GM Service Manual Online
For 1990-2009 cars only

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Lighting Systems Connector End Views or Data Communication Connector End Views

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

2

Place the off-road lamps switch in the ON and then the OFF positions.

Does the system operate normally?

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Disconnect the off-road lamps switch.

Do the off-road lamps turn OFF?

Go to Step 6

Go to Step 4

4

  1. Reconnect the off-road lamps switch.
  2. Disconnect both off-road lamps relays, noting which one turns off the lamps. Refer to Relay Replacement .

Do the off-road lamps turn OFF?

Go to Step 5

Go to Step 8

5

Test the off-road lamps relay control circuit of the off-road lamps switch for a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 7

6

Inspect for poor connections at the harness connector of the off-road lamps switch. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 9

7

Inspect for poor connections at the harness connector of the off-road lamps relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 11

Go to Step 10

8

Repair the off-road lamps supply voltage circuit for a short to voltage. Refer to Wiring Repairs .

Did you complete the repair?

Go to Step 11

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9

Replace the off-road lamps switch. Refer to Off Road Lamp Switch Replacement .

Did you complete the replacement?

Go to Step 11

--

10

Replace the appropriate off-road lamps relay. Refer to Relay Replacement .

Did you complete the repair?

Go to Step 11

--

11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 3