Pinpoint Test F: Vehicle Binds in a Turn or Resists Turning/Pulsates or Shudders in a Straight Line

Refer to appropriate SYSTEM WIRING DIAGRAMS - EDGE or SYSTEM WIRING DIAGRAMS - MKX article for All Wheel Drive (AWD) schematic and connector information.

Normal Operation 

The all wheel drive (AWD) system continuously monitors vehicle conditions and automatically adjusts the torque distribution between the front and rear wheels. During normal operation, most of the torque is sent to the front wheels. If wheel slip between the front and rear wheels is detected or the vehicle is under heavy acceleration, the AWD system increases torque to the rear wheels.

This pinpoint test is intended to diagnose the following:

• Rear axle
• Wheels/tires
• PCM
• ABS module
• 4X4 control module
• Circuitry

PINPOINT TEST F: VEHICLE BINDS IN A TURN OR RESISTS TURNING/PULSATES OR SHUDDERS IN A STRAIGHT LINE 

1. F1 CHECK FOR TORQUE AT THE REAR WHEELS 
   • Key in OFF position.
   • Disconnect: Active Torque Control Coupling (ATCC) Solenoid (Part of Rear Axle) C4347
   • Drive the vehicle in a straight line on dry pavement.
   • Is a pulsation or shudder still present? 
   1. YES  : REFER to DRIVELINE SYSTEM - GENERAL INFORMATION article for additional axle diagnosis.
   2. NO  : Go to  F2.
2. F2 CHECK TO SEE IF THE ATCC SOLENOID IS BEING COMMANDED ON MONITORING 4WD CLUTCH PWM STATUS (4WDCPWMST) PID 
   • Key in OFF position.
   • Connect: ATCC Solenoid C4347
   • Key in ON position.
   • Enter the following diagnostic mode on the diagnostic tool: DataLogger - 4X4 Control Module
   • Monitor the 4WDCPWMST PID.
   • Drive the vehicle no faster than 8 km/h (5 mph) in tight turns on dry pavement while monitoring the ATCC solenoid duty cycle.
   • Is the duty cycle greater than 20%? 
   1. YES  : Go to  F3.
   2. NO  : Go to Pinpoint Test G .
3. F3 CHECK FOR THE CORRECT WHEEL SPEEDS USING THE WHEEL SPEED SENSORS PIDs 
   • Enter the following diagnostic mode on the diagnostic tool: DataLogger - 4X4 Control Module
   • While driving the vehicle at 48 km/h (30 mph), monitor the following wheel speed sensor PIDs:
     • Left Front Wheel Speed Sensor (LF_WSPD)
     • Left Rear Wheel Speed Sensor (LR_WSPD)
     • Right Front Wheel Speed Sensor (RF_WSPD)
     • Right Rear Wheel Speed Sensor (RR_WSPD)
   • Are all 4 wheel speeds within 3 km/h (1.8 mph) of each other? 
   1. YES  : Go to  F4.
   2. NO  : Go to Pinpoint Test G .
4. F4 CHECK FOR VALID ACCELERATOR PEDAL POSITION MONITORING ACCELERATOR PEDAL POSITION (AP) PID 
   • Key ON, engine OFF (KOEO).
   • Enter the following diagnostic mode on the diagnostic tool: DataLogger - 4X4 Control Module
   • Monitor AP PID while pressing/releasing the accelerator pedal.
   • Does the accelerator position match the PID percent value? 
   1. YES  : Go to  F5.
   2. NO  : REFER to the Introduction - Gasoline Engines article to diagnose the engine control system.
5. F5 CHECK FOR CORRECT 4X4 CONTROL MODULE OPERATION 
   • Disconnect the 4X4 control module.
   • Check the harness and component side connectors for:
     • corrosion.
     • pushed-out/bent pins.
   • Check the ATCC solenoid jumper harness between the 4X4 control module and the ATCC solenoid, located on the rear subframe.
   • Connect the 4X4 control module and make sure it seats correctly.
   • Operate the system and determine if the concern is still present.
   • Is the concern still present? 
   1. YES  : INSTALL a new 4X4 control module. REFER to 4X4 CONTROL MODULE . CLEAR the DTCs. REPEAT the self-test.
   2. NO  : The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR the DTCs. REPEAT the self-test.