Circuit Description

Traction control system uses anti-lock brake system in conjunction with PCM fuel and ignition controls to limit drive wheel slippage during acceleration. PCM controlled portion of traction control system reduces engine torque by any or all of following methods.

• Retarding spark advance.
• Altering air/fuel ratio.
• Altering boost duty cycle (VIN 1 only).
• Shutting off up to 3 injectors.

To determine amount of torque reduction required, PCM monitors desired torque PWM signal circuit from Electronic Brake and Traction Control Module (EBTCM). PCM also provides a delivered torque PWM signal, informing EBTCM how much torque is being produced by engine. Code P1571 will set when the following condition is present.

• If desired torque signal PWM duty cycle is less than 5 percent or greater than 95 percent. Code P1571 will set indicating a problem with desired torque input on circuit.