P20FEReductant Metering Unit 1 Performance
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- Can trigger limp mode
- Needs a drive cycle to confirm a fix
- How the car detects it
- P20FE judges whether the first reductant metering unit actually delivers the quantity the SCR control asks for. GM's 2025 Duramax tables average a delivery compensation factor and set the code, Type A after one trip, once that factor passes 1.44, meaning the expected pressure drop no longer proves correct dosing. VW Group uses it on 3.0 TDI models: Porsche reflashed 2015–2016 Cayenne Diesel because the check was too sensitive in the cold; Audi tied it on 2012–2015 Q7 to a loose filter housing letting unfiltered AdBlue damage the pressure sensor and pump; VW's 2015 Touareg tip first checks the injector part number, then runs the metering quantity test. GM also updated software for it (23-NA-193, 24-NA-058). Unit 2 is P2EAD.
- What you may notice
- Malfunction indicator lamp on
- AdBlue/DEF system warning in the cluster
- Higher NOx, possible SCR efficiency codes (P20EE)
- Likely causes
- LikelyPartly blocked or crystallised dosing injector
- PossibleLoose or damaged tank filter letting debris reach pump and sensor
- PossibleOver-sensitive diagnostic calibration (software update available)
- RareAir in the dosing lines after service or low fluid level
- 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 – €1,800
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.