For 1990-2009 cars

### 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: Object Detection Connector End Views or Component Connector End Views
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 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