Circuit Description

EBCM and PCM simultaneously control traction control. EBCM sends a requested torque message via a Pulse Width Modulated (PWM) signal to PCM. Duty cycle of signal is used to determine how much engine torque EBCM is requesting PCM to deliver. Normal values are 10-90 percent duty cycle. Signal should be at 90 percent when traction control is not active and at lower values during traction control activations. PCM supplies pull up voltage that EBCM switches to ground to create signal.

If a defective requested torque signal is detected by PCM, a message is broadcasted back to EBCM via class 2 data line. DTC sets anytime ignition voltage is present and PCM detects requested torque PWM signal is less than 5 percent duty cycle or greater than 95 percent duty cycle or requested torque PWM signal is not present for 10 seconds.