B2455

DTC B2455

CIRCUIT DESCRIPTION
The vehicle communication interface module (VCIM) detects that the cellular microphone is connected through the cellular microphone signal circuit and the drain wire.

DTC DESCRIPTOR
This diagnostic procedure supports the following DTC:
DTC B2455 Cellular Phone Microphone Circuit Malfunction




This vehicle has DTCs which include DTC Symptoms. For more information on DTC Symptoms, refer to DTC Symptom Description in Vehicle DTC Information. DTC Symptom Description

CONDITIONS FOR RUNNING THE DTC
- The ignition must be in the RUN or ACC position.
- The system voltage is at least 9.5 volts and no more than 15.5 volts.
- All the above conditions are present for greater than 10 seconds.

CONDITIONS FOR SETTING THE DTC
- The VCIM detects an open in the drain wire circuit or a short to voltage in the cellular microphone signal circuit.
- The above conditions are present for greater than 10 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The VCIM will not receive any signal from the microphone.
- Calls can be placed, but the caller cannot be heard.
- The OnStar(R) status LED turns red.

CONDITIONS FOR CLEARING THE DTC
- The VCIM detects the microphone connected for 5 consecutive 100 millisecond cycles.
- A history DTC clears after 50 malfunction-free ignition cycles.
- The VCIM receives the clear DTC command from the scan tool.

TEST DESCRIPTION

Step 1- Step 9:

The number below refers to the step number on the diagnostic table.
2. This step checks that the VCIM is sending out the proper supply voltage.