Contents Wiring diagrams Section: Collision/avoidance All sections

Object Detection System Buick LaCrosse I

Collision/avoidance 6 illustrations ~1752 words

Fastener Tightening Specifications

ApplicationSpecification
MetricEnglish
Rear Parking Assist Receiver2 N.m18 lb in

Fastener Tightening Specifications

Scheme 1

Scheme 1: Object Detection Schematics

Scheme 2

Scheme 2: Object Detection Component Views
CalloutComponent Name
1Reading Lamps - Overhead Console
2Garage Door Opener
3Dome/Reading Lamp - Left
4Rear Park Assist (RPA) Display
5Dome/Reading Lamp - Right

Scheme 3

Scheme 3
CalloutComponent Name
1Audio Amplifier
2Remote Control Door Lock Receiver (RCDLR)
3Navigation Antenna
4Rear Window Shelf
5Rear Parking Assist (RPA) Module
6Electronic Compass Module
7Rear Compartment Courtesy Lamp

Scheme 4

Scheme 4
CalloutComponent Name
1Rear Parking Assist (RPA) Diagnostic Connector

Scheme 5

Scheme 5
CalloutComponent Name
1Rear Window Defogger Grid
2Center High Mounted Stop Lamp (CHMSL)
3Backup Lamp - Right
4Tail Lamp - Right Upper
5Tail/Stop and Turn Signal Lamp - Right
6Marker Lamp - Right
7Tail Lamp - Right Lower
8Object Sensor - RR Corner
9Object Sensor - RR Middle
10License Lamp - Right
11License Lamp - Left
12Object Sensor - LR Middle
13Object Sensor - LR Corner
14Tail Lamp - Left Lower
15Marker Lamp - Left
16Tail/Stop and Turn Signal Lamp - Left
17Backup Lamp - Left
18Tail Lamp - Left Upper

Object Detection Connector End Views

Object Sensor - LR Corner Connector Part Information OEM: 15324398 (Delphi) 1-967642-1 (Tyco) Service: 15306313 3-Way F MQS Sealed (BK) Pin Wire Color Circuit No. Function 1 YE 2375 LR Corner Object Sensor Signal 2 GY 2379 Object Sensor Low Reference 3 D-BU 2374 Object Sensor Supply Voltage

Object Sensor - LR Middle Connector Part Information OEM: 15324398 (Delphi) 1-967642-1 (Tyco) Service: 15306313 3-Way F MQS Sealed (BK) Pin Wire Color Circuit No. Function 1 OG 2376 LR Middle Object Sensor Signal 2 GY 2379 Object Sensor Low Reference 3 D-BU 2374 Object Sensor Supply Voltage

Object Sensor - RR Corner Connector Part Information OEM: 15324398 (Delphi) 1-967642-1 (Tyco) Service: 15306313 3-Way F MQS Sealed (BK) Pin Wire Color Circuit No. Function 1 RD 2378 RR Corner Object Sensor Signal 2 GY 2379 Object Sensor Low Reference 3 D-BU 2374 Object Sensor Supply Voltage

Object Sensor - RR Middle Connector Part Information OEM: 15324398 (Delphi) 1-967642-1 (Tyco) Service: 15306313 3-Way F MQS Sealed (BK) Pin Wire Color Circuit No. Function 1 D-GN 2377 RR Middle Object Sensor Signal 2 GY 2379 Object Sensor Low Reference 3 D-BU 2374 Object Sensor Supply Voltage

Rear Object Sensor Control Module Connector Part Information OEM: 12124957 (Delphi) 927690-1 (AMP) Service: 88987946 26-Way F Modu IV Series (BK) Pin Wire Color Circuit No. Function 1 YE 2375 LR Corner Object Sensor Signal 2 OG 2376 LR Middle Object Sensor Signal 3 D-GN 2377 RR Middle Object Sensor Signal 4 RD 2378 RR Corner Object Sensor Signal 5 D-BU 2374 Object Sensor Supply Voltage 6 GY 2379 Object Sensor Low Reference 7-11 - - Not Used 12 BK 550 Ground 13 PK 739 Ignition 1 Voltage 14 - - Not Used 15 L-GN 24 Backup Lamp Supply Voltage 16 L-GN 2525 Rear Parking Assist Diagnostic Signal 17 - - Not Used 18 D-GN 389 Vehicle Speed Signal 19-21 - - Not Used 22 L-GN 1845 Chime Control 23 WH 2370 Telltale Assembly Supply Voltage 24 GY 2373 Red Indicator Control 25 D-BU 2372 Center Amber Indicator Control 26 OG 2371 Left Amber Indicator Control

