OBD-II code · Powertrain (generic, extended)
P201A Reductant Injection Valve Circuit Range/Performance (Bank 2 Unit 1)
Reductant Injection Valve Circuit Range/Performance (Bank 2 Unit 1): the signal is implausible or outside the valid range. This valve doses reductant (DEF/AdBlue) into the exhaust for SCR NOx reduction.
Is it safe to drive with P201A?
The car may go into limp mode (reduced power). Get it diagnosed before a long trip.
Common causes
- Most likelyDEF crystallisation clogs the dosing nozzle
- PossibleDEF supply pressure below target
- PossibleValve coil ageing — slow response
Symptoms
- Check engine light or NOx warning on
- AdBlue/DEF level or quality warning
- Possible no-start countdown after ignore period
- Failed emissions inspection (NOx)
Repair at a glance
- Difficulty
- Hard
- DIY friendly
- Best left to a mechanic
- Typical labour
- 1–4 h
- Emissions test
- Likely to fail
- Parts involved
- Reductant Injection Valve, Reductant Metering Unit, Scr Catalyst
Related codes
- P202EReductant Injection Valve Circuit Range/Performance (Bank 1 Unit 1)
- P2017Intake Manifold Runner Position Sensor/Switch Circuit High (Bank 1)
- P2018Intake Manifold Runner Position Sensor/Switch Circuit Open (Bank 2)
- P2019Intake Manifold Runner Position Sensor/Switch Range/Performance (Bank 2)
- P201BIntake Manifold Runner Control Actuator Supply Voltage Low (Bank 1)
- P201CIntake Manifold Runner Control Actuator Supply Voltage Low (Bank 2)
- P201DIntake Manifold Runner Control Actuator Internal Performance (Bank 1)
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.