aid that alerts the driver to obstacles which are
located immediately behind the vehicle. Objects are
sensed using ultrasonic sound waves. When an object
is detected, the system will give the driver visual and
audible warnings. The system is customer program-
mable through the Electronic Vehicle Information
Center (EVIC) but will be enabled from the factory
as a default.

The major components of the park assist system

are:

• Park Assist Module - supplies voltage to the

object detection sensors and park assist display. It
triggers the sensors, analyzes the echo delay times
and calculates obstacle distances. It sends display
information to the park assist display, performs sys-
tem diagnostics, and communicates via the Program-
mable

Communication

Interface

(PCI)

date

bus

network.

• Park Assist Sensors - there are four sensors

located in the rear bumper that generate ultrasonic
pulses when triggered by the park assist module. The
sensors signal the park assist module when reflected
ultrasonic pulses are received.

• Park Assist Display - there are sixteen Light

Emitting Diode (LED) indicators which provide indi-
cation of relative distance to obstacles. When the sys-
tem is engaged and no obstacles are detected, the
two outermost yellow LED’s are lit at reduced bright-
ness to show the system is working. As the distance
to a detected obstacle decreases, more yellow LED’s
towards the center of the display illuminate.

For diagnosis and testing of the park assist sys-

tem, use a scan tool and the appropriate body diag-
nostic information.

OPERATION

Refer to the proper Body Diagnostic Procedures

manual for complete chime/buzzer operation and con-
ditions for operation.

CHIME/BUZZER

8B - 1

HIGH SPEED WARNING - EXPORT

When the vehicle speed sensor sees 120 ± 3 Km/h

(75 ± 2 mph), it sends a PCI data bus message to the
Body Control Module (BCM). The BCM then turns on
the chime to let the driver know that the vehicle has
reached a speed greater than 120 ± 3 Km/h (75 ± 2
mph). This audible message will continue until the
vehicle is slowed below the predetermined speed.

PARK ASSIST SYSTEM

The Park Assist System display activates an audi-

ble tone that changes from intermittent to continu-
ous as the final two Light Emitting Diodes (LED’s)
are illuminated on one side or both sides of the dis-
play.

The system detection length from the rear of the

vehicle is 0.3 meters to 1.5 meters. This area extends
around the rear side of the vehicle. The system detec-
tion height from the ground is 0.2 meters to about
1.5 meters. The radio mutes when the system acti-
vates its audible tone.

When the driver selects Reverse the system scans

for objects behind the vehicle using four sensors
located in the rear bumper. A warning display above
the rear window provides both visible and audible
warnings indicating the range of the object.

The system is active only when the transmission

gear selector is in reverse for vehicle speeds less than
16 Km/h (10 mph). If the vehicle’s Parking/Emer-
gency Brake is applied, the system is deactivated.

The display contains two sets of yellow and red

Light Emitting Diode’s (LED’s) that the driver can
see as they look over their shoulder while backing
up. Each side of the vehicle has its own warning
LED’s. The system provides a visual warning by illu-
minating one or more yellow LED’s as the vehicle
gets closer to the object. As the vehicle continues to
approach the object, one red LED is illuminated and
the system emits a series of short beeps. The tone
will remain constant and both red LED’s are illumi-
nated once the vehicle is within 12 inches (30.5 cm)
of the object.

The system can be turned ON or OFF through the

Electronic Vehicle Information Center (EVIC) when
the vehicle is in PARK. If the park assist system is
turned OFF, a single chime will sound and the EVIC
will display the following message “REAR PARK
ASSIST OFF”, when the vehicle is in reverse.

• Ensure that the rear bumper is free of dirt and

debris to keep the system operating properly.

• Jackhammers, large trucks, and other vibrations

could affect the performance of the system.

• Ensure that the parking brake is not applied.
If “Service Park Assist System” appears in the

EVIC after making sure the rear bumper is clean,

proceed to diagnose the system using a scan tool and
the appropriate diagnostic information.

WARNING

On vehicles equipped with airbags, disable

the airbag system before attempting any steer-
ing

wheel,

steering

column,

instrument

panel component diagnosis or service. Discon-
nect and isolate the battery negative (ground)
cable, then wait two minutes for the airbag sys-
tem capacitor to discharge before performing
further diagnosis or service. This is the only
sure way to disable the airbag system. Failure
to take the proper precautions could result in
accidental airbag deployment, personal injury,
or death.

DIAGNOSIS AND TESTING - CHIME SYSTEM

Refer to the proper Body Diagnostic Procedures

manual for complete Diagnosis and Testing of the
Chime System.

NO TONE WHEN IGNITION SWITCH IS TURNED ON
AND DRIVER’S SEAT BELT IS NOT BUCKLED.

(1) Using a DRB lll

t scan tool, actuate chime

(BCM actuates).

(2) Using a voltmeter, check for voltage:

(a) BCM has two battery feeds at pin 1 and pin

5 of the 6–way connector.

(b) Pin 5 of the (BX2) 32 way connector of the

BCM for ignition feed.

(c) Check voltage (PX2) connector, pin 34 for 12v.
(d) If voltage OK, go to step Step 3
(e) If NO voltage repair as necessary. Refer to

the appropriate wiring information. The wiring
information includes wiring diagrams, proper wire
and connector repair procedures, further details on
wire harness routing and retention, as well as pin-
out and location views for the various wire harness
connectors, splices and grounds.
(3) Check drivers seat belt buckle switch input

(from Occupant Restraint Controller (ORC) for a
closed circuit when not buckled. If input not seen,
look for open in wiring or switch. The switch is
grounded when belt is not buckled.

(4) Verify Programmable Communication Interface

(PCI) data bus communication between ORC and
BCM.