Rear Parking Assist (RPA) Display Connector Part Information OEM: 12045813 Service: 12101889 4-Way F Metri-Pack 150 Series (NA) Pin Wire Color Circuit No. Function A WH 2370 Telltale Assembly Supply Voltage B OG 2371 Left Amber Indicator Control C D-BU 2372 Center Amber Indicator Control D GY 2373 Red Indicator Control

Rear Parking Assist (RPA) Diagnostic Connector Connector Part Information OEM: 12047682 Service: 12101850 1-Way F Metri-Pack 150 Series (BK) Pin Wire Color Circuit No. Function A 2525 L-GN Rear Parking Assist Diagnostic Input

Diagnostic Starting Point - Object Detection

Begin the system diagnosis by reviewing the system Description and Operation, refer to Object Detection Description and Operation . Reviewing the Description and Operation information will help you determine the correct symptom diagnostic procedure when a malfunction exists. Reviewing the Description and Operation information will also help you determine if the condition described by the customer is normal operation. Refer to Symptoms - Object Detection in order to identify the correct procedure for diagnosing the system and where the procedure is located.

Diagnostic Trouble Code (DTC) Displaying

This vehicle is equipped with an on-board diagnostic display feature capable of displaying DTCs using the 3 indicators on the rear parking assist display. After the bulb check has been completed, the red outside indicator flashes to indicate a malfunction 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, complete the following actions

  1. With the ignition turned OFF, short the rear parking assist diagnostic connector to ground while the vehicle is in PARK. Refer to «Object Detection Component Views»(/buick/lacrosse/i-2004-2009/remont/collisionavoidance/#object-detection-system) for the location of the rear parking assist diagnostic connector.
  2. Turn the ignition ON.
  3. Place your foot on the brake.
  4. Shift the vehicle into REVERSE within 5 seconds. If the vehicle is not shifted into reverse within 5 seconds after turning the ignition ON, the diagnostic mode will still be initiated. However, a reverse input wiring fault will be registered as sequence #7 as shown in the Diagnostic Indicator table below. Refer to «Diagnostic Trouble Code (DTC) Clearing»(/buick/lacrosse/i-2004-2009/remont/collisionavoidance/#object-detection-system__diagnostic-trouble-code-dtc-clearing) for specific steps on how to clear DTCs. After the reverse input wiring code is cleared, repeat the DTC displaying steps in order to enter the diagnostic mode.

When the diagnostic mode is first entered, the rear parking assist display displays the amber outside indicator and the red outside indicator. Then the indicators on the rear parking assist display will display one or more of the sequences in the table below to indicate where the fault exists within the rear parking assist system. Refer to Diagnostic Trouble Code (DTC) Clearing for the specific steps on how to clear diagnostic trouble codes.

#State/Fault LocationAmber OutsideAmber MiddleRed OutsideFlashing
1Start of DiagnosticsXX
2RR Corner Object Sensor and WiringX
3RR Middle Object Sensor and WiringXX
4LR Middle Object Sensor and WiringXX
5LR Corner Object Sensor and WiringX
6Chime Warning WiringX
7Reverse Input WiringXX
8IMPORTANT: This diagnostic pattern sets for an open sensor supply voltage circuit and sensor low reference circuit. Sensor Supply Voltage Circuit and Sensor Low Reference CircuitXXXX Flashes in the following sequence: Amber Outside Amber Outside and Amber Middle Amber Middle and Red Outside Red Outside
9IMPORTANT: This diagnostic pattern sets for a short to ground in the sensor supply voltage circuit. Sensor Supply Voltage CircuitXXX
IMPORTANT
This diagnostic pattern sets for an open sensor supply voltage circuit and sensor low reference circuit.
IMPORTANT
This diagnostic pattern sets for a short to ground in the sensor supply voltage circuit.

Diagnostic Indicators

Diagnostic Trouble Code (DTC) Clearing

The rear parking assist diagnostic sequences may be cleared in one of the following ways

Vehicle Moving

IMPORTANTThe sequences will not clear if the rear parking assist diagnostic connector is grounded.
  1. Drive the vehicle forward at least 24 km/h (15 mph).
  2. Stop the vehicle.
  3. Turn the ignition OFF.

