P0504 Audi 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 Audi 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.
Audi Vehicle:Audi A1,Audi A3,Audi A1,Audi A3,Audi A1,Audi A3,Audi A4,Audi A5,Audi Q3,Audi A5,Audi Q5,Audi A3,Audi A4,Audi A5,Audi TT,Audi Q3,Audi Q5,Audi S3,Audi TTS,Audi RS 3,Audi TT RS,Audi A7,Audi Q7,Audi A8,Audi A6,Audi S4,Audi S5,Audi Q5,Audi S6,Audi S8,Audi S5,Audi A8,Audi R8 V8,Audi RS 5,Audi S6,Audi R8 V10,Audi R8 GT,Audi A8L