P2495EGR Cooler Bypass Position Sensor Circuit High (Bank 1)
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Needs a drive cycle to confirm a fix
- How the car detects it
- P2495 covers a bank 1 bypass position signal that climbs close to the reference voltage. On GM Duramax diesels the 2017 calibration fails it above 99 % of 5 V in 200 out of 250 samples, with the same enable conditions as the low test, and rates it Type B. In the field GM saw it on 2015 LML-powered full-size pickups: preliminary bulletin PI1449 lists it with P2493, P24C4 and P06A3 and has the whole bypass valve replaced. That combination is a useful hint: a shared 5 V supply fault (P06A3) can drag several sensors along, so check the reference circuit before condemning parts. Otherwise an open ground wire or a signal wire touching supply is typical. Low voltage is P2494, bank 2 P249A.
- What you may notice
- Check engine light after two trips
- Additional sensor supply codes stored at the same time
- Likely causes
- LikelyOpen sensor ground wire
- PossibleDefective bypass valve with integrated sensor
- PossibleFault in the shared 5 V reference circuit
- RareSignal wire touching a voltage source
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €30 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.