P2525
Vacuum Reservoir Pressure Sensor Circuit
Vacuum system
Generic OBD-II
Low
What it means
P2525 means the ECM has detected a circuit problem with the vacuum reservoir pressure sensor. That sensor monitors stored vacuum used by systems such as the brake booster or vacuum-actuated actuators. The fault is usually electrical — the sensor, its wiring, or a connector — so the engine normally runs fine. On vehicles that rely on the reservoir for brake assist, confirm the brake pedal still feels normal.
Low
Can I keep driving? Usually yes — the engine runs normally; if the vacuum reservoir feeds the brake booster, confirm brake-pedal feel is normal.
Common symptoms
What you'll notice
- Check-engine light on
- Often no noticeable driving symptom
- On some vehicles, a firmer brake pedal if vacuum assist drops
- Related vacuum-actuated functions behaving abnormally
Common causes
Most likely first
- Faulty vacuum reservoir pressure sensorLikely
- Open, shorted, or chafed wiring in the sensor circuitCommon
- Corroded or loose connector at the sensorCommon
- Signal or reference voltage problem from the moduleLess often
How to diagnose & fix
Work through it in order
- Scan and read freeze-frame data to see the fault conditions.
- Inspect the reservoir pressure sensor connector and wiring for damage or corrosion.
- Check the sensor's reference and signal voltage at the connector.
- Inspect the vacuum reservoir and hoses for leaks while you are there.
- Replace the sensor if the wiring is good; recheck after repair.
FAQ
Quick answers
Is it safe to drive with P2525?+
Usually yes. It is typically a monitoring-circuit fault with no driving effect. If your vehicle uses the vacuum reservoir for brake assist, make sure the brake pedal still feels firm and normal.
Can I just clear P2525?+
You can, but a faulty sensor or wiring will set it again. Diagnose the circuit first.
Related codes
Often seen with P2525
Read & clear P2525 yourself
Scan your car, confirm the code, and clear it once it's fixed — with OBD DashX on your phone.
✓ Verified name — SAE J2012 / ISO 15031-6Guidance reviewed by OBD DashX