GENERAL MICROPHONE FAULT
For a complete wiring diagram Refer to Section 8W.
- When Monitored:
With the ignition on.
- Set Condition:
The Hands Free Module detects a fault in any of the microphone circuits.
| Possible Causes |
| (X712) MICROPHONE 1 IN (+) CIRCUIT OPEN |
| (X722) MICROPHONE 2 IN (+) CIRCUIT OPEN |
| (X792) MICROPHONE IN (-) CIRCUIT OPEN |
| (X712) (X722) (X792) MICROPHONE CIRCUITS SHORTED TO
GROUND |
| (X712) (X722) (X792) MICROPHONE CIRCUITS SHORTED TO VOLTAGE |
| (X712)
(X722) (X792) MICROPHONE CIRCUITS SHORTED TOGETHER |
| AUTOMATIC DAY/NIGHT MIRROR |
| HANDS FREE MODULE |
Diagnostic Test
1. CHECK FOR ACTIVE DTCTurn the ignition on.
With the scan tool, read and record the HFM DTC's and then erase the DTC's.
Attempt to make a phone call with the system.
With the scan tool, read the HFM DTC's.
Did this DTC reset?
Yes
- Go To 2
No
- The condition that set this DTC is no longer present. Using the wiring diagram/schematic as a guide, inspect the wiring for chafed, pierced, pinched, and partially broken wires and the wiring harness connectors for broken, bent, pushed out, and corroded terminals.
2. (X712) MICROPHONE 1 IN (+) CIRCUIT OPEN
Turn the ignition off.
Disconnect the Hands Free Module C1 harness connector.
Disconnect the Automatic Day/Night Mirror C2 harness connector.
Measure the resistance of the (X712) Microphone 1 IN (+) circuit between the HFM connector and the Automatic Day/Night Mirror connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 3
No
- Repair the (X712) Microphone 1 IN (+) circuit for an open.
- Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
3. (X722) MICROPHONE 2 IN (+) CIRCUIT OPEN
Measure the resistance of the (X722) Microphone 2 IN (+) circuit between the HFM connector and the Automatic Day/Night Mirror connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 4
No
- Repair the (X722) Microphone 2 IN (+) circuit for an open.
- Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
4. (X792) MICROPHONE IN (-) CIRCUIT OPEN
Measure the resistance of the (X792) Microphone IN (-) circuit between the HFM connector and the Automatic Day/Night Mirror connector.
Is the resistance below 5.0 ohms?
Yes
- Go To 5
No
- Repair the (X792) Microphone IN (-) circuit for an open.
- Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
5. (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 BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
No
- Go To 6
6. (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 BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
No
- Go To 7
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 BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
No
- Go To 8
8. AUTOMATIC DAY/NIGHT MIRROR
Replace the Automatic Day/Night 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 HFM DTC's.
Did this DTC reset?
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 BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).
No
- Repair is complete.
- Perform BODY VERIFICATION TEST – VER 1. (Refer to 8 - ELECTRICAL/ELECTRONIC CONTROL MODULES - STANDARD PROCEDURE).