To determine if backway noise is present, perform the following steps:

1. Place the ignition switch in the ACCY position.
2. Seek up the band range from (88 FM) and (550 AM) to the top of each band.
3. Count the number of valid stations the tuner stops at on each band.
4. Listen for various noise problems.
5. Perform steps two through four with the ignition switch in the ON position and the engine OFF.
6. Perform steps two through four with the ignition switch in the ON position and the engine running.

These steps (5 and 6) can help determine which components are causing the interference problem. For example, if the same number of stations are received with the engine running as when the engine was off, the components active with the engine running are NOT causing the interference.

If noise is not sideway or frontway and it is still heard at minimum volume, then backway noise is present.

Backway noise may be related to other harnesses and could be intermittent depending on the component causing the problem.

To correct the problem, Audio Preliminary Diagnosis , and complete the remaining steps.