OBD-II code · Powertrain (generic)
P0477 Exhaust Pressure Control Valve A Low
Exhaust pressure control valve A drive line stuck low — short to ground.
Is it safe to drive with P0477?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyShort to ground
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Best left to a mechanic
- Typical labour
- 0.7–3 h
- Emissions test
- Likely to fail
- Parts involved
- Exhaust Pressure Regulator
Related codes
- P0475Exhaust Pressure Control Valve A
- P04A1Exhaust Pressure Control Valve B Low
- P0474Exhaust Pressure Sensor A Circuit Intermittent/Erratic
- P0476Exhaust Pressure Control Valve A Range/Performance
- P0478Exhaust Pressure Control Valve A High
- P0479Exhaust Pressure Control Valve A Intermittent
- P047AExhaust Pressure Sensor B Circuit
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.