GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2000 🢒 Seville 🢒 Body and Accessories 🢒 Stationary Windows 🢒 Backup Lamps Inoperative

Step

Action

Value(s)

Yes

No

1

Did you perform the Lighting Systems Diagnostic System Check?

--

Go to Step 2

Go to Diagnostic System Check - Lighting Systems

2

Check the rear fuse block NSBU fuse for an open?

Is the NSBU fuse OK?

--

Go to Step 3

Go to Step 10

3
  1. Connect a scan tool to the data link connector (DLC).
  2. Select OUTPUT CONTROLS from the rear integration module (RIM) SPECIAL FUNCTIONS.
  3. Command the backup lights to turn on.

Do the backup lights turn on?

--

Go to Diagnostic Starting Point - Automatic Transmission in Automatic Transaxle - 4T80 - E

Go to Step 4

4
  1. Select INPUTS from the rear integration module (RIM) DATA DISPLAY
  2. Place the gear selector in the REVERSE position.

Does the scan tool show that the reverse relay output is on?

--

Go to Step 5

Go to Diagnostic Starting Point - Automatic Transmission in Automatic Transaxle - 4T80 - E

5

Backprobe the rear fuse block with a DMM from connector C1 cavity B7 (DK GRN) to ground.

Is the voltage within the specified range?

10-15 V

Go to Step 6

Go to Step 15

6
  1. Turn the ignition switch to the ON position.
  2. Place the gear selector in the REVERSE position.
  3. Backprobe the rear fuse block with a DMM from connector C1 cavity B7 (DK GRN) to ground.

Is the voltage less than the specified value?

0.5 V

Go to Step 7

Go to Step 16

7

Backprobe the rear fuse block with a DMM from connector C1 cavity C8 (LT GRN) to ground.

Is the voltage within the specified range?

10-15 V

Go to Step 8

Go to Step 15

8
  1. Disconnect connector C402.
  2. Backprobe connector C402 with a DMM from cavity B (BLK) to cavity C (LT GRN).

Is the voltage within the specified range?

10-15 V

Go to Step 9

Go to Step 14

9

Inspect CKT 24 (LT GRN) between connector C402 and splice S410 for an open. Refer to Testing for Continuity in Wiring Systems.

Was an open found?

--

Go to Step 12

Go to Step 13

10
  1. Disconnect the rear fuse block connector C1.
  2. Disconnect the LH and RH backup lamp connectors.
  3. Backprobe with a DMM from the rear fuse block connector C1 cavity C8 (LT GRN) to ground.

Is the resistance less than the specified value?

OL

Go to Step 12

Go to Step 11

11

Replace the rear fuse block. Refer to Rear Electrical Center or Junction Block Replacement in Wiring Systems.

Is the rear fuse block replacement complete?

--

Go to Step 17

--

12

Repair the open or short to ground in CKT 24 (LT GRN) between connector C402 and splice S410. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Step 17

--

13

Repair the open in CKT 850 (BLK) between connector C402 and splice S413. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Step 17

--

14

Repair the open in CKT 650 (BLK) between connector C402 and ground G402. Refer to Wiring Repairs in Wiring Systems.

Is the circuit repair complete?

--

Go to Step 17

--

15

Replace the REVERSE relay in the rear fuse block.

Is the relay replacement complete?

--

Go to Step 17

--

16

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

Is the RIM replacement complete?

--

Go to Step 17

--

17

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK.

Go to Step 2