P0504 Lexus Brake Switch Circuit A / B Correlation
Possible causes
– Faulty stop lamp switch
– Blown stop lamp bulb
– Brake switch harness open or shorted
– Brake switch circuit poor electrical connection
– Blown stop lamp bulb
– Brake switch harness open or shorted
– Brake switch circuit poor electrical connection
Symptoms
– Engine Light ON (or Service Engine Soon Warning Light)
P0504 Lexus Description
In addition to turning on the stop lamp, the stop lamp switch signals are used for a variety of engine, transmission, and suspension functions as well as being an input for diagnostic checks. It is important that the switch operates properly, therefore this switch is designed with two complementary signal outputs: STP and ST1.
The Engine Control Module (ECM) analyzes these signal outputs to detect malfunctions in the stop lamp switch.
Lexus Vehicle:Lexus ES,Lexus GS,Lexus GX,Lexus HS,Lexus IS,Lexus LFA,Lexus LS,Lexus LX,Lexus RX,Lexus RX,Lexus SC,Lexus GS350,Lexus GS450H,Lexus IS250,Lexus GX460,Lexus IS350,Lexus LS460,Lexus LS600H,Lexus LX570,Lexus RX350