Code P1571, Traction Control Desired Torque Out Of Range: Notes

WARNING: This page is about a different car, the 1994 Oldsmobile Ninety-Eight and 1994 Buick Park Avenue. However, it is still accessible from the selected car via links, so may be relevant.

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.

When Code P1571 is set, PCM will command EBTCM via serial data circuit to set ABS/TCS DTC 75, turn off traction control, and illuminate TRACTION OFF indicator. P1571 does not illuminate the Malfunction Indicator Light (MIL).

NOTE: Test numbers refer to numbers on diagnostic chart.

Checks circuit for an open or short to ground.
Ensures EBTCM is proving a proper PWM signal to PCM.