Vehicle Stopped

IMPORTANTThe sequences will not clear if the rear parking assist diagnostic connector is grounded.
  1. Turn the ignition ON.
  2. Place foot on the brake.
  3. Shift the vehicle into REVERSE within five seconds.
  4. Turn the ignition OFF.

Symptoms - Object Detection

IMPORTANTReview the system operation in order to familiarize yourself with the system functions. Refer to Object Detection Description and Operation .

Visual/Physical Inspection

  1. Inspect for aftermarket devices which could affect the operation of the system. Refer to «Checking Aftermarket Accessories»(/buick/lacrosse/i-2004-2009/remont/body-electrical/#how-to-diagnosis-repair-the-wiring-systems-testing__checking-aftermarket-accessories) .
  2. Inspect the easily accessible or visible system components for obvious damage or conditions which could cause the symptom.
  3. Make sure the rear parking assist sensors located on the vehicle rear bumper are clear. Remove any snow, mud or ice that is blocking the sensors.

Intermittent

Faulty electrical connections or wiring may be the cause of intermittent conditions. Refer to Testing for Intermittent Conditions and Poor Connections .

Symptom List

Refer to an appropriate symptom diagnostic procedure from the following list in order to diagnose the symptom

  1. «Rear Parking Assist Malfunction»(/buick/lacrosse/i-2004-2009/remont/collisionavoidance/#object-detection-system)
  2. «Rear Parking Assist Inoperative - Red Indicator Flashes»(/buick/lacrosse/i-2004-2009/remont/collisionavoidance/#object-detection-system__rear-parking-assist-inoperative-red)

Diagnostic Aids

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

StepActionValue(s)YesNo
Schematic Reference: Object Detection Schematics Connector End View Reference: Object Detection Connector End Views or Computer/Integrating Systems Connector End Views
1Did you review the operation and perform the necessary inspections?Go to Step 2Go to Symptoms - Object Detection
2Turn ON the ignition. Place foot on the BRAKE. Shift vehicle into REVERSE. Do all 3 display indicators illuminate for 2 seconds and then turn OFF?Go to Testing for Intermittent Conditions and Poor ConnectionsGo to Step 3
3Does the red indicator flash?Go to Rear Parking Assist Inoperative - Red Indicator FlashesGo to Step 4
4Do all of the indicators but one indicator illuminate?Go to Step 6Go to Step 5
5Does any indicator remain ON?Go to Step 7Go to Step 10
6Connect 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 16Go to Step 8
7Turn the ignition OFF. Disconnect the rear parking assist display. Turn ON the ignition. 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 9Go to Step 15
8Test the control circuit of the inoperative indicator for the following conditions: An open A short to battery voltage A high resistance Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 19Go to Step 15
9Test 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 19Go to Step 16
10Test 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 19Go to Step 11
11Test 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 19Go to Step 12
12Test 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 19Go to Step 13
13Turn the ignition OFF. Disconnect the rear parking assist display. Turn the ignition ON. 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 15Go to Step 14
14Test 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 19Go to Step 16
15Inspect 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 19Go to Step 17
16Inspect 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 19Go to Step 18
17Replace the rear parking assist display. Refer to Information Center Telltale Assembly Replacement . Did you complete the replacement?Go to Step 19
18Replace 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
19Operate the system in order to verify the repair. Did you correct the condition?System OKGo to Step 2

