GM Service Manual Online
For 1990-2009 cars only

Step

Action

Normal Result(s)

Abnormal Result(s)*

1

With the ignition on, place the manual selector lever in the R position (manual transmission).

Place the manual selector lever in the R position (automatic transmission).

Backup lamps illuminate.

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2

With the ignition on, place the manual selector lever in any range but R.

Backup lamps go out.

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* Refer to the appropriate symptom diagnostic table for the applicable abnormal result.