What does it mean?
P1913 is a Powertrain (engine, transmission, fuel system) fault code. It indicates: Brake Booster Pressure Sensor Short Circuit to Ground .
Symptoms
- Malfunction indicator lamp on with a brake booster or brake assist warning
- Increased pedal effort or a firm pedal, sometimes only when cold or after repeated stops
- Electric vacuum pump behaviour becomes wrong — running continuously or staying off
- Stop-start disabled and cruise control unavailable
- Warning messages relating to the brake system appear on the dash
- Symptoms can be intermittent and worse after rain or washing
Likely causes
- Signal wire chafed against the body or a bracket and grounding out
- Water inside the sensor connector bridging the signal pin to the ground pin
- Internally shorted sensor holding its output at ground
- Harness pinched under a bracket, trim or the engine cover
- Damaged or corroded terminal in the sensor or module connector
- Loss of the 5 V reference feeding the sensor so the output collapses
- Faulty input circuit in the control module
How to fix it
- Read the freeze frame data and observe the sensor value in live data
- Unplug the sensor: if the signal rises toward reference voltage, the sensor is at fault; if it stays at ground, the wiring is shorted
- Check the sensor connector for water and corrosion and confirm terminal fit
- Inspect the harness route for pinch points under brackets, trim and the engine cover
- Measure the 5 V reference and ground at the connector with the key on
- Confirm with a vacuum gauge that the booster and check valve are genuinely healthy, so a real low-vacuum condition is not being masked
- Repair the shorted wiring or replace the sensor; replace the module only after everything else tests good