NO FASTEN SEAT BELT LAMP WHEN IGNITION
SWITCH IS TURNED ON.

(1) Check for burned out lamp.
(2) Using a voltmeter check for voltage at the clus-

ter connector:

(a) Pin 2 of the mechanical instrument cluster

for battery feed.

8B - 2

CHIME/BUZZER

CHIME/BUZZER (Continued)

(b) Pin 11 of the mechanical instrument cluster

for ignition voltage.
(3) Repair as necessary.

FASTEN SEAT BELT LAMP OR TONE CONTINUES
FOR MORE THAN 10 SECONDS AFTER SEAT
BELTS ARE FASTENED AND DRIVER’S DOOR IS
CLOSED.

Refer to the proper Body Diagnostic Procedures

manual.

NO TONE WHEN PARK OR HEADLAMPS ARE ON
AND DRIVER’S DOOR IS OPEN.

Make sure ignition is in lock position with the key

removed.

(1) Check the BCM DTC’s and BCM sensors to

verify the door is open. Repair as necessary.

(2) Actuate Chime (BCM actuates).
(3) Inspect BCM connectors and wires for proper

connection.

(4) Measure with a voltmeter the voltage (12v) on

BCM connector (PX2) pin 34 with harness connected.

(5) Check BCM sensors to verify headlamp switch

position.

PARK ASSIST DISPLAY

DESCRIPTION

The Park Assist Display (Fig. 1) is located in the

rear of vehicle, over the rear window in the headliner
(Fig. 2). It is a molded plastic unit housing Light
Emitting

Diodes

(LED’s)

and

chime

module.

Located in the rear of the vehicle for easy visual ref-
erence when the driver is backing up.

The display is used to alert the driver of any obsta-

cles detected in the rear of the vehicle. The chime or
audible signal also comes from the display unit.

OPERATION

When the ignition is put in the RUN position, all

the Light Emitting Diodes (LED’s) will illuminate for
approximately one second. This will be interrupted if
the system senses an obstacle.

The ready status will be sensed by the outermost

two yellow LED’s being illuminated at 50% intensity.
As the obstacle is sensed, the yellow LED’s will start
illuminating inward until the object in approximately
40 cm (16 in.) away and then the inner red LED will
light.

The display is sensitive to which side of the rear of

the vehicle that the object is detected. If on the left
rear, the left segments will light and the same for the
right side of the vehicle.

Fig. 1 PARK ASSIST DISPLAY

Fig. 2 PARK ASSIST DISPLAY LOCATION

CHIME/BUZZER

8B - 3

CHIME/BUZZER (Continued)

CORRELATION OF LED SEGMENTS TO DISTANCE

DISPLAY LED

DISTANCE

LED COLOR

AUDIBLE SIGNAL

REAR CORNERS

REAR CENTER

1st LED

150 cm (59 in.)

Yellow

None

2nd LED

120 cm (47 in.)

Yellow

None

3rd LED

100 cm (39 in.)

Yellow

None

4th LED

80 cm (31.5 in.)

Yellow

None

5th LED

65 cm (25.5 in.)

Yellow

None

6th LED

50 cm (20 in.)

Yellow

None

7th LED

40 cm (16 in.)

Red

40 cm (16 in.)
Intermittant

8th LED

15 cm (6 in.)

30 cm (12 in.)

Red

30 cm (12 in.)
Continuous

There will be an audible tone when the object gets

within 40 cm (16 in.) from the rear of the vehicle.

To diagnose and test the Park Assist System, use a

scan tool and the appropriate diagnostic information.

REMOVAL

(1) Open hood.
(2) Disconnect and isolate the battery negative

cable.

(3) Open liftgate.
(4) Lower the headliner in the rear of the vehicle

in the liftgate opening. Follow the headliner removal
procedure for the rear of the headliner (Refer to 23 -
BODY/INTERIOR/HEADLINER - REMOVAL).

(5) Bend the retaining tabs upwards to allow the

park assist display to drop out of the headliner open-
ing (Fig. 3).

(6) Disconnect the display electrical connector (Fig.

3) and remove from vehicle.

INSTALLATION

(1) Position the Park Assist Display in headliner

opeing and connect the display electrical connector
(Fig. 3).

(2) Bend the retaining tabs down behind the head-

liner (Fig. 3).

(3) Raise the headliner in the rear of the vehicle in

the liftgate opening (Refer to 23 - BODY/INTERIOR/
HEADLINER - INSTALLATION).

(4) Close liftgate.
(5) Connect the battery negative cable.
(6) Close hood.
(7) Verify vehicle and system operation.

PARK ASSIST MODULE

DESCRIPTION

The Park Assist Module (Fig. 4) is located on the

left side of the vehicle, behind the quarter trim
panel, just behind the C-pillar (Fig. 5). It is has a
molded plastic housing which housing internal cir-
cuitry and one electrical connector. There are two
mounting tabs that affix the module to the left inner
quarter panel with two screws.

The module has a number of functions:
• Supply voltage to the sensors and display.

• Disconnection of the display with bus idle and

over voltage Vmax.

• Triggering the sensors.

• Analyze echo delay times and calculate obstacle

distances.

• Bi-directional data communication to the display

for diagnosis.

• System diagnostics - diagnosis and error han-

dling (sensors, display, module).

• Data exchange over the Programmable Commu-

nication Interface (PCI) data bus.

Fig. 3 PARK ASSIST DISPLAY - REMOVE/INSTALL

1 - PARK ASSIST DISPLAY
2 - DISPLAY RETAINING TABS
3 - HEADLINER
4 - DISPLAY ELECTRICAL CONNECTOR

8B - 4

CHIME/BUZZER

PARK ASSIST DISPLAY (Continued)

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