Noise Diagnosis - Corrective Action

Use the correct tools for diagnosis and repairs. Be sure to follow the ESD guidelines.

The following noise suppression devices are available:
^ 220 mF (50 V) capacitor GM P/N 1227895
^ 0.47 mF capacitor GM P/N 1227894
^ Fuse block capacitor GM P/N 469328
^ Feed through capacitor GM PIN 477371
^ Filter package GM P/N 1224205
^ Turn signal suppression GM P/N 3861565
^ Fuel pump suppressor GM P/N 25027405
^ 53.3 cm (21 in) braided ground strap GM P/N 8910791
^ 48.3 cm (19 in) braided ground strap GM P/N 6286800
^ 26.7 cm (10.5 in) braided ground strap GM P/N 6287160
^ 21.6 cm (8.5 in) braided ground strap GM P/N 12091511

Use the Test Tape/CD Diagnosis Kit GM P/N J 39916-A to assist in optimizing diagnosis.

If the condition requires you to send the radio to the service center, describe the symptoms accurately on the warranty form. Send a copy of the Service Writer Check List along with the warranty form.

Take the following precautions in order to prevent damage to CD's and cassettes:
^ Do not leave CDs or cassettes in the car. Extreme heat may cause permanent damage to CDs and cassettes.
^ Store cassettes in their cases. The vibration in the vehicle may cause the tape to unwind inside of the cartridge.

Complete the following steps before you remove the speakers:
^ Inspect all of the connectors and wiring to the speakers.
^ Examine the connectors for bent or loose pins.

Complete the following steps if you use a test antenna in diagnosis:
^ Ground the antenna base to the vehicle body. Do not hold the mast.
^ Inspect the antenna coax connectors for the following conditions:
^ Corrosion
^ Poor connections
^ Crimps
^ Shield the antenna coax interconnections with aluminum or nickel tape.
^ Inspect the following grounds:
^ The radio grounds
^ The antenna grounds
^ All of the remaining grounds in the vehicle
Refer to Antenna Poor Reception (WO UV7) or Antenna Poor Reception (WI UV7) or Antenna Poor Reception (W/O UV7) or Antenna Poor Reception (WI UV7) for diagnosis.

Coated bolts and screws may be poor grounds.

Use a braided ground strap when you apply a ground. Keep the ground strap as short as possible.

For a description of the RPO Code(s) shown in this article/images refer to the RPO Code List found at Vehicle/Application ID RPO Codes