General Microphone Fault

GENERAL MICROPHONE FAULT





For a complete wiring diagram Consult Diagrams/Electrical

- When Monitored:
With the ignition on.

- Set Condition:
The HFM detects a fault on the (X712/X722/X792) Microphone circuits.





Diagnostic Test

1. VERIFY ACTIVE DTC
Turn the ignition on.
With the scan tool, erase DTCs.
Attempt to make a phone call using the system.
With the scan tool, read DTCs.
Does the scan tool display this DTC as active?

Yes

- Go To2

No

- Go To7

2. MICROPHONE CIRCUITS OPEN




Turn the ignition off.
Disconnect the Rear View Mirror harness connector.
Disconnect the Hands Free Module harness connector.
Measure the resistance of each Microphone circuit (X712/X722/X792) between the HFM connector and the rear view mirror connector.
Is the resistance below 10.0 ohms for each measurement?

Yes

- Go To3

No

- Repair the Microphone circuits for an open.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test.

3. MICROPHONE CIRCUITS SHORT TO GROUND




Turn the ignition off.
Disconnect the Rear View Mirror harness connector.
Disconnect the Hands Free Module harness connector.
Measure the resistance between ground and each Microphone circuit (X712/X722/X792).
Is the resistance above 1000.0 ohms for each measurement?

Yes

- Go To4

No

- Repair the Microphone circuits for a short to ground.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test.

4. MICROPHONE CIRCUITS SHORT TO VOLTAGE




Turn the ignition off.
Disconnect the Rear View Mirror harness connector.
Disconnect the Hands Free Module harness connector.
Turn the ignition on.
Measure the voltage of each Microphone circuit (X712/X722/X792).
Is the voltage below 1.0 volt for each measurement?

Yes

- Go To5

No

- Repair the Microphone circuits for a short to voltage.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test.

5. MICROPHONE CIRCUITS SHORTED TOGETHER




Turn the ignition off.
Disconnect the Rear View Mirror harness connector.
Disconnect the Hands Free Module harness connector.
Measure the resistance between each Microphone circuit (X712/X722/X792) in the rear view mirror harness connector.
Is the resistance above 1000 ohms for each measurement?

Yes

- Go To6

No

- Refer the Microphone circuits for a short together.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test.

6. REAR VIEW MIRROR
Replace the Rear View Mirror.
Turn the ignition on.
With the scan tool, erase DTC's.
Attempt to make a phone call using the system.
With the scan tool, read DTCs.
Does the scan tool display this DTC?

Yes

- Inspect the wiring and connectors for damage or shorted circuits. Repair as necessary. If ok, replace and program the Hands Free Module .
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test.

No

- Test complete.

7. INTERMITTENT CONDITION

NOTE: The conditions that set the DTC are not present at this time. The following list may help in identifying the intermittent condition.

With the engine running at normal operating temperature, wiggle the wiring harnesses. This is to try and duplicate the failure.
Search for any Technical Service Bulletins (TSB) that may apply.
Visually inspect the related wiring harness. Look for any chafed, pierced, pinched, or partially broken wires.
Visually inspect the related wiring harness connectors. Look for broken, bent, pushed out, or corroded terminals.
Were any of the above conditions present?

Yes

- Repair as necessary.
- Perform the BODY VERIFICATION TEST - VER 1. Body Verification Test.

No

- Test complete.