GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Did you perform the Lighting Systems Diagnostic System Check?

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Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Verify that the underhood lamp is inoperative.

Does the underhood lamp operate normally?

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

Go to Step 3

3

Remove the underhood lamp bulb and connect a test lamp between the socket center terminal and ground. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

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Go to Step 4

Go to Step 5

4

Replace the bulb.

Is the repair complete?

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Go to Step 8

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5

Connect a test lamp between CKT 1732 (ORN) at the underhood lamp connector and ground. Refer to Circuit Testing in Wiring Systems.

Does the test lamp illuminate?

--

Go to Step 6

Go to Step 7

6

Replace the underhood lamp assembly. Refer to Underhood Lamp Replacement .

Is the repair complete?

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Go to Step 8

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7

Repair the open or high resistance in CKT 1735 (ORN). Refer to Wiring Repairs in Wiring Systems.

Is the repair complete?

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Go to Step 8

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8

Operate the system in order to verify the repair.

Did you correct the condition?

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System OK

Go to Step 3