P248F code meaning
EGR Cooler Bypass Control Circuit Range/Performance (Bank 2)
Powertrain system Generic code P24xx codes Check engine light
What P248F means
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.
P248F at a glance
- Check engine lightYes, usually on
- Emissions testCan fail
- Limp modeNot expected
- Repair difficultyMedium
- Typical labor0.5 to 4 hours
- Clears after repairAfter a drive cycle
Symptoms of P248F
- Check engine light on
- Often no noticeable change in driving
Common causes of P248F
- Most 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
Check the most likely causes first. Replacing parts by guesswork is the most expensive way to clear a code.
Parts involved
EGR cooler bypass valve b2
What each part of P248F means
| P | Powertrain system: engine, fuel system, ignition, emissions and transmission. |
| 2 | Generic code (second SAE range): it means the same on every make. |
| 4 | Area: auxiliary emission controls (catalytic converter, EGR, EVAP). |
| 8F | The exact fault in that area. |
What to do next
- Note P248F and any other codes stored with it: several codes together often point to one cause.
- Check for loose connectors and damaged wiring around the parts the code names.
- Check open recalls for your car: some faults are fixed for free by the dealer. Enter your VIN.
- Clear the code only after the repair. If it comes back, the fault is still there.
Buying a used car? Scan it for stored codes before you pay. A recently cleared memory can hide a problem.
Questions about P248F
What does P248F mean?
P248F means "EGR Cooler Bypass Control Circuit Range/Performance (Bank 2)". 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. It is a generic code, so it means the same on every make.
Is it safe to drive with P248F?
Usually yes, for a short time, if the check engine light is steady and the car drives normally. If the light flashes or the car runs badly, stop and have it checked.
Will P248F fail an emissions test?
Yes, it can. P248F is emissions-related, so most inspection programs fail a car while it is stored or while the check engine light is on.
How hard is P248F to fix?
Difficulty: medium. A typical repair takes 0.5 to 4 hours of work. This is a job for a workshop.
Will P248F clear itself after the repair?
After the repair the car has to complete a drive cycle (a mix of city and highway driving) before the test runs again. Until then the readiness monitor shows "not ready", which can fail an inspection.