GM Service Manual Online
For 1990-2009 cars only

Diagnostic Aids

Before performing this procedure, ensure that the following conditions are met:

    • The vehicle park brake is SET.
    • The rear parking assist (RPA) disable switch is ON.

Step

Action

Value(s)

Yes

No

Schematic Reference: Rear Parking Assist Schematics

1

Did you review the operation and perform the necessary inspections?

--

Go to Step 2

Go to Symptoms - Ultrasonic Rear Parking Assist

2

  1. Turn the ignition ON.
  2. Place foot on the BRAKE.
  3. Shift the vehicle into REVERSE.

Do all of the three display indicators illuminate for 2 seconds and then turn off?

--

Go to Step 3

Go to Step 4

3

  1. Shift the vehicle into PARK.
  2. Turn the ignition OFF.
  3. Turn the RPA switch to the OFF position.
  4. Turn the ignition ON.
  5. Place foot on the BRAKE.
  6. Shift the vehicle into REVERSE.

Do all three display indicators illuminate for 2 seconds and then turn off?

--

Go to Step 14

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

4

Does the red indicator flash?

--

Go to Rear Parking Assist Inoperative - Red Indicator Flashes

Go to Step 5

5

Do all of the indicators but one indicator illuminate?

--

Go to Step 7

Go to Step 6

6

Does any indicator remain on?

--

Go to Step 8

Go to Step 11

7

Connect a test lamp between the control circuit of the inoperative indicator at the module connector and a good ground.

Does the test lamp illuminate?

--

Go to Step 21

Go to Step 9

8

  1. Turn the ignition OFF.
  2. Disconnect the rear parking assist display.
  3. Turn the ignition ON.
  4. Connect a test lamp between the rear parking assist display supply voltage circuit and the malfunctioning indicator control circuit.

Does the test lamp illuminate?

--

Go to Step 10

Go to Step 20

9

Test the control circuit of the inoperative indicator for an open, a short to battery voltage or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 20

10

Test the control circuit of the inoperative indicator for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 21

11

Test the rear object sensor control module ground circuit for an open. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 12

12

Test the rear object sensor control module ignition 1 voltage circuit for an open and for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 13

13

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

Did you find and correct the condition?

--

Go to Step 26

Go to Step 16

14

  1. Turn the ignition OFF.
  2. Disconnect the RPA switch.
  3. Connect a 3 amp fused jumper wire between the RPA switch signal circuit and a good ground.
  4. Turn the ignition ON.
  5. Place foot on BRAKE.
  6. Shift the vehicle into REVERSE.

Do all of the three display indicators illuminate for 2 seconds and then turn off?

--

Go to Step 15

Go to Step 22

15

Test the RPA switch signal circuit for an open or for a high resistance. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 21

16

  1. Turn the ignition OFF.
  2. Disconnect the RPA switch.
  3. Turn the ignition ON.
  4. Place foot on BRAKE.
  5. Shift the vehicle into REVERSE.

Do all of the three display indicators illuminate for 2 seconds and then turn off?

--

Go to Step 22

Go to Step 17

17

Test the RPA switch signal circuit for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 18

18

  1. Turn the ignition OFF.
  2. Disconnect the rear parking assist display.
  3. Turn the ignition ON.
  4. Connect a test lamp between the rear parking assist display supply voltage circuit and a good ground.

Does the test lamp illuminate?

--

Go to Step 20

Go to Step 19

19

Test the rear parking assist display supply voltage circuit for an open and for a short to ground. Refer to Circuit Testing and to Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 21

20

Inspect for poor connections at the harness connector of the rear parking assist display. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 24

21

Inspect for poor connections at the harness connector of the rear object sensor control module. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 25

22

Inspect for poor connections at the harness connector of the RPA switch. Refer to Testing for Intermittent Conditions and Poor Connections and to Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 26

Go to Step 23

23

Replace the RPA switch. Refer to Interior Lamp and Multifunction Switch Replacement in Doors.

Did you complete the replacement?

--

Go to Step 26

--

24

Replace the rear parking assist display. Refer to Information Center Telltale Assembly Replacement .

Did you complete the replacement?

--

Go to Step 26

--

25

Replace the rear object sensor control module. Refer to Object Alarm Module Replacement .

Did you complete the replacement?

--

Go to Step 26

--

26

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2