P0571

Schematic:

CIRCUIT DESCRIPTION
The cruise control brake switch and the cruise clutch switch are normally closed switches. When the Cruise Brake switch or the cruise clutch switch are closed, the PCM senses ignition voltage on the cruise control release signal circuit. The PCM compares this signal to the signal received from the other clutch and brake switches. If these switches do not agree this DTC will set.

CONDITIONS FOR RUNNING THE DTC
^ The engine speed is more than 1000 RPM for 1 second.
^ The wheel speed is more than 20 mph in order to enable the diagnostic. The diagnostic disables when the wheel speed is less than 5 mph.

CONDITIONS FOR SETTING THE DTC
^ The vehicle speed decreases 1 MPH in 0.5 seconds without the PCM sensing a switch transition.
^ The condition is present for 10 accel/decel cycles.

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
Perform the following in order to adjust the cruise control brake switch:
1. With the brake pedal depressed, insert the cruise control brake switch into the retainer until the switch body seats in the retainer. You can hear clicks as you push the threaded portion of the switch through the retainer.
2. Slowly pull the brake pedal fully rearward against the stop until you can no longer hear the clicks.

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

TEST DESCRIPTION

Steps 1 - 12:

Steps 13 - 28:

The numbers below refer to the step numbers on the diagnostic table.
2. This step determines if the fault is present.
4. This step tests for a cruise control release circuit for a short to B+.