P248FEGR Cooler Bypass Control Circuit Range/Performance (Bank 2)
- 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
- With P248F the bank 2 bypass circuit is electrically sound, yet the flap does not do what the controller asks: it lags behind the setpoint, stops short of its end position or switching shows no effect on the gas temperature after the cooler. No manufacturer publishes a bank 2 version of this check. On bank 1 (P245B) GM's 2017 Duramax logic compares commanded and measured flap position and fails above a 16 % deviation, while Ford's 2023 diesels move the flap on purpose and expect a clear temperature response. A second bank would be judged the same way. Sticking from soot and oil carbon, a tired return spring, weak vacuum on pneumatic versions or wrong position feedback are the usual reasons. If the flap is later found fixed in place, the stuck code P24A6 may follow.
- What you may notice
- Check engine light on
- Often no noticeable change in driving
- Likely causes
- LikelyBypass flap on bank 2 sluggish from soot and carbon
- PossibleLeaking vacuum line or weak vacuum on pneumatic actuators
- PossibleBank 2 position feedback reading off
- 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: €100 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.