Pinpoint Test A: All Wheel Drive (AWD) System Functional Test

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 delivered to the front wheels. If wheel slip between the front and rear wheels is detected, or if the vehicle is under heavy acceleration, the AWD system increases torque to the rear wheels to prevent or control wheel slip.

This pinpoint test is intended to diagnose the following:

• An AWD system concern without on-demand or continuous DTCs present.

PINPOINT TEST A: AWD SYSTEM FUNCTIONAL TEST 

1. A1 CHECK FOR WRENCH LIGHT PROVE-OUT 
   • Turn the ignition to the ON position and observe the wrench light.
   • Does the wrench light illuminate for 3 seconds and then turn OFF? 
   1. YES  : Go to  A2.
   2. NO  : REFER to INSTRUMENT CLUSTER (IC), MESSAGE CENTER, AND WARNING CHIMES article for further diagnosis of the instrument cluster (IC).
2. A2 CHECK FOR ACTIVE TORQUE CONTROL COUPLING (ATCC) SOLENOID (PART OF REAR AXLE) LOCK 
   • Drive the vehicle on a dry, hard surface in turns while applying the accelerator pedal.
   • Is driveline wind-up present in turns? 
   1. YES  : With the ignition switch in ON position, allow the ATCC solenoid to cool down for at least 10 minutes and repeat the test. CHECK for wind-up again. If no wind-up is found, go to  A3; if still present, go to Pinpoint Test F .
   2. NO  : Go to  A3.
3. A3 CHECK FOR VALID ACCELERATOR PEDAL POSITION MONITORING THE ACCELERATOR PEDAL POSITION (AP) PID 
   • Enter the following diagnostic mode on the diagnostic tool: DataLogger - 4X4 Control Module
   • Monitor the AP PID while pressing the accelerator pedal.
   • Does the accelerator pedal position match the AP PID percent value? 
   1. YES  : Go to  A4.
   2. NO  : REFER to the Introduction - Gasoline Engines article to diagnose the accelerator pedal position sensor concern.
4. A4 CHECK 4X4 CONTROL MODULE WHEEL SPEED SENSOR 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  A5.
   2. NO  : Go to Pinpoint Test G .
5. A5 CHECK VEHICLE ACCELERATION IN A STRAIGHT LINE 
   • Carry out 3 accelerations from 0-48 km/h (0-30 mph) in a straight line (one each with low, medium and full accelerator pedal application).
   • Does the vehicle pulsate or shudder while accelerating? 
   1. YES  : Go to Pinpoint Test F .
   2. NO  : Go to  A6.
6. A6 CHECK VEHICLE TURNING ABILITY 
   • Drive the vehicle in a fully locked turn, on dry pavement, at 8 km/h (5 mph).
   • Does the vehicle bind in the turn or resist turning? 
   1. YES  : Go to Pinpoint Test F .
   2. NO  : Go to  A7.
7. A7 CHECK FOR TORQUE AT REAR WHEELS USING PWM OUTPUT CONTROL COMMAND #1 (CLCH_SOL) ACTIVE COMMAND 
   • Enter the following diagnostic mode on the diagnostic tool: DataLogger - 4X4 Control Module
   • Using the scan tool, command CLCH_SOL to energize the ATCC solenoid to a constant 100% applied.
   • Drive the vehicle in a fully locked turn, on dry pavement, at 8 km/h (5 mph).
   • Does the vehicle bind in the turn or resist turning? 
   1. YES  : End the active command. The concern cannot be duplicated at this time. RETURN the vehicle to the customer.
   2. NO  : End the active command. CHECK that the driveshaft rotates when the transaxle is in gear. If yes, go to Pinpoint Test E . If no, CHECK the PTU. REFER to TRANSFER CASE - POWER TRANSFER UNIT (PTU) article.