OBD-II code · Powertrain (generic)
P05F3 Exhaust Aftertreatment Power Relay Control Circuit Open
The power relay that supplies the entire exhaust aftertreatment system (DOC, DPF, SCR sensors and heaters) reports an open control circuit. Aftertreatment effectively goes offline.
Is it safe to drive with P05F3?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyOpen in relay control or harness
- Less likelyPin pushed back out of connector body
- Less likelyCracked solder joint inside the module or sensor
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–1.8 h
- Emissions test
- Likely to fail
- Parts involved
- Aftertreatment Power Relay
Related codes
- P05F0Reductant Pump Supply Voltage Circuit High
- P05F1Reductant Pump Supply Voltage Circuit Stuck On
- P05F2Reductant Pump Supply Voltage Circuit Stuck Off
- P05F4Exhaust Aftertreatment Power Relay Control Circuit Low
- P05F5Exhaust Aftertreatment Power Relay Control Circuit High
- P05F6Exhaust Aftertreatment Power Relay Control Circuit Stuck On
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.