For 1990-2009 cars

Step | Action | Value(s) | Yes | No
--- | --- | --- | --- | ---
1 | Did you perform the radio/audio system diagnostic system check? | -- | Go to Step 2 | Go to Audio Preliminary Diagnosis
2 | Attempt to duplicate the abnormal condition in each ignition switch key position. Is the condition present? | -- | Go to Step 3 | Go to Step 4
3 |

1. Read the technical service bulletins.
2. Make any necessary repairs.
3. Test the system again for the condition.

Is the condition still present?

--

Go to Step 5

--

4 | Contact the customer for an explanation of the faulty condition. Test the system again. Is the system OK? | -- | Go to Audio Preliminary Diagnosis | --
5 | Is the vehicle equipped with aftermarket electronic equipment? | -- | Go to Step 5 | Go to Step 6
6 | Inspect for proper installation of the aftermarket electronic equipment. Refer to Checking Aftermarket Accessories in Wiring Systems. Were GM aftermarket installation guidelines followed? | -- | Go to Step 8 | Go to Step 9
7 |

1. Test the integrity of the ignition system for the following:

• | Proper spark wire routing

• | Ignition misfire

2. Test the integrity of all engine compartment grounds.
3. Test for malfunctions in the following components:

• | The relays

• | The solenoids

• | Other components which may cause reduced reception

Is the system OK?

--

Go to Audio Preliminary Diagnosis

--

8 | Remove the fuses and the circuit breakers one at a time until the faulty circuit has been identified. Have you identified the faulty circuit? | -- | Go to Step 10 | Go to Step 12
9 |

1. Correct the improper installation.
2. Re-test the system for the fault condition

Did you complete the repair?

--

Go to Audio Preliminary Diagnosis

--

10 |

• | Mark the fuses of the faulty circuit.

• | Re-install all of the fuses and circuit breakers. Refer to Power Distribution Schematics in Wiring Systems to identify all of the systems and the components powered through the marked fuse(s) and/or circuit breaker(s).

Has the appropriate component been identified?

--

Go to Step 11

--

11 | Inspect the ground integrity of the component. Refer to Testing for Short to Ground in Wiring Systems. Is the ground of the component OK? | -- | Go to Audio Preliminary Diagnosis | Go to Step 12
12 | Repair the faulty circuit. Refer to Wiring Repairs in Wiring Systems. Is the repair complete? | -- | Go to Audio Preliminary Diagnosis | --