Powertrain, generic (extended)

P2527 Vacuum Reservoir Pressure Sensor Circuit Low

Check engine lightOn

EmissionsRelevant

Drive cycleNot required

Limp modePossible

P2527 means the signal from the vacuum reservoir pressure sensor has fallen below the lowest voltage a working sensor can produce. Whether low volts stand for deep vacuum or for atmospheric pressure depends on the sensor curve, but a reading at the floor is treated as an electrical fault, not as a vacuum value. Likely causes are a signal line shorted to ground, an open line on a sensor with pull-down, a missing 5 V reference, or a dead sensor. The 2004–2006 Dodge Sprinter is the documented case: FCA's emissions recall T21 names P2527 among the codes that may appear once the corrected engine software is installed; voltage thresholds were not published. P2528 is the high-side counterpart, P2526 a plausible voltage with an implausible value. Vacuum actuators may then run open-loop.

Likely causes

Signal wire shorted to ground

5 V reference open or pulled down

Sensor without output

Symptoms

Check engine light
Boost or EGR control in default mode, less power

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

P2525 P2526 P2528 P2529

References: static.nhtsa.gov, law.cornell.edu, en.wikipedia.org.