1. Perform the antenna system test. Refer to Antenna Diagnostic Check .
2. Duplicate the condition with the ignition switch in the RUN and ACC positions.

Is the condition present?

--

Go to Step 2

System OK

Examine the electronic equipment on the vehicle.

Is the vehicle equipped with aftermarket electronic equipment?

--

Go to Step 4

Go to Step 3

Start the engine.

Is the condition still present?

--

Go to Step 5

Go to Step 8

Examine the aftermarket electronic equipment in order to determine whether the equipment is properly installed. Refer to Checking Aftermarket Accessories in Wiring Systems.

Is the aftermarket equipment installed following GM guidelines?

--

Go to Step 5

Go to Step 7

1. Remove each circuit breaker one at a time.
2. Duplicate the complaint after each circuit breaker is removed until the complaint condition stops.

Is the condition still present?

--

Go to Step 6

Go to Step 9

1. Check the integrity of the ignition system (Gasoline engines only).
2. Check for inoperative solenoids and other components that may cause poor radio reception.
3. Check the integrity of the ground of the component causing the complaint.

Is the repair complete?

--

System OK

--

Reinstall the aftermarket component according to GM guidelines.

Is the component reinstalled correctly?

--

System OK

--

Check for loose connections or poor grounds.

Is the repair complete?

--

System OK

--

Replace the circuit breaker.

Is the repair complete?

--

System OK

--