GM Service Manual Online
For 1990-2009 cars only

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Listen for an audible click when the PERIM LP relay operates. Command both the ON and OFF states. Repeat the commands as necessary.

  2. Tests for voltage at the control side of the PERIM LP relay.

  3. Verifies that the control module is providing ground to the PERIM LP relay.

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Master Electrical Component List in Wiring Systems

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Turn ON the ignition, with the engine OFF.
  2. Depress and hold the brake pedal.
  3. Move the gear selector through the gear ranges.
  4. Observe the backup lamps.
  5. Place the gear selector in the park position.
  6. Release the brake pedal.

Did the backup lamps operate properly?

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

Go to Step 3

3

  1. Install a scan tool.
  2. Turn ON the ignition, with the engine OFF.
  3. With the scan tool, command the Perimeter Lighting ON and OFF from the remote function actuation Output Control data list.

Does the PERIM LP relay turn ON and OFF with each command?

Go to Step 6

Go to Step 4

4

  1. Turn OFF the ignition.
  2. Disconnect the PERIM LP relay. Refer to Relay Replacement in Wiring Systems.
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the PERIM LP relay supply voltage circuit with a test lamp that is connected to ground.

Does the test lamp illuminate?

Go to Step 5

Go to Step 14

5

  1. Turn OFF the ignition.
  2. Connect a test lamp between the PERIM LP relay supply voltage circuit and the PERIM LP relay exterior courtesy lamps relay control circuit.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, command the PERIM LP relay ON and OFF.

Does the test lamp turn ON and OFF with each command?

Go to Step 12

Go to Step 9

6

At the PERIM LP relay, probe the PERIM LP relay switched supply voltage circuit with a test lamp that is connected to ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 15

7

Connect a 10-amp fused jumper between the PERIM LP relay switched supply voltage circuit and the B/U LP fuse supply voltage circuit.

Do the backup lamps illuminate?

Go to Step 12

Go to Step 8

8

  1. Turn OFF the ignition.
  2. Remove the inoperative backup lamp bulb.
  3. Connect a test lamp between the backup lamp supply voltage circuit and the backup lamp ground circuit.
  4. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 11

Go to Step 10

9

Test the PERIM LP relay exterior courtesy lamps relay control circuit for an open circuit or a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 13

10

Test the backup lamp supply voltage circuit for a high resistance, short to ground or an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 16

11

Inspect for poor connections at the backup lamp bulb. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 17

12

Inspect for poor connections at the PERIM LP relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 18

13

Inspect for poor connections at the harness connector of the remote control door lock receiver module (RCDLR). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 20

Go to Step 19

14

Replace the fuse block-I/P. Refer to Instrument Panel Electrical Center or Junction Block Replacement in Wiring Systems.

Did you complete the replacement?

Go to Step 20

--

15

Repair the open in the PERIM LP relay switched supply voltage circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 20

--

16

Repair the open circuit in the backup lamp ground circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you complete the repair?

Go to Step 20

--

17

Replace the backup lamp bulb.

Did you complete the replacement?

Go to Step 20

--

18

Replace the PERIM LP relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the replacement?

Go to Step 20

--

19

Replace the RCDLR module. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

Go to Step 20

--

20

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2