Rear Parking Assist Malfunction

Rear Parking Assist Inoperative - Red Indicator Flashes

StepActionValue(s)YesNo
Schematic Reference: Object Detection Schematics Connector End View Reference: Object Detection Connector End Views or Computer/Integrating Systems Connector End Views IMPORTANT: Before performing this procedure, ensure that the vehicle park brake is SET.
1Did you review the operation and perform the necessary inspections?Go to Step 2Go to Symptoms - Object Detection
2Turn ON the ignition. Place your foot on the BRAKE. Shift the vehicle into REVERSE. Does the red indicator continue to flash after the bulb check?Go to Step 3Go to Testing for Intermittent Conditions and Poor Connections
3Turn OFF the ignition. Remove all objects at least 2 meters from the rear bumper. Enter the diagnostic mode. Refer to Diagnostic Trouble Code (DTC) Displaying for more information. Does diagnostic indicator pattern #1, Diagnostic Trouble Code (DTC) Displaying , appear as shown in the diagnostic indicator table when you enter diagnostics?Go to Step 4Go to Step 14
4Does diagnostic indicator pattern #2, 3, 4 or 5, Diagnostic Trouble Code (DTC) Displaying , appear as shown in the diagnostic indicator table?Go to Step 9Go to Step 5
5Does diagnostic indicator pattern #6, Diagnostic Trouble Code (DTC) Displaying , appear as shown in the diagnostic indicator table?Go to Step 10Go to Step 6
6Does diagnostic indicator pattern #7, Diagnostic Trouble Code (DTC) Displaying , appear as shown in the diagnostic indicator table?Go to Diagnostic Trouble Code (DTC) Displaying and Diagnostic Trouble Code (DTC) ClearingGo to Step 7
7Does diagnostic indicator pattern #8, Diagnostic Trouble Code (DTC) Displaying , appear as shown in the diagnostic indicator table?Go to Step 8Go to Step 17
8Turn OFF the ignition. Disconnect only ONE rear object sensor. Perform the following actions after a rear object sensor is disconnected: Enter the diagnostic mode to determine if the diagnostic indicator pattern #8 will still be displayed. When the sensor causing the short to ground is disconnected, the diagnostic indicator pattern #8 will not be displayed. The diagnostic indicator pattern displayed will be any one of the diagnostic indicator patterns #2, #3, #4 and #5. Refer to Diagnostic Trouble Code (DTC) Displaying for more information on how to enter the diagnostic mode. Reconnect the rear object sensor when it is determined the sensor is not source of the short to ground. Clear the DTC. Refer to Diagnostic Trouble Code (DTC) Clearing . Repeat the above process for all rear object sensors to determine if the sensors are the source of the short to ground. Does diagnostic indicator pattern #8, Diagnostic Trouble Code (DTC) Displaying , still appear as shown in the diagnostic indicator table?Go to Step 15Go to Step 16
9Turn OFF the ignition. Connect the DMM between the signal circuit of the inoperative rear object sensor and the low reference circuit of the rear object sensor at the rear object sensor control module with the harness connected to the module. Turn ON the ignition. Place foot on BRAKE. Shift the vehicle into REVERSE. Measure the voltage between the signal circuit of the inoperative rear object sensor and the low reference circuit of the rear object sensor. Does the voltage measure greater than the specified value?7 VGo to Step 17Go to Step 11
10Turn OFF the ignition. Disconnect the rear object sensor control module connector. Measure the voltage between the rear parking assist chime signal circuit and a good ground. Does the voltage measure greater than the specified value?9.5 VGo to Step 17Go to Step 13
11Test the signal circuit of the inoperative rear object sensor for an open, for a short to ground and for a short to B+. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 22Go to Step 12
12Test the supply voltage circuit and the low reference circuit of the inoperative rear object sensor for an open between S408 or S407 and the rear object sensor. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 22Go to Step 16
13Test the rear parking assist chime signal 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 22Go to Step 18
14Test the rear parking assist diagnostic circuit for an open and for a high resistance. Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 22Go to Step 17
15Test the supply voltage circuit and the low reference circuit of the rear object sensors for the following conditions: An open A short to ground A high resistance Refer to Circuit Testing and Wiring Repairs . Did you find and correct the condition?Go to Step 22Go to Step 17
16Inspect for poor connections at the harness connector of the rear object sensor. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 22Go to Step 19
17Inspect 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 22Go to Step 20
18Inspect for poor connections at the harness connector of the rear integration module (RIM). Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs . Did you find and correct the condition?Go to Step 22Go to Step 21
19Replace the inoperative rear object sensor. Refer to Rear Object Sensor Replacement . Did you find and correct the condition?Go to Step 22
20Replace the rear object sensor control module. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement?Go to Step 22
21Replace the RIM. Refer to Control Module References for replacement, setup and programming. Did you complete the replacement?Go to Step 22
22Clear all codes. Refer to Diagnostic Trouble Code (DTC) Clearing . Operate the system in order to verify the repair. Did you correct the condition?System OKGo to Step 2
IMPORTANT
Before performing this procedure, ensure that the vehicle park brake is SET.

