GM Service Manual Online
For 1990-2009 cars only
  1. Inspect Circuit Breaker #22 to determine if it is open. If an open condition exists, Locate and repair the cause of the overload and replace the circuit breaker.
  2. Inspect grounds G105 and G406 to make certain that they are clean and tight.
  3. Inspect for broken (or partially broken) wire inside the insulation. This condition could cause system malfunction but prove to test good in a continuity or voltage test with the system disconnected. These circuits may be intermittent or resistive when in operation. If possible test for a voltage drop when the system is operational.
  4. Inspect for proper installation of aftermarket electronic equipment which may affect the integrity of other systems.