P26FBEGR Cooler Bypass Control Stuck Closed (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
- A diesel engine routes recirculated exhaust around the EGR cooler while it is cold, so that the gas warms the engine and aftertreatment; later the bypass flap closes and the gas passes through the cooler. P26FB means the bypass on bank 1 does not open when commanded and stays in the closed, cooling position. FCA uses the code on the 3.0 L EcoDiesel (Ram 1500 2020, Jeep Wrangler). STAR case S2018000001 links it to a 0.6 mm brass restrictor that clogs inside the vacuum line running from the remote solenoid to the flap actuator; the tube must be replaced rather than cleaned, and the actuator is checked by hand for sticking. FCA's PCM software bulletins 18-008-21 and 18-002-23 list P26FB among the codes they address. CARB lists the bypass among parts that must respond during cold-start strategies, so warm-up emissions rise.
- What you may notice
- Check engine light on
- Longer warm-up of engine and exhaust aftertreatment
- Usually no noticeable change in driveability
- Likely causes
- LikelyBlocked orifice or kinked vacuum line to the bypass actuator
- PossibleBypass flap sticking from soot and deposits
- PossibleFaulty vacuum solenoid or weak vacuum supply
- RareOutdated PCM calibration with too sensitive detection
- 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: €50 – €1,500
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.