Diagnostic Routine A

Diagnostic Routine A

Diagnostic Overview

All-Wheel Drive (AWD) System Functional Test

Refer to Wiring Diagram Set 34 for schematic and connector information Electrical Diagrams.

Normal Operation and Fault Conditions

The AWD (All-Wheel Drive) system is intended to optimally distribute torque between the rear and front wheels through the use of an electromagnetic clutch located in the rear differential.

Visual Inspection and Diagnostic Pre-checks

- Matching wheel/tire size, brand and tread wear

- Tire pressure

Pinpoint Test

1. CHECK FOR ATC (Active Torque Coupling) SOLENOID LOCK

1. Drive the vehicle on a dry, hard surface in turns while applying the accelerator pedal.

Is driveline wind-up/binding present in turns?






2. CHECK THE ACCELERATOR PEDAL POSITION (APP) PID (Parameter Identification)

1. Ignition ON.

2. Using a scan tool, view PCM (Powertrain Control Module) PID (Parameter Identification).

3. While monitoring the PCM (Powertrain Control Module) PID (Parameter Identification) APP, press the accelerator pedal.

Does APP PID (Parameter Identification) percent value match the approximate accelerator pedal position?






3. CHECK ABS (Anti-Lock Brake System) MODULE WHEEL SPEED SENSOR PIDs (Parameter Identifications)

1. Using a scan tool, view ABS (Anti-Lock Brake System) PIDs (Parameter Identifications).

2. While driving the vehicle at 48 km/h (30 mph), monitor the ABS (Anti-Lock Brake System) module wheel speed sensor PIDs (Parameter Identifications):

- 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?






4. CHECK VEHICLE ACCELERATION IN A STRAIGHT LINE

1. Carry out 3 accelerations from 0-48 km/h (0-30 mph) in a straight line (1 each with low, medium and full accelerator pedal application).

Does the vehicle pulsate or shudder while accelerating?






5. CHECK VEHICLE TURNING ABILITY

1. 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?






6. CHECK FOR TORQUE AT REAR WHEELS USING AWD (All-Wheel Drive) CLUTCH CONTROL COMMANDED (AWD_CLTCH_CMD) PID (Parameter Identification)

1. Ignition ON.

2. Using a scan tool, view PCM (Powertrain Control Module) PID (Parameter Identification).

3. Using the scan tool, command AWD_CLTCH_CMD to energize the ATC (Active Torque Coupling) solenoid to a constant 95% applied.

4. 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?