B143A

B143A-MICROPHONE 1 CIRCUIT PERFORMANCE





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

- When Monitored:
With the ignition on.

- Set Condition:
The Radio detects a fault in any of the microphone circuits.





1. CHECK FOR ACTIVE DTC
1. Turn the ignition on.
2. With the scan tool, read the active DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 2

No

- Test complete, the condition or conditions that originally set this DTC are not present at this time. Using the wiring diagrams as a guide, check all related splices and connectors for signs of water intrusion, corrosion, pushed out or bent terminals and correct pin tension.

2. INSIDE REARVIEW MIRROR
1. Turn the ignition off.
2. Disconnect the Inside Rearview Mirror C2 harness connector.
3. Turn the ignition on.
4. With the scan tool, read the DTCs.

Does the scan tool display this DTC as active?

Yes

- Go To 3

No

- Replace the Inside Rearview Mirror.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

3. (X712) MICROPHONE 1 IN (+) CIRCUIT SHORTED TO GROUND
1. Turn the ignition off.
2. Disconnect the Radio C2 harness connector.
3. Measure the resistance between ground and the (X712) Microphone 1 circuit.

Is the resistance below 10K Ohms?

Yes

- Repair the (X712) Microphone 1 circuit for short to ground.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 4

4. (X712) MICROPHONE 1 IN (+) CIRCUIT SHORTED TO VOLTAGE
1. Turn the ignition on.
2. Measure the voltage of the (X712) Microphone 1 IN (+) circuit.

Is voltage present?

Yes

- Repair the (X712) Microphone 1 IN (+) circuit for a short to voltage.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

- Go To 5

5. (X712) MICROPHONE 1 IN (+) CIRCUIT OPEN
1. Measure the resistance of the (X712) Microphone 1 IN (+) circuit between the Radio C2 connector and the Inside Rearview Mirror C2 harness connector.

Is the resistance below 5.0 Ohms?

Yes

- Replace the Radio.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

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