P2D23Turbocharger Interstage Pressure Sensor A Circuit Low
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- How the car detects it
- P2D23 says the interstage pressure signal sits below the lowest voltage a working sensor can produce. Typical causes are a signal wire shorted to ground, a lost 5 V supply or an internal sensor short. No public table gives a threshold for this sensor; for comparison, Ford's 2023 diesels treat a DEF pressure sensor below 0.2 V as circuit low. The sensor itself sits between the two compressors of a series turbo system, as GM's two-stage control patent describes, where its value guides the low-pressure stage. California requires out-of-range checks on every such input. With the value missing, the controller usually falls back to a model and caps boost. A high reading is P2D24.
- What you may notice
- Check engine light
- Boost limited, noticeably less power
- Further codes if the shared sensor supply is affected
- Likely causes
- LikelySignal wire shorted to ground
- Possible5 V reference open or pulled down by another sensor
- PossibleSensor shorted internally
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Usually a job for a workshop.Typical cost: €80 – €600
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.