P1574

Schematic:

CIRCUIT DESCRIPTION
The stop lamp switch (TAC brake switch) is a normally open switch. When the switch is closed, the TAC module senses ignition voltage on the signal circuit. If the PCM senses a high rate of deceleration without a input from this switch this DTC will set.

CONDITIONS FOR RUNNING THE DTC
^ The engine speed is more than 1000 RPM.
^ The wheel speed must be more than 20 MPH in order to enable the diagnostic. The diagnostic will disable when the wheel speed is less than 5 MPH.

CONDITIONS FOR SETTING THE DTC
^ The vehicle speed decreases 0.5 MPH in 0.5 seconds without the PCM sensing a switch transition.
^ The condition is present for 20 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.

Steps 1 - 15:

Steps 16 - 21:

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
In order to adjust the stop lamp switch perform the following:
1. With the brake pedal depressed, insert the brake lamp 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.