Test I: The Traction Control System Is Inoperative
Pinpoint Test I: The Traction Control System is InoperativeRefer to Vehicle/Diagrams, Vehicle Dynamic Systems for schematic and connector information.
Normal Operation
If the rear wheels begin to loose traction during acceleration, the ABS module will use the hydraulic control unit (HCU) to modulate brake fluid pressure to the rear brake calipers. At the same time, the ABS module sends a message to the PCM over the high-speed controller area network (HS-CAN) bus to modulate engine torque. Engine torque modulation is achieved by regulating fuel and spark to the cylinders. Once the rear wheels return to the desired speed, the ABS module stops modulating the brake fluid pressure and stops sending the message to the PCM.
This pinpoint test is intended to diagnose the following:
^ Wiring, terminals or connectors
^ Instrument cluster
^ ABS module