Rear Parking Assist Inoperative - Red Indicator Flashes

Removal Procedure

  1. Position your fingers between the headliner and the information center telltale assembly bezel and gently pull down to release the display bezel retainers.
  2. Use a small flat-bladed tool to release the locking tab at the rear of the telltale assembly.
  3. Tilt the information center telltale assembly down and pull down to remove.
  4. Disconnect the electrical connector from the information center telltale assembly.

Installation Procedure

  1. Connect the electrical connector to the information center telltale assembly.
  2. Position the information center telltale assembly into the headliner until locking tab locks into position. It may be necessary to rock the display into position.
  3. Install bezel by pressing into place until the locking tabs are fully seated.

Scheme 6

Scheme 6: Rear Object Sensor Replacement
CalloutComponent Name
Fastener Tightening Specifications: Refer to Fastener Tightening Specifications . Preliminary Procedures: Remove rear fascia. Refer to Fascia, Bracket, Bar, Absorber Replacement - Rear Bumper . IMPORTANT: Do not refinish previously painted sensors.
1Sensor, Rear Object Tip: Press tab to release sensor from retainer. Disconnect electrical connector. Paint the new rear object sensor. Refer to Basecoat/Clearcoat Paint Systems . Check the paint thickness to ensure it does not exceed 6 mils using a paint thickness gage suitable for non-ferrous metals. Refer to Paint Gages .
2Retainer, Rear Object
3Retainer, Rear Object
IMPORTANT
Do not refinish previously painted sensors.

Rear Object Sensor Replacement

  1. Remove the rear window shelf trim panel. Refer to «Trim Panel Replacement - Rear Window Shelf»(/buick/lacrosse/i-2004-2009/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.
  2. Disconnect the Rear Parking Assist (RPA) receiver electrical connector (2).
  3. Remove the fasteners from the RPA receiver.
  4. Remove the receiver from the rear shelf.
  1. Install the RPA receiver to the rear window shelf.
  2. Install the RPA receiver fastener.
  3. Connect the electrical connector (2) to the RPA receiver.
  4. Install the rear window shelf trim panel. Refer to «Trim Panel Replacement - Rear Window Shelf»(/buick/lacrosse/i-2004-2009/remont/exteriorinterior-trim/#interior-trim) in Interior Trim.

Object Detection Description and Operation

The ultrasonic rear parking assist (URPA) can help a driver determine how close an object is to the rear bumper within a defined rearward field of view.

The rear parking assist display is located inside the vehicle by the rear window. Refer to Object Detection Component Views for the location of the display. The display has 3 indicators that can be seen through the rearview mirror or by turning around when seated in the driver seat.

When the ignition is ON and the vehicle is placed into reverse, the URPA performs a bulb check. During the bulb check, the 3 indicators on the display illuminate for approximately 2 seconds to indicate that the system is working. The URPA performs a bulb check and operates when the following conditions are present

  1. The ignition is ON.
  2. The vehicle is placed in REVERSE (R).
  3. The vehicle speed is less than 5 km/h (3 mph). At speeds greater than 5 km/h (3 mph), the URPA is disable. The red indicator flashes to warn the driver that the URPA is disabled.

The URPA senses how close the vehicle is to an object. The distance is determined by the 4 ultrasonic sensors located on the rear bumper. When the system detects an object, one of the following will occur

  1. If the object is less than 0.3 m (11 in) away from the rear of the vehicle, the amber outside, amber middle and the red outside indicators flash and the chime sounds continuously.
  2. If the object is less than 0.3-0.5 m (11-20 in) away from the rear of the vehicle, the amber outside, amber middle and the red outside indicators are on and the chime sounds continuously.
  3. If the object is 0.5-1.0 m (20-40 in) away from the rear of the vehicle, the amber outside and the amber middle indicators are on.
  4. If the object is 1.0-1.5 m (40-60 in) away from the rear of the vehicle, the amber outside indicator is on and the chime sounds one time on the first detection of an object.

The URPA can detect objects 7.6 cm (3 in) wide and at least 25.4 cm (10 in) tall. It cannot detect objects above the level of the roof.

If the red indicator flashes continuously, the on-board diagnostic needs to be entered to determine if a malfunction is present. Refer to Diagnostic Trouble Code (DTC) Displaying .