P1571

Schematic:

CIRCUIT DESCRIPTION
The PCM supplies 5 volts on the desired torque circuit to the Electronic Brake And Traction Control Module (EBTCM). The EBTCM toggles this 5 volt signal to a ground in order to produce a duty cycle signal. The signal is proportional to the amount of engine output torque reduction requested by the EBTCM. The EBTCM supplies this signal when it detects a wheel slip. In order to reduce engine output torque, the PCM reduces the amount of spark advance and in some cases, the PCM disables a number of fuel injectors. This diagnostic test checks for a desired torque signal failure. If the PCM does not receive the desired torque signal, this DTC sets.

CONDITIONS FOR RUNNING THE DTC
^ The traction control has not failed.
^ The engine speed is more than 500 RPM for 20 seconds.

CONDITIONS FOR SETTING THE DTC
The desired torque signal is not received by the PCM for 3 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

IMPORTANT: Do not perform this diagnostic procedure if the customers concern is not related to the ABS and/or the Traction Control systems.

The following may cause an intermittent; Inspect for the following:

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 Testing for Intermittent and Poor Connections and Connector Repairs in Diagrams.
^ Damaged harness.
Inspect the wiring harness for damage. If the harness appears to be OK, observe the display on the scan tool while moving connectors and wiring harnesses related to the sensor. A change in the display may indicate the location of the fault. Refer to Wiring Repairs in Diagrams.
^ Inspect the PCM and the engine grounds for clean and secure connections.

If the DTC is determined to 6e intermittent, reviewing the Failure Records can be useful in determining when the DTC was last set.

TEST DESCRIPTION

Diagnostic Chart:

The numbers below refer to the step numbers on the diagnostic table.
2. This step determines if the EBTCM is receiving the 5.0 volts from the PCM. Use the connector test kit adaptor when probing the EBTCM connector.
3. If no DTCs are set, inspect connections at the EBTCM.
11. This DTC will not report a pass. The scan tool status for this DTC will never report a pass. The scan tool will only display when the diagnostic fails. The repair is not complete if the scan tool indicates that the diagnostic ran and failed.