P2D90Engine Oil Pressure Sensor/Switch C Circuit High
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- 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.
- What you may notice
- Malfunction indicator lamp, depending on make
- Oil pressure gauge or warning shows implausible values
- Variable oil pump may stay in its safe stage
- Likely causes
- LikelyOpen ground or signal wire of sensor C
- PossibleSignal wire shorted to battery or reference voltage
- PossibleSensor C output stage defective
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Easy · Often possible to do yourself.Typical cost: €40 – €300
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.