OBD-II code · Powertrain (generic, extended)
P20D3 Exhaust Aftertreatment Fuel Injector B Control Circuit Low
Exhaust Aftertreatment Fuel Injector B Control Circuit Low: the control-circuit voltage is below the expected range. This injector doses fuel into the exhaust to raise temperature for diesel particulate-filter regeneration; it does not fuel the engine.
Is it safe to drive with P20D3?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyShort to ground
- Less likelyConnector pins corroded - high contact resistance
- Less likelyHarness chafing through insulation
Symptoms
- Check engine light on
- Misfire or rough idle on the affected cylinder
- Increased fuel consumption
- Possible fuel smell or smoke from exhaust
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
- Aftertreatment Fuel Injector
Related codes
- P20CDExhaust Aftertreatment Fuel Injector A Control Circuit Low
- P20D0Exhaust Aftertreatment Fuel Injector A Stuck Closed
- P20D1Exhaust Aftertreatment Fuel Injector B Control Circuit/Open
- P20D2Exhaust Aftertreatment Fuel Injector B Control Performance
- P20D4Exhaust Aftertreatment Fuel Injector B Control Circuit High
- P20D5Exhaust Aftertreatment Fuel Injector B Stuck Open
- P20D6Exhaust Aftertreatment Fuel Injector B Stuck Closed
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.