Pinpoint Test E: Vehicle Binds in a Turn Or Resists Turning/Pulsates Or Shudders in a Straight Line
Four Wheel Drive (4WD) Systems
Pinpoint Test E: Vehicle Binds in a Turn or Resists Turning/Pulsates or Shudders in a Straight Line
Refer to Wiring Diagram Set 34, All Wheel Drive (AWD) for schematic and connector information Electrical Diagrams.
Normal Operation
In order for the All-Wheel Drive (AWD) system to function correctly, tires and wheels must be the same size, be in good condition and the front and rear axle ratios must match. When the AWD (All-Wheel Drive) system is functioning properly, there should be no perceived speed difference between the front and rear axles when launching or driving the vehicle on any uniform surface. Traction should be similar to a part time Four-Wheel Drive (4WD) system in 4H (4X4 HIGH), but have no binding in turns.
This pinpoint test is intended to diagnose the following:
- Rear axle
- Wheels/tires
- All-Wheel Drive (AWD) relay module
PINPOINT TEST E : VEHICLE BINDS IN A TURN OR RESISTS TURNING/PULSATES OR SHUDDERS IN A STRAIGHT LINE
WARNING: When directed to drive the vehicle as part of this test, drive the vehicle on a hard surface in an area without traffic to prevent a crash. Failure to follow these instructions may result in personal injury.
NOTE: Carry out a thorough inspection and verification as outlined before carrying out this pinpoint test. Refer to Inspection and Verification Four Wheel Drive (4WD) Systems.
E1 CHECK FOR TORQUE AT THE REAR WHEELS
- Ignition OFF.
- Disconnect: Active Torque Coupling (ATC) Solenoid (part of rear axle) C4347.
- Drive the vehicle in a straight line on dry pavement.
Is a pulsation or shudder still present?
Yes
REFER to Differential Assembly &/or Axle Shaft Assembly &/or Drive/Propeller Shafts, Bearings and Joints for additional axle diagnosis.
No
GO to E2.
E2 MONITOR THE AWD (All-Wheel Drive) CLUTCH CONTROL COMMANDED (AWD_CLTCH_CMD) PID
- Ignition OFF.
- Connect: ATC (Active Torque Coupling) Solenoid C4347.
- Ignition ON.
- Enter the following diagnostic mode on the scan tool: DataLogger- PCM.
- Monitor the AWD_CLTCH_CMD PID.
- Drive the vehicle no faster than 8 km/h (5 mph) in tight turns on dry pavement while monitoring the ATC (Active Torque Coupling) solenoid duty cycle.
Is the duty cycle greater than 20%?
Yes
GO to E3.
No
GO to Pinpoint Test B Pinpoint Test B: DTC P187B.
E3 CHECK FOR THE CORRECT WHEEL SPEEDS USING THE WHEEL SPEED SENSORS PIDs
- Enter the following diagnostic mode on the scan tool: DataLogger- ABS 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 2 km/h (1.2 mph) of each other?
Yes
GO to E4.
No
GO to Pinpoint Test B Pinpoint Test B: DTC P187B.
E4 MONITOR THE ACCELERATOR PEDAL POSITION (APP) PID
- Enter the following diagnostic mode on the scan tool: DataLogger- PCM.
- Monitor APP PID while pressing/releasing the accelerator pedal.
Does the PID percent value match the approximate accelerator pedal position?
Yes
GO to E5.
No
REFER to Computers and Control Systems Information to diagnose the engine control system.
E5 CHECK FOR CORRECT AWD (All-Wheel Drive) RELAY MODULE OPERATION
- Disconnect: AWD (All-Wheel Drive) Relay Module C4379.
- Disconnect: ATC (Active Torque Coupling) Solenoid C4347.
- Check the AWD (All-Wheel Drive) Relay Module harness and component side connectors for:
- corrosion.
- pushed-out/bent pins.
- Check the harness between the AWD (All-Wheel Drive) relay module and the ATC (Active Torque Coupling) solenoid.
- Connect: AWD (All-Wheel Drive) relay module C4379.
- Connect: ATC (Active Torque Coupling) Solenoid C4347.
- Operate the system and determine if the concern is still present.
Is the concern still present?
Yes
INSTALL a new AWD (All-Wheel Drive) relay module. REFER to All Wheel Drive (AWD) Relay Module .
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector.