CELLULAR TELEPHONE DOES NOT TRANSMIT AUDIO HANDS-FREE MODE

MODELS AFFECTED: 1989 ALLANTES

Some 1989 Allantes built prior to VIN breakpoint 101846 and equipped with the cellular telephone may not transmit audio in the hands-free mode. With this condition, the person in the vehicle is able to hear the person he or she is speaking to over the front sound system speakers; but the person they are speaking to is unable to hear the person in the vehicle. This condition may be caused by the microphone circuits being reversed in the telephone harness. To diagnose and repair this condition use the following procedure:

1. Disconnect the transceiver and the microphone.

2. Check circuits 654 and 655 for continuity from the microphone connector to the transceiver:

Check circuit 654 by probing microphone connector cavity A and transceiver connector cavity 14. The circuit will show continuity if it is OK.

Check circuit 655 by probing microphone connector cavity B and transceiver connector cavity 15. The circuit will show continuity if it is OK.

If both circuits show an open, proceed to step 4 to check for the circuits reversed. If either circuit shows continuity, proceed to step 3.

3. With transceiver and handset disconnected, check for continuity to ground from cavity A and cavity B and for continuity from A to B. If either wire is shorted to ground or if they are shorted to each other, locate damaged wiring and repair. If the wiring checks all right, refer to Chart 11 in Section 8A, cell 152 for diagnosis procedures.

4. Check for possible continuity from cavity A to cavity 15 and from cavity B to cavity 14.

5. If there is continuity measured in step 4, swap wiring at cavities A and B of the microphone connector. If there is no continuity, repair open circuit in appropriate wire.

6. Retest the cellular telephone for correct hands-free operation.

WARRANTY INFORMATION VEHICLE SERIES Operation Operation Description Number C D E J K V

Wiring and/or Connector N6100 . 5 -Repair Cellular Mobile Telephone

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Policy:

General Motors bulletins are intended for use by professional technicians, not a "do-it-yourselfer". They are written to inform those technicians of conditions that may occur on some vehicles, or to provide information that could assist in the proper service of a vehicle. Properly trained technicians have the equipment, tools, safety instructions and know-how to do a job properly and safely. If a condition is described, do not assume that the bulletin applies to your vehicle, or that your vehicle will have that condition. See a General Motors dealer servicing your brand of General Motors vehicle for information on whether your vehicle may benefit from the information.