GM Service Manual Online
For 1990-2009 cars only

Diagnostic Aids

Before performing this procedure, ensure that the vehicle park brake is SET.

Step

Action

Value(s)

Yes

No

Schematic Reference: Object Detection Schematics

Connector End View Reference: Component Connector End Views

1

Did you review the operation and perform the necessary inspections?

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Go to Step 2

Go to Symptoms - Ultrasonic Rear Parking Assist

2

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

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

--

Go to Testing for Intermittent Conditions and Poor Connections

Go to Step 3

3

Does the red indicator flash?

--

Go to Rear Parking Assist Inoperative - Red Indicator Flashes

Go to Step 4

4

Do all of the indicators but one indicator illuminate?

--

Go to Step 6

Go to Step 5

5

Does any indicator remain on?

--

Go to Step 7

Go to Step 10

6

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 16

Go to Step 8

7

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

Does the indicator illuminate?

--

Go to Step 9

Go to Step 15

8

Test the control circuit of the inoperative indicator for a short to battery voltage and a high resistance.

Refer to Circuit Testing and to Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 19

Go to Step 15

9

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

Did you find and correct the condition?

--

Go to Step 19

Go to Step 16

10

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

Did you find and correct the condition?

--

Go to Step 19

Go to Step 11

11

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 Wiring Repairs.

Did you find and correct the condition?

--

Go to Step 19

Go to Step 12

12

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

Did you find and correct the condition?

--

Go to Step 19

Go to Step 13

13

  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 19

Go to Step 14

14

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

Did you find and correct the condition?

--

Go to Step 19

Go to Step 16

15

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

Did you find and correct the condition?

--

Go to Step 19

Go to Step 17

16

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 Connector Repairs.

Did you find and correct the condition?

--

Go to Step 19

Go to Step 18

17

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

Did you complete the replacement?

--

Go to Step 19

--

18

Replace the rear object sensor control module. Refer to Control Module References for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 19

--

19

Operate the system in order to verify the repair.

Did you correct the condition?

--

System OK

Go to Step 2