Forward Collision Alert System Malfunction
Forward Collision Alert System Malfunction
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
Diagnostic Fault Information
Circuit/System Description
The forward collision alert system is controlled by the frontview camera module mounted on the windshield. The system is designed to detect vehicles directly ahead, within a distance of approximately 60 meters (197 ft). The forward collision alert system operates at speeds above 40 km/h (25 mph). When the system detects a vehicle in the path ahead, the green vehicle ahead alert indicator in the driver information center is illuminated. When approaching another vehicle too rapidly, the collision alert symbol will flash and the radio will beep or the haptic seat will pulse, depending on user configuration. The red collision alert display will stay continuously illuminated if the vehicle ahead remains much too close. These actions are requested by the frontview camera module via serial data. The forward collision alert switch is part of the left steering wheel controls and is used to adjust the timing sensitivity of the front collision alert system.
Diagnostic Aids
Certain factors will affect the operation of the forward collision alert system. Forward collision alert is intended to detect vehicles. It is not intended to warn the driver of any objects that are not detected as a vehicle such as pedestrians, animals, signs, guard rails, bridges, construction barrels or other stationary or slow moving objects. In few cases the camera may inadvertently detect a vehicle that is not in the path ahead, or the system may occasionally provide unrealistic alerts. This could occur with a turning vehicle ahead, guard rails, traffic signs, or other stationary objects. This is normal operation, the vehicle does not need service. When the system is operating properly, the green vehicle ahead alert indicator will illuminate on the vehicle direction display when the system detects a vehicle in the path ahead. This indicates that all of the required operating conditions are met. The green vehicle ahead alert indicator will not appear when the system is having difficulty seeing other vehicles on the road. This can occur if the front view camera is blocked with mud, dirt, snow, ice, slush, if the windshield is damaged, or when weather limits visibility, such as while driving in fog, rain, or snow conditions. This is normal operation, the vehicle does not need service.
Additionally, the Front View Camera Disable History can give useful hints about what affected the operation of the forward collision alert system. For the Front View Camera Disable History, refer to DTC B1011 B1011.
Reference Information
Schematic Reference
Object Detection Schematics [1][2]Collision Avoidance and Parking Assist Systems
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
Object Detection Description and Operation (with Active Safety System - UGN) Object Detection Description and Operation (with Active Safety System - UGN)Object Detection Description and Operation (with rear vision camera - UVC) Object Detection Description and Operation (with rear vision camera - UVC)Object Detection Description and Operation (with front and rear park assist - UD5) Object Detection Description and Operation (With Front and Rear Park Assist - UD5)Object Detection Description and Operation (with rear park assist - UD7) Object Detection Description and Operation (With Rear Park Assist - UD7)Object Detection Description and Operation (with side blind zone alert - UFT) Object Detection Description and Operation (with side blind zone alert - UFT)Object Detection Description and Operation (with rear cross traffic alert - UFG) Object Detection Description and Operation (With Rear Cross Traffic Alert - UFG)Object Detection Description and Operation (with lane departure warning - UFL) Object Detection Description and Operation (With Lane Departure Warning - UFL)Object Detection Description and Operation (with forward collision alert - UEU) Object Detection Description and Operation (With Forward Collision Alert - UEU)Object Detection Description and Operation (with Haptic Signal Motor Seat) Object Detection Description and Operation (with Haptic Signal Motor Seat)
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
Note: Refer to Diagnostic Aids before performing Circuit/System Verification.
1. Ignition ON.
2. Verify the scan tool Forward Collision Alert Function Status parameter is not Malfunction.
• If the parameter is Malfunction
Refer to Circuit/System Testing - Frontview Camera Module Malfunction
• If parameter is not Malfunction
3. Verify the forward collision alert indicators illuminate momentarily when turning ignition OFF and then ON.
• If the indicators do not illuminate
Refer to Circuit/System Testing - Forward Collision Alert Indicator Malfunction
• If the indicators illuminate
4. Verify the driver information center forward collision alert distance indicator toggles between far, medium, near and off.
• If the setting does not change
Refer to Circuit/System Testing - Forward Collision Alert Switch Malfunction.
• If the setting changes
5. Verify the area of the K109 Frontview Camera Module is not contaminated.
• If contaminated
Clean the windshield
• If not contaminated
6. All OK.
Circuit/System Testing
Note: Perform the Circuit/System Verification before proceeding with Circuit/System Testing.
Frontview Camera Module Malfunction
1. Ignition OFF and all vehicle systems OFF, disconnect the harness connector at the K109 Frontview Camera Module. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal 1 and ground.
