Powertrain, generic (extended)

P2525 Vacuum Reservoir Pressure Sensor Circuit

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modePossible

P2525 is the general circuit fault of the pressure sensor on a vacuum reservoir. Diesels, and many hybrids and electric drives, lack usable intake vacuum and run a separate pump, often driven from the camshaft or by an electric motor, that fills a reservoir. That stored vacuum serves the brake booster and, on many diesels, pneumatic actuators for EGR, turbocharger control, swirl flaps or an exhaust brake. The sensor, normally a three-wire part with 5 V reference, lets the engine module verify the supply. CARB counts such inputs among comprehensive components that need circuit checks whenever they can affect emissions or other monitors. No maker documents P2525 itself. P2526 to P2529 split out plausibility, low, high and intermittent faults. Actuators may fall back to defaults.

Likely causes

Sensor wiring open or connector loose
Reservoir pressure sensor defective
Shared 5 V reference disturbed by another sensor

Symptoms

  • Check engine light depending on maker
  • Reduced boost or EGR function in default mode

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€50–350
Time0.5–2 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

vacuum reservoir pressure sensorsensor wiring

Related codes

P2526P2527P2528P2529

References: law.cornell.edu, en.wikipedia.org.