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Tahoe / Yukon Service Manual

Service Drivers Assist Malfunction

Diagnostic Instructions Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. Review Strategy Based Diagnosis for an overview of the diagnostic approach. Diagnostic Procedure Instructions provides an overview of each diagnostic category. Circuit/System Description For an overview of the Driver’s Assistance system, refer to: Active Safety System Description and Operation Forward Collision Alert Description and Operation Lane Keep Assist Description and Operation Parking Assist Description and Operation Diagnostic Aids The Service Driver’s Assist Message is displayed because of a fault in the Driver’s Assistance System. When attempting to diagnose the system, it is important to discuss with the customer the conditions under which the apparent malfunction occurred. It is also critical to identify when the apparent malfunction occurred when attempting to replicate the condition. The K124 Image Processing Module has several available scan tool data lists that can help identify what may have caused a Service Driver’s Assist Message. The scan tool Disable History Data list identifies conditions that will cause a Driver’s Assistance System inhibit, which would prevent features from engaging when requested by the driver, or that will cause a feature disengagement, which would immediately disengage the feature if the driver was actively utilizing the system. The scan tool Disable History Data list has parameters that identify the last eight causes of an inhibit and the last eight causes of a disengage. For each Inhibit History and Disengage History parameter, extra information is included in additional parameters: Odometer at First Malfunction, Odometer at Last Malfunction, Diagnostic Status, Malfunction Counter, and Ignition Cycles Since Last Diagnostic Event. The scan tool parameters are a rolling snapshot of the last eight inhibit and disengage reasons, however, if the same condition causes an inhibit or disengage, the reason will not be logged in the next parameter. Instead, the Malfunction Counter parameter will increment, and the Odometer at Last Malfunction parameter will update with the most recent odometer value that the condition occurred. The B174W Front View Camera - Windshield may have trouble functioning under the following scenarios: Dirty windshield glass or obstruction on windshield. This may included dirt, snow, or ice, a tinted windshield, windshield tint strips, or vinyl strips or graphics on the windshield. Additionally, other obstructions such as brush guards or hood deflectors may obstruct view of the B174W  Camera – Windshield and hinder it’s ability to identify objects, vehicles, and lane markings. The B174W Frontview Camera – Windshield is not properly installed. Verify it is snapped into tabs and is secure. Ensure the bracket is in the correct location by comparing to a known good vehicle. This is especially important if the windshield was recently replaced. Some aftermarket windshield may have the B174W Frontview Camera – Windshield in the incorrect location. Improper installation of a replacement windshield may also prevent completion of the learn if the windshield was not centered and leveled in the vehicle’s windshield opening. Driving through snow or fog, or driving directly into the sun. Driving on windy or hilly roads. Inspect the B233B Radar Sensor Module – Long Range for proper mounting and alignment. In most cases, a mounting or alignment issue may be caused by a front end impact/collision that may or may not be obvious. Physically check the radar mounting bracket for damage and ensure it is in alignment. Place the vehicle on a level surface. Use an angle gauge or level to make sure the bracket is mounted 90 degrees (+/- 3 degrees). Visually inspect the vehicle for any aftermarket add on equipment like bug deflectors, windshield tint/banners, grille emblems, push bars, license plates, etc.  These items could block the radar / camera’s view.  Discuss with the customer to see if this concern started after the installation of the aftermarket equipment.  Remove any aftermarket items and retest system for proper operation. The safety alert seats use the P45LR Front Seat Lane Departure Warning Actuator - Left Rear and P45RR Front Seat Lane Departure Warning Actuator - Right Rear, located in the driver seat cushion, to provide haptic pulses. The safety alert seat pulses the left, right or both sides of the seat to alert drivers to the direction of the possible danger when the park assist, lane keep assist, or forward collision alert system detects a possible collision. On vehicles with RPO A45, the K40D Driver Seat Adjuster Memory Module controls the warning actuators. On vehicles without RPO A45, the K9 Body Control Module controls the warning actuators. Excessive actuator use, actuators on continually on for 60 seconds or greater, will illuminate the Service Drivers Assist message and may indicate a repair action is not required. Reference Information Schematic Reference Driver Assistance Systems Schematics Connector End View Reference Master Electrical Component List Electrical Information Reference Circuit Testing Connector Repairs Testing for Intermittent Conditions and Poor Connections Wiring Repairs Scan Tool Reference Control Module References Circuit/System Verification

  1. Ignition ON.
  2. Verify there are no DTCs set. ⇒ If any DTCs are set Refer to Diagnostic Trouble Code (DTC) List - Vehicle ⇓ If no DTCs are set
  3. Use the following K124 Image Processing Module scan tool Disable History Data parameters as described in Diagnostic Aids to identify the potential cause of the Service Driver’s Assist message to diagnose and repair as necessary: Adaptive Cruise Control Disengage History Adaptive Cruise Control Inhibit History Lane Keep Assist Event History Front Impact Mitigation Event History
  4. Drive the vehicle.
  5. Verify the parking assist indicator turns on and off when pressing and releasing the parking assist switch function properly, and there are no service messages displayed related to the system. ⇒ If the parking assist system is not operating properly Diagnose any faults in the system. Refer to: Parking Assist System Malfunction ⇓ If the parking assist system is operating properly
  6. Verify the lane keep assist and forward collision alert systems are able to be turned on and off using their respective control switches, function properly, and there are no service messages displayed related to either system. ⇒ If the lane keep assist and forward collision alert system is not operating properly Diagnose any faults in the system. Refer to: Symptoms - Driver Assistance Systems ⇓ If the lane keep assist and forward collision alert system are operating properly
  7. Press and release the Adaptive Cruise Control Gap Switch. Verify the adaptive cruise control gap setting on the P9 Driver Information Center Display changes between Far, Medium, and Near with each button press. ⇒ If the gap setting does not change Diagnose any faults in the system. Refer to: Adaptive Cruise Control Malfunction ⇓ If the gap setting changes
  8. Drive the vehicle.
  9. Verify the adaptive cruise control system is able to be engaged and disengaged normally and all systems functions are operating as designed. ⇒ If an adaptive cruise control system malfunction is identified Diagnose any faults in the system. Refer to: Adaptive Cruise Control Malfunction ⇓ If the adaptive cruise control system is operating as designed
  10. All OK. A fault is currently not present and may be an intermittent condition. Refer to Diagnostic Aids. Repair Instructions Perform the Diagnostic Repair Verification after completing the repair. Driver Assistance Systems Component Replacement Reference Control Module References for control module replacement, programming, and setup