GM Service Manual Online
For 1990-2009 cars only

Accessory Noise (Electro Magnetic Interference)

Step

Action

Value(s)

Yes

No

1

Were you sent here from the Radio Audio Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Radio/Audio System

2

Verify the condition by test driving the vehicle and tuning to different stations.

Is the condition present regardless of vehicle location and station setting?

--

Go to Step 3

Go to Radio Poor Reception

3

Is the condition present with the key ON engine OFF?

--

Go to Step 7

Go to Step 4

4

  1. Turn the ignition switch OFF.
  2. Disconnect the generator 4 pin connector.
  3. Restart the engine.

Is the condition present?

--

Go to Step 6

Go to Step 5

5

Inspect the generator and charging system for proper operation, condition of wiring, connectors, and grounds.

Did you find and correct the condition?

--

Go to Step 9

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

6

Inspect the electronic ignition system for proper operation, condition of wiring, connectors, and grounds.

Did you find and correct the condition?

--

Go to Step 9

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

7

Inspect and if necessary repair or move ground circuits at splice packs 201 and 203.

Did you find and correct the condition?

--

Go to Step 9

Go to Step 8

8

Inspect and if necessary repair speaker feed circuit shields to and from the radio and signal processor.

Did you find and correct the condition?

--

Go to Step 9

Go to Testing for Intermittent Conditions and Poor Connections in Wiring Systems

9

  1. Clear any DTCs which may have set.
  2. Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Diagnostic System Check - Radio/Audio System