Pinpoint Test C: 4X4 Control Module Received No/Invalid Data From ABS Module

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 on-demand four wheel drive (4WD) system uses data from other systems as inputs to the 4X4 control module. The 4X4 control module uses the inputs to determine the appropriate duty cycle to send to the active torque control coupling (ATCC) (part of rear axle) solenoid that delivers the desired torque to the rear wheels. Specific inputs to the 4X4 control module are: accelerator pedal position output from the PCM, transmission range from the PCM, brake system status and all 4 wheel speeds from the ABS module. Communication between the 4X4 control module and other modules is obtained through the high-speed controller area network (HS-CAN). If the 4X4 control module loses communication with, or receives invalid data from any of the necessary modules, DTCs are set and the 4X4 control module may not allow 4WD operation.

DTC U0415 Invalid Data Received from Anti-lock Brake System (ABS) Control Module - When the 4X4 control module receives invalid HS-CAN bus data or invalid wheel speed(s) from the ABS module for more than 30 seconds, this DTC is set.

This pinpoint test is intended to diagnose the following:

ABS module

PINPOINT TEST C: 4X4 CONTROL MODULE RECEIVED NO/INVALID DATA FROM ABS MODULE

NOTE: This test must be carried out on a hard surface in an area without traffic.

NOTE: Carry out Inspection and Verification as outlined before carrying out this pinpoint test.

C1 CHECK FOR ABS MODULE DTCs
- Key in ON position.
- Carry out the ABS module self-test.
- Review the results of the ABS module self-test.
- Are any DTCs present?
1. YES : REFER to VEHICLE DYNAMIC SYSTEMS article for further diagnosis of the ABS.
2. NO : Go to C2.
C2 CHECK WHEEL SPEED SENSORS PIDs
- Enter the following diagnostic mode on the diagnostic tool: DataLogger - 4X4 Control Module
- While driving the vehicle at 32 km/h (20 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)
- Do the 4 wheel speed sensors match the speedometer and are they within 3 km/h (1.8 mph) of each other?
1. YES : The system is operating correctly at this time. CLEAR the DTCs. REPEAT the self-test.
2. NO : REFER to VEHICLE DYNAMIC SYSTEMS article for further diagnosis of the ABS.