• If 10 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Verify a test lamp illuminates between the B+ circuit terminal 3 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF.
2. Test for less than 2 ohms in the B+ circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF.
2. Test for infinite resistance between the B+ circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K109 Frontview Camera Module.
• If the test lamp illuminates
4. Replace the K109 Frontview Camera Module.
Forward Collision Alert Indicator Malfunction
1. Ignition OFF, and all vehicle systems OFF, disconnect the harness connector at the P43 Collision Alert Indicators. It may take up to 2 minutes for all vehicle systems to power down.
2. Test for less than 10 ohms between the ground circuit terminal 4 and ground.
• If 10 ohms or greater
1. Ignition OFF.
2. Test for less than 2 ohms in the ground circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, repair the open/high resistance in the ground connection.
• If less than 10 ohms
3. Ignition ON.
4. Verify a test lamp illuminates between the ignition circuit terminal 1 and ground.
• If the test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF.
2. Test for less than 2 ohms in the ignition circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF.
2. Test for infinite resistance between the ignition circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the P43 Collision Alert Indicators.
• If the test lamp illuminates
5. Connect a test lamp between the control circuit terminal 2 and the ignition circuit terminal 1.
6. Verify the test lamp turns ON and OFF when commanding the Instrument Cluster All Indicators ON and OFF with a scan tool.
• If the test lamp is always OFF
1. Ignition OFF, disconnect the harness connector at the P16 Instrument Cluster, ignition ON.
2. Test for less than 1 V between the control circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Ignition OFF.
4. Test for less than 2 ohms in the control circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the P16 Instrument Cluster.
• If the test lamp is always ON
1. Ignition OFF, disconnect the harness connector at the P16 Instrument Cluster.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the P16 Instrument Cluster.
• If the test lamp turns ON and OFF
7. Test or replace the P43 Collision Alert Indicators.
Forward Collision Alert Switch Malfunction
1. Ignition OFF, disconnect the harness connector at the S70L Steering Wheel Controls Switch - Left, ignition ON.
2. Verify a test lamp illuminates between the ignition circuit terminal 8 and ground.
• If test lamp does not illuminate and the circuit fuse is good
1. Ignition OFF.
2. Test for less than 2 ohms in the Ignition circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, verify the fuse is not open and there is voltage at the fuse.
• If the test lamp does not illuminate and the circuit fuse is open
1. Ignition OFF.
2. Test for infinite resistance between the Ignition circuit and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the S70L Steering Wheel Controls Switch - Left.
• If the test lamp illuminates
3. Ignition OFF, connect the harness connector at the S70L Steering Wheel Controls Switch - Left, disconnect the X3 harness connector at the K9 Body Control Module, ignition ON.
4. Test for less than 1 V between the signal circuit terminals listed below and ground:
* Terminal 4
* Terminal 16
• If 1 V or greater
Repair the short to voltage on the signal circuit.
• If less than 1 V
5. Ignition OFF.
6. Test for infinite resistance between the signal circuit terminals listed below and ground:
* Terminal 4
* Terminal 16
• If less than infinite resistance
Repair the short to ground on the signal circuit.
• If infinite resistance
7. Disconnect the harness connector at the S70L Steering Wheel Controls Switch - Left.
8. Test for less than 5 ohms between the circuit terminals listed below:
* S70L Steering Wheel Controls Switch - Left terminal 8 and K9 Body Control Module terminal 4.
* S70L Steering Wheel Controls Switch - Left terminal 9 and K9 Body Control Module terminal 16.
• If greater than 5 ohms
Repair the open/high resistance in the circuit.
• If less than 5 ohms
9. Test or replace the S70L Steering Wheel Controls Switch - Left.
Component Testing
Forward Collision Alert Switch
Static Test
1. Ignition OFF, disconnect the harness connector at the S70L Steering Wheel Controls Switch - Left.
2. Test for 7.0k-10.5k ohms between the control terminal 8 and the signal circuit terminal 9.
• If not between 7.0k-10.5k ohms
Replace the S70L Steering Wheel Controls Switch - Left.
• If between 7.0k-10.5k ohms
3. Test for 2.1k-3.1k ohms between the control terminal 8 and the signal circuit terminal 9 while pressing the switch.
• If not between 2.1k-3.1k ohms
Replace the S70L Steering Wheel Controls Switch - Left.
• If between 2.1k-3.1k ohms
4. All OK.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Cruise Control Switch Replacement Service and Repair - Steering Wheel Controls Switch - Left replacement.
* Forward Collision Alert Display Replacement Service and Repair
* Control Module References Control Module References for Frontview Camera Module replacement, programming and setup