Lane Departure Warning System Malfunction
Lane Departure Warning 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 lane departure warning system is enabled and disabled through the lane departure switch. When enabled, the lane departure warning indicator will illuminate.
For vehicles without UGN, the switch and indicator are connected to the Frontview Camera Module. The Frontview Camera module supplies a reference voltage to the lane departure switch. When the switch is pressed, the signal circuit is grounded. When enabled, the Frontview Camera Module will illuminate the indicator located in the switch when lane departure warning system is enabled.
With UGN, the indicator and switch are connected to the Active Safety Control Module. The Active Safety Control Module receives input from several modules including the Parking Assist Control Module to provide additional features. Refer to 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) for additional information on UGN. The lane departure warning alerts and DTCs are from the Frontview Camera Module with the exception of the indicator DTCs which are sent by the Active Safety Control Module. There are no switch DTCs for vehicles with the Active Safety Control Module.
When the system is operating and can detect the lane markings, the Frontview Camera Module will request via serial data communications that the instrument cluster illuminate the green lane departure warning symbol. If the Frontview Camera Module detects that the vehicle unintentionally crosses a lane marking without the turn signal being used, the module will request the instrument cluster to flash the amber lane departure warning indicator. An audible warning will also sound three times when the amber lane departure warning indicator in the instrument cluster is flashing.
Diagnostic Aids
Certain factors will affect the operation of the lane departure warning system. When the system is operating properly, the indicator will illuminate on the instrument cluster. This indicates that all of the required operating conditions to permit lane departure warning have been met. The indicator will not appear when the system is having difficulty seeing the lines on the road or if the view of the frontview camera is blocked with mud, dirt, snow, ice, or 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, lane departure warnings may occasionally occur in a properly operating vehicle due to tar marks, shadows, cracks in the road, or other road imperfections. This is normal system operation and the vehicle does not require service. The driver information center may also display Lane Departure System Unavailable due to the temporary conditions listed above.
Additionally, the Frontview Camera Disable History can give useful hints about what affected the operation of the lane departure warning system. For the Frontview 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
1. Ignition ON.
2. Verify that DTC B356A is not set.
• If the DTC is set
Refer to DTC B356A B356A.
• If the DTC is not set
3. Verify that DTC B0987 is not set.
• If the DTC is set
Refer to DTC B0987 B0987.
• If the DTC is not set
4. Verify the scan tool Frontview Camera System Status parameter is Normal.
• If the parameter is Undefined or Malfunction
Refer to Diagnostic Aids.
• If the parameter is Normal
5. Verify the scan tool Lane Departure Warning Switch Status parameter changes between ON and OFF when pressing the lane departure warning switch.
• If the parameter does not change between On and Off
Refer to Circuit/System Testing - Lane Departure Warning Switch Malfunction.
• If the parameter changes between On and Off
6. Verify the scan tool Lane Departure Warning Indicator Status parameter changes change between On and Off when pressing the lane departure warning switch.
• If the parameter does not change between On and Off
Refer to Circuit/System Testing - Lane Departure Warning Switch Indicator Malfunction.
• If the parameter changes between On and Off
7. All OK.
Circuit/System Testing
Lane Departure Warning Switch Circuit Malfunction (without UGN)
1. Ignition OFF, disconnect the harness connector at the S48C Multifunction Switch 1 - Instrument Panel. 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 5 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 ground 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 the scan tool Lane Departure Warning Switch parameter is Off.
• If not Off
1. Ignition OFF, disconnect the harness connector at the K109 Frontview Camera Module.
2. Test for infinite resistance between the S48C Multifunction Switch 1 - Instrument Panel signal circuit terminal 6 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 Off
5. Install a 3 A fused jumper wire between the signal circuit terminal 6 and ground.
6. Verify the scan tool Lane Departure Warning Switch parameter is On.
• If not On
1. Ignition OFF, disconnect the harness connector at the K109 Frontview Camera Module, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K109 Frontview Camera Module.
• If On
7. Test or replace the S48C Multifunction Switch 1 - Instrument Panel.
Lane Departure Warning Switch Indicator Circuit Malfunction (without UGN)
1. Ignition OFF, disconnect the harness connector at the S48C Multifunction Switch 1 - Instrument Panel, ignition ON.
Note: Verify interior lighting dimming is turned all the way up.
