B143A-12

B143A-12-MICROPHONE 1 - CIRCUIT SHORT TO BATTERY

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

Theory of Operation

The Telematics Gateway (TGW) controls and monitors both the (X712) microphone 1 input circuit (+) and the (X792) microphone 1 input circuit (-) for a concern. The TGW communicates over the CAN-AT Bus and the CAN-Interior Bus. The microphone is located in the rearview mirror.

- When Monitored:
With the ignition on.

- Set Condition:
The TGW detects a short to battery voltage on either the (X712) Microphone 1 IN (+) or the (X792) Microphone 1 IN (-) circuits for greater than 10 seconds.





1. CHECK FOR AN ACTIVE DTC

NOTE: Verify the connection of the inside rearview mirror harness connector.

1. Ignition on, engine not running.
2. With the scan tool, read the DTCs.

Does the scan tool display: B155C-12-MICROPHONE 1 CIRCUIT (+) - CIRCUIT SHORT TO BATTERY 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.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

2. CHECK THE INSIDE REARVIEW MIRROR
1. Turn the ignition off.
2. Disconnect the Inside Rearview Mirror harness connector.
3. Ignition on, engine not running.
4. Wait 20 seconds.
5. With the scan tool, read the active DTCs.

Does the scan tool display: B155C-12-MICROPHONE 1 CIRCUIT (+) - CIRCUIT SHORT TO BATTERY as active?

Yes

- Go To 3

No

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

3. CHECK THE (X712) MICROPHONE 1 IN (+) CIRCUIT FOR A SHORT TO VOLTAGE
1. Turn the ignition off.
2. Disconnect the TGW connector.
3. Ignition on, engine not running.
4. Measure the voltage between the (X712) Microphone 1 IN (+) circuit and ground.

Is there any voltage present?

Yes

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

No

- Go To 4

4. CHECK THE (X792) MICROPHONE 1 IN (-) CIRCUIT FOR A SHORT TO VOLTAGE
1. Measure the voltage between the (X712) Microphone 1 IN (+) circuit and ground.

Is there any voltage present?

Yes

- Repair the short to voltage in the (X792) Microphone 1 IN (-) circuit.
- Perform the BODY VERIFICATION TEST. Body Verification Test.

No

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