P026DFuel Injection Quantity A Higher Than Expected
- 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
- From 2010, CARB requires diesel engines to detect when the commanded injection quantity is not delivered. The module estimates the fuel actually burned from airflow and the measured lambda (from the NOx or oxygen sensor) and corrects the quantity; if that correction passes a limit, the code sets. P026D means the engine gets more fuel than commanded. GM's LML diesel sets it at idle at a correction of +16 to +35 mm³ per stroke for 12 s, two trips. Volvo trucks detect it as too little oxygen at the NOx sensors for the fuel flow and point to boost sensor, EGR valve and sensor, wrong injectors, turbo vanes and intake leaks. On GM's 2.8 litre diesel vans of 2020–2022 it could also be a software anomaly without driving problems. Symptoms are black smoke and more frequent filter regeneration.
- What you may notice
- Check engine light on
- Black smoke, higher soot load, more frequent filter regeneration
- Rough running or idle
- Often nothing noticeable while driving
- Likely causes
- LikelyInjector dripping or worn, or wrong injector type fitted
- PossibleEGR valve not closing or EGR differential pressure sensor wrong
- PossibleBoost sensor or turbo vanes faulty, intake leak
- PossibleNOx or oxygen sensor reading wrong
- RareSoftware
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Hard · Usually a job for a workshop.Typical cost: €100 – €4,000
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.