X722) (X792) Microphone circuit.
- (X712) (X722) (X792) MICROPHONE CIRCUITS SHORTED TO VOLTAGE
- Turn the ignition on.
- Measure the voltage of each (X712) (X722) (X792) Microphone circuit.
Is the voltage above 1.0 volt?
Yes
- Repair the Microphone circuit that measured above 1.0 volt for short to voltage.
- Perform the BODY VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
No
- Go to step 7
- (X712) (X722) (X792) MICROPHONE CIRCUITS SHORTED TOGETHER
- Turn the ignition off.
- Measure the resistance between each (X712) (X722) (X792) Microphone circuit.
Is the resistance below 100.0 ohms?
Yes
- Repair the Microphone circuit that measured below 100.0 ohms for a short together.
- Perform the BODY VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
No
- Go to step 8
- INSIDE REAR VIEW MIRROR
- Replace the Inside Rear View Mirror in accordance with the service information.
- 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
- Inspect the wiring and connectors for damage or shorted circuits. If OK, replace and program the Hands Free Module in accordance with the service information.
- Perform the BODY VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .
No
- Repair is complete.
- Perform the BODY VERIFICATION TEST. Refer to DTC-Based Diagnostics/MODULE, Front Control (FCM) - Standard Procedure .