GM Service Manual Online
For 1990-2009 cars only

Step

Action

Value(s)

Yes

No

1

Was the entire Backup Lights System Check performed?

--

Go to Step 2

Go to Backup Lamp System Check

2

Disconnect the rear integration module (RIM) connector C1.

Do the backup lamps turn off?

--

Go to Step 6

Go to Step 3

3

Remove the REVERSE relay from the rear junction block.

Do the backup lamps turn off?

--

Go to Step 7

Go to Step 4

4

Disconnect the rear junction block connector C1.

Do the backup lamps turn off?

--

Go to Step 9

Go to Step 5

5

Repair the short to battery positive voltage (B+) in CKT 24 (LT GRN). Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Backup Lamp System Check

--

6

Replace the rear integration module (RIM). Refer to Body Control Module Replacement in Body Control System.

Is the RIM replacement complete?

--

Go to Backup Lamp System Check

--

7

Connect a DMM from the rear integration module (RIM) connector C1 cavity A8 (DK GRN) to ground.

Is the resistance less than the specified value?

5 ohms

Go to Step 8

Go to Step 10

8

Replace the REVERSE relay in the rear junction block. Refer to Wiring Repairs in Wiring Systems.

Do the backup lamps now operate properly?

--

Go to Backup Lamp System Check

Go to Step 9

9

Replace the rear junction block. Refer to Rear Junction Block Replacement.

Is the rear junction block replacement complete?

--

Go to Backup Lamp System Check

--

10

Repair the short to ground in CKT 646 (DK GRN). Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Backup Lamp System Check

--