Powertrain, generic (extended)

P2D90 Engine Oil Pressure Sensor/Switch C Circuit High

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2D90 is set when sensor C delivers a voltage above its valid range. Typical reasons are a broken ground or signal wire that lets the input float up, a short to battery voltage or a sensor with a failed output stage. No manufacturer publicly describes P2D90; for the EA888 evo5 Audi documents only the low counterpart P2D8F. Sensor A gives the yardstick: Ford's 2024 engines flag an analog sensor above 4.75 V for 5 s (P0523), and a GM 2024 engine table sets P0523 above 4.5 V after 1 s as a two-trip fault. Because the controller can no longer read real oil pressure from that sensor, it may light the oil warning or hold functions that rely on it, such as a variable oil pump, in a safe setting. Measure reference, signal and ground at the plug first. Low is P2D8F.

Likely causes

Open ground or signal wire of sensor C
Signal wire shorted to battery or reference voltage
Sensor C output stage defective

Symptoms

  • Malfunction indicator lamp, depending on make
  • Oil pressure gauge or warning shows implausible values
  • Variable oil pump may stay in its safe stage

Repair estimate

DifficultyEasyDIY possible
Parts and labour€40–300
Time0.3–1.5 h

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

Parts involved

engine oil pressure sensor cwiring harnessecm

Related codes

P2D8EP2D8FP2D91P0523P055D

References: fordservicecontent.com, gsi.ext.gm.com, law.cornell.edu.