P1571

Diagnostic Chart:

Schematic:

CIRCUIT DESCRIPTION
The Traction Control System (TCS) uses the antilock brake system in conjunction with the Powertrain Control Module (PCM) fuel and ignition controls to limit drive wheel slippage during acceleration. The PCM controlled portion of the TCS reduces engine torque by any or all of the following methods:
- Retarding spark timing
- Altering air/fuel ratio
- Shutting off up to 3 injectors

To determine the amount of torque reduction required, the PCM monitors the TCS desired torque Pulse Width Modulated (PWM) signal from the Electronic Brake And Traction Control Module (EBTCM). The PCM also provides a TCS delivered torque PWM informing the EBTCM how much torque is being produced by the engine. The Desired Torque display on the scan tool indicates the amount of engine torque requested by the EBTCM. With the traction control inactive, the desired torque should vary between 99 and 100 percent. The Desired Torque display on the scan tool is not the PWM duty cycle.

CONDITIONS FOR SETTING THE DTC
- The desired torque signal PWM duty cycle is less than 10 percent or more than 95 percent.
- The above condition is present for at least 10 seconds.

ACTION TAKEN WHEN THE DTC SETS
- The PCM will not illuminate the Malfunction Indicator Lamp (MIL).
- The PCM will store conditions which were present when the DTC set as Failure Records data only. This information will not be stored as Freeze Frame data.

CONDITIONS FOR CLEARING THE MIL/DTC
- A History DTC will clear after 40 consecutive warm-up cycles have occurred without a malfunction.
- The DTC can be cleared by using a scan tool.

DIAGNOSTIC AIDS
Inspect the following conditions:

IMPORTANT: Remove any debris from the connector surfaces before servicing a component. Inspect the connector gaskets when diagnosing or replacing a component. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion.

- Poor terminal connection-Inspect the harness connectors for backed out terminals, improper mating, broken locks, improperly formed or damaged terminals, and faulty terminal to wire connection. Use a corresponding mating terminal to test for proper tension. Refer to Diagrams.
- Damaged harness-Inspect the wiring harness for damage. If the harness inspection does not reveal a problem, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the scan tool display may indicate the location of the fault. Refer to Diagrams.
- PCM and engine grounds for clean and secure connections

If the DTC is determined to be intermittent, reviewing the Failure Records can be useful in determining when the DTC was last set.