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For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2005 🢒 CTS 🢒 Body 🢒 Stationary Windows 🢒 Backup Lamps Inoperative

Backup Lamps Inoperative Automatic Transmission

Test Description

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

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

    2.

  2. This step tests for voltage at the control side of the reverse relay.

    3.

  3. This step verifies that the control module is providing ground to the reverse relay.

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Master Electrical Component List

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

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

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 Reverse Lamp Relay ON and OFF from the rear integration module (RIM) Output Control data list.

Does the reverse lamp 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 reverse relay. Refer to Relay Replacement .
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the reverse relay control side supply voltage circuit with a test lamp that is connected to a good 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 reverse relay control side supply voltage circuit and the reverse lamp relay control circuit.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, command the Reverse Lamp Relay ON and OFF.

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

Go to Step 12

Go to Step 9

6

Probe the reverse relay switch side supply voltage circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 15

7

Connect a 10-amp fused jumper between the reverse relay switch side supply voltage circuit and the backup lamp supply voltage circuit.

Do both of 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 reverse lamp relay control circuit for an open or a short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs .

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 or an open. Refer to Circuit Testing and Wiring Repairs .

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 .

Did you find and correct the condition?

Go to Step 20

Go to Step 18

12

Inspect for poor connections at the reverse relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 20

Go to Step 17

13

Inspect for poor connections at the harness connector of the RIM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 20

Go to Step 19

14

Repair the open circuit in the reverse relay control side supply voltage circuit. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 20

--

15

Repair the open circuit in the reverse relay switch side supply voltage circuit. Refer to Circuit Testing and Wiring Repairs .

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 .

Did you complete the repair?

Go to Step 20

--

17

Replace the reverse relay. Refer to Relay Replacement .

Did you complete the replacement?

Go to Step 20

--

18

Replace the backup lamp bulb.

Did you complete the replacement?

Go to Step 20

--

19

Replace the RIM. Refer to Control Module References 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

Backup Lamps Inoperative Manual Transmission

Test Description

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

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

    2.

  2. This step tests for voltage at the control side of the reverse relay.

    3.

  3. This step verifies that the control module is providing ground to the reverse relay.

Step

Action

Yes

No

Schematic Reference: Exterior Lights Schematics

Connector End View Reference: Master Electrical Component List

1

Did you perform the Diagnostic System Check - Vehicle?

Go to Step 2

Go to Diagnostic System Check - Vehicle

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

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 reverse lamp relay ON and OFF from the rear integration module (RIM) Output Control data list.

Does the reverse lamp 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 reverse relay. Refer to Relay Replacement .
  3. Turn ON the ignition, with the engine OFF.
  4. Probe the reverse relay control side supply voltage circuit with a test lamp that is connected to a good 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 reverse relay control side supply voltage circuit and the reverse lamp relay control circuit.
  3. Turn ON the ignition, with the engine OFF.
  4. With a scan tool, command the reverse lamp relay ON and OFF.

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

Go to Step 15

Go to Step 9

6

Probe the reverse relay switch side supply voltage circuit with a test lamp that is connected to a good ground.

Does the test lamp illuminate?

Go to Step 7

Go to Step 19

7

Connect a 10-amp fused jumper between the reverse relay switch side supply voltage circuit and the backup lamp supply voltage circuit.

Do both of the backup lamps illuminate?

Go to Step 15

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 14

Go to Step 11

9

Test the reverse lamp relay control circuit for an open or a short to voltage. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 25

Go to Step 10

10
  1. Turn OFF the ignition.
  2. Disconnect the reverse switch.
  3. Connect the 3-amp fused jumper wire between the reverse switch signal circuit of the reverse switch and the ground circuit of the reverse switch.
  4. Turn ON the ignition, with the engine OFF.

Do the backup lamps illuminate?

Go to Step 16

Go to Step 12

11

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

Did you find and correct the condition?

Go to Step 25

Go to Step 20

12

Test for an open or a short to voltage in the reverse switch signal circuit of the reverse switch. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 25

Go to Step 13

13

Test for an open in the ground circuit of the reverse switch. Refer to Circuit Testing and Wiring Repairs .

Did you find and correct the condition?

Go to Step 25

Go to Step 17

14

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

Did you find and correct the condition?

Go to Step 25

Go to Step 22

15

Inspect for poor connections at the reverse relay. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 25

Go to Step 21

16

Inspect for poor connections at the reverse lamp switch harness connector. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 25

Go to Step 23

17

Inspect for poor connections at the harness connector of the RIM. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs .

Did you find and correct the condition?

Go to Step 25

Go to Step 24

18

Repair the open circuit in the reverse relay control side supply voltage circuit. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 25

--

19

Repair the open circuit in the reverse relay switch side supply voltage circuit. Refer to Circuit Testing and Wiring Repairs .

Did you complete the repair?

Go to Step 25

--

20

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

Did you complete the repair?

Go to Step 25

--

21

Replace the reverse relay. Refer to Relay Replacement .

Did you complete the replacement?

Go to Step 25

--

22

Replace the backup lamp bulb.

Did you complete the replacement?

Go to Step 25

--

23

Replace the reverse lamp switch. Refer to Backup Lamp Switch Replacement for the Aisin AY6 transmission or Backup Lamp Switch Replacement for the Tremec 6-Speed transmission.

Did you complete the replacement?

Go to Step 25

--

24

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

Did you complete the replacement?

Go to Step 25

--

25

Operate the system in order to verify the repair.

Did you correct the condition?

System OK

Go to Step 2