GM Service Manual Online
For 1990-2009 cars only

Tools Required

J 39916-A Audio System Diagnostic Kit

Speed Test of the Cassette Player Motor

The diagnostic tape includes a 2-minute time period for the purpose of testing the motor speed of the cassette player. Use this portion of the diagnostic tape in order to verify complaints of abnormal sound from the cassette player. If the motor speed is incorrect, the sound can be abnormal. The motor speed is within tolerance if the cassette plays this portion of the tape between 1 minute, 55 seconds, and 2 minutes, 1 second.

Cassette Player Noise Diagnosis

Use the blank spaces between programs in the diagnostic tape in order to detect the following noise:

    • Alternator whine
    • Switch pops

Use this portion of the test tape for diagnostic testing. Refer to Diagnostic System Check - Radio/Audio System .