B1492

B1492-GENERAL MICROPHONE PERFORMANCE





For a complete wiring diagram, refer to the Wiring Information Electrical Diagrams.

- When Monitored:
With the ignition on.

- Set Condition:
The Hands Free Module detects a fault in any of the microphone circuits.





1. CHECK FOR ACTIVE DTC
1. With the scan tool, read the active DTCs.
2. Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle.
3. Attempt to make a phone call with the system.
4. With the scan tool, read the active DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 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.

2. (X712) MICROPHONE 1 IN (+) CIRCUIT OPEN




1. Turn the ignition off.
2. Disconnect the Hands Free Module harness connector.
3. Disconnect the Inside Rear View Mirror C2 harness connector.
4. 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 3

No

- Repair the (X712) Microphone 1 IN (+) circuit for an open.
- Perform the BODY VERIFICATION TEST Body Verification Test.

3. (X722) MICROPHONE 2 IN (+) CIRCUIT OPEN




1. 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 4

No

- Repair the (X722) Microphone 2 IN (+) circuit for an open.
- Perform the BODY VERIFICATION TEST Body Verification Test.

4. (X792) MICROPHONE IN (-) CIRCUIT OPEN




1. 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 5

No

- Repair the (X792) Microphone IN (-) circuit for an open.
- Perform the BODY VERIFICATION TEST Body Verification Test.

5. (X712) (X722) (X792) MICROPHONE CIRCUITS SHORTED TO GROUND




1. 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 Body Verification Test.

No

- Go To 6

6. (X712) (X722) (X792) MICROPHONE CIRCUITS SHORTED TO VOLTAGE




1. Turn the ignition on.
2. 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 Body Verification Test.

No

- Go To 7

7. (X712) (X722) (X792) MICROPHONE CIRCUITS SHORTED TOGETHER




1. Turn the ignition off.
2. 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 Body Verification Test.

No

- Go To 8

8. INSIDE REAR VIEW MIRROR
1. Replace the Inside Rear View Mirror.
2. Cycle the ignition switch from off to on at least 5 times, leaving the ignition on for a minimum of 90 seconds per cycle.
3. Attempt to make a phone call with the system.
4. 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.
- Perform the BODY VERIFICATION TEST Body Verification Test.

No

- Repair is complete.
- Perform the BODY VERIFICATION TEST Body Verification Test.