GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Chevrolet 🢒 2005 🢒 Corvette 🢒 Body 🢒 Lighting Systems 🢒 Backup Lamps Always On

Backup Lamps Always On Automatic Transmission

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. Observe the backup lamps.
  4. Shift the gear selector to the REVERSE position and then to the PARK position.

Do 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. Verify that the vehicle is in the PARK position.
  3. Turn ON the ignition, with the engine OFF.
  4. With the scan tool, observe the Backup Lamp Relay Cmd. parameter in the body control module (BCM) lighting data list.

Does the scan tool indicate the Backup Lamp Relay Cmd. is OFF?

Go to Step 4

Go to Step 9

4
  1. Turn OFF the ignition.
  2. Disconnect the reverse lamp relay. Refer to Relay Replacement in Wiring Systems.
  3. Verify that the vehicle is in the PARK position.
  4. Turn ON the ignition, with the engine OFF.

Do the backup lamps turn OFF?

Go to Step 6

Go to Step 5

5

Locate and repair a short to battery voltage in the backup lamps voltage supply circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 11

Go to Step 9

6
  1. Turn OFF the ignition.
  2. Connect a test lamp between the reverse lamp relay control side voltage supply circuit and the backup lamp relay control circuit.
  3. Verify that the vehicle is in the PARK position.
  4. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 9

Go to Step 7

7

Inspect for poor connections at the reverse lamp 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 11

Go to Step 8

8

Replace the reverse lamp relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the repair?

Go to Step 11

--

9

Inspect for poor connections at the harness connector of the BCM. 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 11

Go to Step 10

10

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

Did you complete the replacement?

Go to Step 11

--

11

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2

Backup Lamps Always On Manual Transmission

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. Observe the backup lamps.
  4. Shift the gear selector to the REVERSE position and then to the NEUTRAL position.

Do 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. Apply the park brake.
  3. Place the vehicle in the NEUTRAL position.
  4. Turn ON the ignition, with the engine OFF.
  5. With the scan tool, observe the Backup Lamp Relay Cmd. parameter in the body control module (BCM) lighting data list.

Does the scan tool indicate the Backup Lamp Relay Cmd. is OFF?

Go to Step 4

Go to Step 9

4
  1. Turn OFF the ignition.
  2. Disconnect the reverse lamp relay. Refer to Relay Replacement in Wiring Systems.
  3. Apply the park brake.
  4. Place the vehicle in the NEUTRAL position.
  5. Turn ON the ignition, with the engine OFF.

Do the backup lamps turn OFF?

Go to Step 6

Go to Step 5

5

Locate and repair a short to battery voltage in the backup lamps voltage supply circuit. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 12

6
  1. Turn OFF the ignition.
  2. Connect a test lamp between the reverse lamp relay control side voltage supply circuit and the backup lamp relay control circuit.
  3. Verify that the vehicle is in the NEUTRAL position.
  4. Turn ON the ignition, with the engine OFF.

Does the test lamp illuminate?

Go to Step 12

Go to Step 7

7

Inspect for poor connections at the reverse lamp 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 15

Go to Step 8

8

Replace the reverse lamp relay. Refer to Relay Replacement in Wiring Systems.

Did you complete the repair?

Go to Step 15

--

9
  1. Turn OFF the ignition.
  2. Disconnect the reverse switch. Refer to Backup Lamp Switch Replacement in Manual Transmission - Tremec 6-Speed.
  3. Turn ON the ignition, with the engine OFF.

Do the backup lamps turn OFF?

Go to Step 11

Go to Step 10

10

Test the reverse lamp relay control circuit for a short to battery voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

Go to Step 15

Go to Step 12

11

Inspect for poor connections at the harness connector of the reverse switch. 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 15

Go to Step 13

12

Inspect for poor connections at the harness connector of the BCM. 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 15

Go to Step 14

13

Replace the reverse switch. Refer to Backup Lamp Switch Replacement in Manual Transmission - Tremec 6-Speed.

Did you complete the repair?

Go to Step 15

--

14

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

Did you complete the replacement?

Go to Step 15

--

15

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2