B143A- MICROPHONE 1 CIRCUIT PERFORMANCE

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

Possible Causes
(X712) MICROPHONE 1 IN (+) CIRCUIT SHORTED TO GROUND
(X712) MICROPHONE 1 IN (+) CIRCUIT OPEN
(X712) MICROPHONE 1 IN (+) CIRCUITS SHORTED TO VOLTAGE
(X792) MICROPHONE IN (-) CIRCUIT SHORTED TO GROUND
(X792) MICROPHONE IN (-) CIRCUIT OPEN
(X792) MICROPHONE IN (-) CIRCUITS SHORTED TO VOLTAGE
HANDS FREE MICROPHONE
RADIO

1. CHECK FOR ACTIVE DTC

1.	Turn the ignition on.

2.	With the scan tool, read the active DTCs.

Does the scan tool display B143A- MICROPHONE 1 CIRCUIT PERFORMANCE as active?

Yes

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. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure).

2. CHECK THE HANDS FREE MICROPHONE

1.	Turn the ignition off.

2.	Disconnect the Hands Free Microphone harness connector.

3.	Turn the ignition on.

4.	With the scan tool, read the active DTCs.

Does the scan tool display B143A- MICROPHONE 1 CIRCUIT PERFORMANCE as active?

Yes

Replace the Hands Free Microphone in accordance with the Service Information.
Perform the BODY VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure).

3. CHECK THE (X712) MICROPHONE 1 IN (+) AND (X792) MICROPHONE IN (-) CIRCUITS FOR A SHORT TO GROUND

1.	Turn the ignition off.

2.	Disconnect the Radio C1 harness connector.

3.	Measure the resistance between ground and the (X712) Microphone 1 IN (+) circuit.

4.	Measure the resistance between ground and the (X792) Microphone IN (-) circuit.

Is the resistance below 10K Ohms?

Yes

Repair the (X712) Microphone 1 IN circuit or the (X792) Microphone IN (-) circuit for short to ground.
Perform the BODY VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure).

4. CHECK THE (X712) MICROPHONE 1 IN (+) AND THE (X792) MICROPHONE IN (-) CIRCUITS FOR A SHORT TO VOLTAGE

1.	Turn the ignition on.

2.	Measure the voltage between ground and the (X712) Microphone 1 IN (+) circuit.

3.	Measure the voltage between ground and the (X792) Microphone 1 IN (-) circuit.

Is the voltage above 1.0 volt?

Yes

Repair the (X712) Microphone 1 IN (+) circuit or the (X792) Microphone 1 IN (-) circuit for a short to voltage.
Perform the BODY VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure).

5. CHECK THE (X712) MICROPHONE 1 IN (+) CIRCUIT FOR AN OPEN

1.	Turn the ignition off.

2.	Measure the resistance of the (X712) Microphone 1 IN (+) circuit.

Is the resistance below 5.0 Ohms?

Yes

Repair the (X712) Microphone 1 IN (+) or the (X792) Microphone IN (-) circuit for an open.
Perform the BODY VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure).

6. CHECK THE (X792) MICROPHONE 1 IN (-) CIRCUIT FOR AN OPEN

1.	Measure the resistance of the (X792) Microphone IN (-) circuit.

Is the resistance below 5.0 Ohms?

Yes

Replace the Radio in accordance with the Service Information.
Perform the BODY VERIFICATION TEST. (Refer to 28 - DTC-Based Diagnostics/MODULE, Totally Integrated Power (TIPM) - Standard Procedure).