P1571

Diagnostic Chart (Part 1 Of 2):

Diagnostic Chart (Part 2 Of 2):

Schematic:

CIRCUIT DESCRIPTION
The traction control system 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 traction control system reduces engine torque by any or all of the following methods:
^ Retarding spark timing
^ Altering air/fuel ratio
^ Altering boost PWM (VIN 1)
^ Shutting OFF up to three injectors

To determine the amount of torque reduction required, the PCM monitors the TCS Desired Torque PWM signal from the Electronic Brake and Module (EBCM).The PCM also provides a TCS Delivered Torque PWM informing the EBCM 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 EBCM. With traction control not active, Desired Torque should vary between 99-100 percent. The Desired Torque display on the scan tool is not the PWM duty cycle.

CONDITIONS FOR SETTING THE DTC
^ Desired torque signal PWM duty cycle is less than 5 percent or more than 95 percent.
^ The conditions exists for up to 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
An intermittent may be caused by a poor connection, rubbed through wire insulation, or a broken wire inside the insulation. Inspect for the following conditions:
Intermittent Test - Using a scan tool, observe Desired Torque display while moving related connectors and wiring harness. If the failure is induced, the displayed value will change. This may help to isolate the location of the malfunction.

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
^ 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.
^ 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.

TEST DESCRIPTION
The numbers below refer to the step numbers on the diagnostic table.
10. This vehicle is equipped with a PCM which utilizes an Electrically Erasable Programmable Read Only Memory (EEPROM). When the PCM is being replaced, the new PCM must be programmed.