OBD-II code · Powertrain (generic, extended)
P20CB Exhaust Aftertreatment Fuel Injector A Control Circuit/Open
Exhaust Aftertreatment Fuel Injector A Control Circuit/Open: the control circuit is open. 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 P20CB?
Usually safe for short trips, but don’t ignore it: the underlying fault can get more expensive over time.
Common causes
- Most likelyInjector winding open
- PossibleOpen wire to injector
- Less likelyPin pushed back out of connector body
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, Aftertreatment Fuel Pump
Related codes
- P20D1Exhaust Aftertreatment Fuel Injector B Control Circuit/Open
- P20C8Reductant Heater D Control Circuit High
- P20C9Reductant Control Module Requested MIL Illumination
- P20CAReductant Injection Air Pressure Leakage
- P20CCExhaust Aftertreatment Fuel Injector A Control Performance
- P20CDExhaust Aftertreatment Fuel Injector A Control Circuit Low
- P20CEExhaust Aftertreatment Fuel Injector A Control Circuit High
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.