DTC P0571: Stop Light Switch Circuit Malfunction [08/2015 - 08/2019]: Description
WARNING: This page is about a different car, the 2019 Toyota 4Runner, 2018 Toyota 4Runner, 2017 Toyota 4Runner, and 2016 Toyota 4Runner. However, it is still accessible from the selected car via links, so may be relevant.
When the brake pedal is depressed, the stop light switch sends a signal to the ECM. Upon receiving the signal, the ECM cancels cruise control. Even if there is a malfunction in the stop light signal circuit while cruise control is in operation, normal driving is maintained due to a fail-safe function.
When the brake pedal is depressed, positive voltage is applied to terminal STP of the ECM through the STOP fuse and stop light switch, and the ECM cancels cruise control.
| DTC Code | DTC Detection Condition | Trouble Area |
|---|---|---|
| P0571 | The voltages of terminals ST1- and STP of the ECM are both below 1 V for 0.5 seconds or more. |
|