DTC P0571 Stop Light Switch Circuit Malfunction: Description
When the brake pedal is depressed, the stop light switch sends a signal to the ECM.
Receiving the signal, the ECM cancels the cruise control system. Even if there is a malfunction in the stop light signal circuit while the cruise control is in operation, normal driving is maintained due to a fail-safe function. Cruise control is canceled when positive battery voltage is applied to terminal STP.
When the brake pedal is depressed, positive voltage is applied to terminal STP of the ECM through the STOP fuse and the stop light switch, and the ECM cancels the cruise control.
When the brake pedal is released, positive voltage is applied to terminal ST1- of the ECM through the ECU-IG fuse and the stop light switch, and the ECM operates the cruise control.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0571 | Trouble code is output when voltages of terminals ST1- and STP of ECM are both below 1 V for 0.5 sec. or more |
|