DTC P0571

Circuit Description

The TCC Brake (cruise release) switch is a normally closed switch. When the TCC Brake switch is closed, (brake pedal released) the PCM senses ignition voltage on the TCC Brake switch signal circuit.

If the PCM senses a voltage on the TCC Brake switch signal circuit when the TCC Brake switch should be open, this DTC sets.

Conditions for Running the DTC

The engine speed is greater than 700 RPM.
The engine operates for greater than 2 seconds.
The wheel speed is greater than 48 km/h (30 mph) in order to enable the diagnostic. The diagnostic disables when the wheel speed is below 16 km/h (10 mph).

Conditions for Setting the DTC

The PCM detects voltage on the TCC Brake switch circuit when the TCC Brake switch should be open.
All above conditions are present for 1.5 seconds.

Action Taken When the DTC Sets

The powertrain control module (PCM) stores the DTC information into memory when the diagnostic runs and fails.
The malfunction indicator lamp (MIL) will not illuminate.
The PCM records the operating conditions at the time the diagnostic fails. The PCM stores this information in the Failure Records.

Conditions for Clearing the DTC

A last test failed, or current DTC, clears when the diagnostic runs and does not fail.
A history DTC will clear after 40 consecutive warm-up cycles, if no failures are reported by this or any other non-emission related diagnostic.
Use a scan tool in order to clear the DTC.

Diagnostic Aids

Remove any debris from the PCM connector surfaces before servicing the PCM. Inspect the PCM connector gaskets when diagnosing/replacing the modules. Ensure that the gaskets are installed correctly. The gaskets prevent contaminate intrusion into the PCM.
For any test that requires probing the PCM or a component harness connector, use the Connector Test Adapter Kit J 35616-A . Using this kit prevents damage to the harness/component terminals. Refer to Using Connector Test Adapters in Wiring Systems.
Test drive the vehicle if a switch or circuit condition cannot be located. An intermittent condition may be duplicated during a test drive.
For the TCC Brake switch adjustment refer to Stop Lamp Switch Adjustment in Hydraulic Brakes.
For an intermittent, refer to Testing for Intermittent and Poor Connections in Wiring Systems.

Test Description

The number below refers to the step number on the diagnostic table.

This step determines if the fault is present.

Step	Action	Yes	No
Schematic Reference: Cruise Control Schematics
1	Did you perform A Diagnostic System Check - Cruise Control?	Go to Step 2	Go to Diagnostic System Check - Cruise Control
2	Connect a scan tool. Turn ON the ignition, with the engine OFF. Monitor the TCC Brake switch parameter in the PCM data list. Does the brake switch parameter indicate Applied?	Go to Step 3	Go to Diagnostic Aids
3	Turn OFF the ignition. Disconnect the TCC Brake switch. Turn ON the ignition, with the engine OFF. Observe the TCC Brake switch parameter in the PCM data list. Does the TCC Brake switch parameter indicate Released?	Go to Step 5	Go to Step 4
4	Test the TCC Brake switch signal circuit for a short to voltage. Did you find and correct the condition?	Go to Step 10	Go to Step 7
5	Inspect the TCC Brake switch for proper adjustment. Refer to Stop Lamp Switch Adjustment in Hydraulic Brakes. Did you find and correct the condition?	Go to Step 10	Go to Step 6
6	Inspect for poor connections at the harness connector of the TCC Brake switch. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 10	Go to Step 8
7	Inspect for poor connections at the harness connector of the PCM. Refer to Testing for Intermittent and Poor Connections and Connector Repairs in Wiring Systems. Did you find and correct the condition?	Go to Step 10	Go to Step 9
8	Replace the TCC Brake switch. Refer to Stop Lamp Switch Replacement in Hydraulic Brakes. Did you complete the replacement?	Go to Step 10	--
9	Important Program the replacement PCM. Refer to Powertrain Control Module (PCM) Programming in Engine Controls. Replace the PCM. Refer to Powertrain Control Module (PCM) Replacement in Engine Controls-3.8L or Powertrain Control Module (PCM) Replacement in Engine Controls-5.7L. Is the action complete?	Go to Step 10	--
10	Use a scan tool in order to clear the DTCs. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text. Does the DTC reset?	Go to Step 2	System OK