GM Service Manual Online
For 1990-2009 cars only

Entering Self-Diagnostic Information

This vehicle is equipped with a on-board diagnostic display feature capable of displaying encoded messages using the 3 indicators on the rear parking assist display. After the bulb check has been completed, the red (outside) indicator will flash if there is a problem with the system. The module disables operation of the Ultrasonic Rear Parking Assist (URPA) system under this condition. In order to enter the diagnostic mode, you must complete the following actions:

  1. Short the rear parking assist diagnostic connector to ground while vehicle is in PARK.
  2. Turn the ignition ON.
  3. Put the vehicle in REVERSE within 5 seconds.

When the diagnostic mode is first entered, the rear parking assist display, will flash the amber (outside) indicator and the red (outside) indicator. After entering the diagnostic mode, the indicators on the rear parking assist display will flash one or more of the encoded messages in the table below to indicate where the fault exists within the URPA system. The specific steps to clear the encoded messages are provided below.

Clearing Self-Diagnostic Information

The URPA encoded messages may be cleared in one of the following ways:

Driving the Vehicle

  1. The rear parking assist diagnostic connector must be not grounded in order to clear the stored messages.
  2. Drive the vehicle forward at least 24 km/hr (15 mph).
  3. Stop the vehicle.
  4. Turn OFF the ignition.

Vehicle Stopped

  1. The rear parking assist diagnostic connector must be not grounded in order to clear the stored messages.
  2. Turn ON the ignition, then shift into REVERSE within five seconds.
  3. Turn OFF the ignition.

Diagnostic Indicators

#

State

Amber (Outside)

Amber (Middle)

Red (Outside)

Flashing

1

Start of Diagnostics

X

--

X

--

2

Object Sensor Control Module and Wiring

X

X

X

--

3

RR Corner Object Sensor and Wiring

X

--

--

--

4

RR Middle Object Sensor and Wiring

X

X

--

--

5

LR Middle Object Sensor and Wiring

--

X

X

--

6

LR Corner Object Sensor and Wiring

--

--

X

--

7

Chime Warning Wiring

--

X

--

--

8

Reverse Input Wiring

--

X

--

X

Chimes 4 times

9

Display, Wiring, or Module

--

--

--

--

10

Supply Voltage to Sensor

X

X

X

X

Flashes in the following sequence:

  1. Amber (Outside)
  2. Amber (Outside) and Amber (Middle)
  3. Amber (Middle) and Red (Outside)
  4. Red (Outside)

11

Supply Voltage to Sensor

X

X

X

--

12

Low Reference to Sensor

X

X

X

X

Flashes in the following sequence:

  1. Amber (Outside)
  2. Amber (Outside) and Amber (Middle)
  3. Amber (Middle) and Red (Outside)
  4. Red (Outside)

13

Low Reference to Sensor

X

X

X

--