VOLVO
ECM-P070300 - Brake Switch B Input Circuit. General Failure Information. No sub type information
System
Engine Control Module (ECM)
Volvo models this fault code applies to
Applies to the following models:
2 modelsS80 (2007–), V70 (2008–)
Show models by year and engine (2)
What does this fault code mean?
The engine control module monitors the brake light signal and the brake pedal sensor. The code is set when there is interference on the brake light signal, or when the brake pedal sensor is activated without a corresponding brake light signal.
Possible causes
- Open circuit in the signal wire from the brake light switch
- Damaged brake light switch
- Damaged brake pedal sensor
What you can do
- 1Read and clear the fault code, and test-drive to see whether it returns
- 2Check that the brake lights come on when you press the brake pedal and go out when you release it
- 3Look at the connector at the brake light switch and the wire for loose contacts, oxidation and chafing
- 4Use a multimeter to check that the signal wire from the brake light switch is not broken, with the connectors disconnected
- 5The fault concerns the braking system. If the fault remains, have a workshop correct it without delay, since the brake lights matter to other road users
Symptoms you may notice1
- No noticeable symptoms for the driver
General guidance for car owners. Diagnosis on the car can point to a different cause.