DTC P0703-12: Brake Switch "B" Circuit Short to Battery [04/2018 -]: Description

WARNING: This page is about a different car, the 2022 Toyota Avalon, 2021 Toyota Avalon, 2020 Toyota Avalon, and 2019 Toyota Avalon. However, it is still accessible from the selected car via links, so may be relevant.

The purpose of the stop light switch signal circuit is to prevent the engine from stalling when the brakes are suddenly applied while driving in the lock-up condition.

When the brake pedal is depressed, the stop light switch assembly sends a signal to the ECM. The ECM then cancels the operation of the lock-up clutch while braking is in progress.

DTC No.	Detection Item	DTC Detection Condition	Trouble Area	MIL	Memory	Note
P0703-12	Brake Switch "B" Circuit Short to Battery	All of the following conditions are met (2-trip detection logic): The engine switch is on (IG). The battery voltage is 8 V or more. The stop light switch remains ON while the vehicle is driven in a GO (30 km/h (19 mph) or more) and STOP (less than 3 km/h (2 mph)) pattern 5 times.	Stop light switch assembly Short in stop light switch signal circuit ECM	Comes on	DTC stored	SAE Code: P0724