2. Test for 6.2-10.9 V between the dimming control circuit terminal 3 and ground terminal 5.
• If less than 6.2 V
1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground in the circuit.
• If infinite resistance
3. 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, refer to Interior Backlighting Malfunction Interior Backlighting Malfunction.
• If greater than 10.9 V
1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module, 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, refer to Interior Backlighting Malfunction Interior Backlighting Malfunction.
• If between 6.2-10.9 V
3. Connect a test lamp between the control circuit terminal 2 and B+.
4. Verify the test lamp turns ON and OFF when Commanding the Lane Departure Warning Indicator ON and OFF with a scan tool.
• If the test lamp is always OFF
1. Ignition OFF, disconnect the harness connector at the K109 Frontview Camera Module, 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 S48C Multifunction Switch 1 - Instrument Panel.
• If the test lamp is always ON
1. Ignition OFF, disconnect the harness connector at the K109 Frontview Camera Module.
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 K109 Frontview Camera Module.
• If the test lamp turns ON and OFF
5. Test or replace the S48C Multifunction Switch 1 - Instrument Panel.
Lane Departure Warning Switch Circuit Malfunction (with UGN)
1. Ignition OFF, disconnect the harness connector at the S48C Multifunction Switch 1 - Instrument Panel. 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 5 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 ground 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 the scan tool Lane Departure Warning Switch parameter is Off.
• If not Off
1. Ignition OFF, disconnect the harness connector at the K124 Active Safety Control Module.
2. Test for infinite resistance between the S48C Multifunction Switch 1 - Instrument Panel signal circuit terminal 6 and ground.
• If less than infinite resistance, repair the short to ground on the circuit.
• If infinite resistance, replace the K124 Active Safety Control Module.
• If Off
5. Install a 3 A fused jumper wire between the signal circuit terminal 6 and ground.
6. Verify the scan tool Lane Departure Warning Switch parameter is On.
• If not On
1. Ignition OFF, disconnect the harness connector at the K124 Active Safety Control Module, ignition ON.
2. Test for less than 1 V between the signal circuit and ground.
• If 1 V or greater, repair the short to voltage on the circuit.
• If less than 1 V
3. Test for less than 2 ohms in the signal circuit end to end.
• If 2 ohms or greater, repair the open/high resistance in the circuit.
• If less than 2 ohms, replace the K124 Active Safety Control Module.
• If On
7. Test or replace the S48C Multifunction Switch 1 - Instrument Panel.
Lane Departure Warning Switch Indicator Circuit Malfunction (with UGN)
1. Ignition OFF, disconnect the harness connector at the S48C Multifunction Switch 1 - Instrument Panel.
Note: Verify interior lighting dimming is turned all the way up.
2. Ignition ON, test for 6.2-10.9 V between the dimming control circuit terminal 3 and ground terminal 5.
• If less than 6.2 V
1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module.
2. Test for infinite resistance between the control circuit and ground.
• If less than infinite resistance, repair the short to ground in the circuit.
• If infinite resistance
3. 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, refer to Interior Backlighting Malfunction Interior Backlighting Malfunction.
• If greater than 10.9 V
1. Ignition OFF, disconnect the harness connector at the K9 Body Control Module, 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, refer to Interior Backlighting Malfunction Interior Backlighting Malfunction.
• If between 6.2-10.9 V
3. Connect a test lamp between the control circuit terminal 2 and B+.
4. Verify the test lamp turns ON and OFF when Commanding the Lane Departure Warning Indicator ON and OFF with a scan tool.
• If the test lamp is always OFF
1. Ignition OFF, disconnect the harness connector at the K124 Active Safety Control Module, 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 S48C Multifunction Switch 1 - Instrument Panel.
• If the test lamp is always ON
1. Ignition OFF, disconnect the harness connector at the K124 Active Safety Control Module.
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 K124 Active Safety Control Module.
• If the test lamp turns ON and OFF
5. Test or replace the S48C Multifunction Switch 1 - Instrument Panel.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the repair.
* Hazard Warning Switch Replacement Service and Repair - S48C Multifunction Switch 1 - Instrument Panel replacement.
* Control Module References Control Module References for Active Safety Control Module and Frontview Camera Module replacement, programming and setup