Powertrain
generic / SAE
P0078
Exhaust Valve Control Solenoid Circuit Bank 1
Generic electrical fault on the exhaust-valve control solenoid for bank 1. The exhaust control valve modulates exhaust backpressure or routing (EGR feed, sound, regen support); a malfunction shifts torque mapping and may trigger limp mode.
SystemPowertrain
Typegeneric / SAE
GroupP0
Range / number– / 78
Possible causes
- Solenoid coil failed high
Inspection / repair
- Difficulty: medium
- DIY: possible
- Estimated cost: 80–500 €
- Estimated time: 0.5–3 h
- Component: exhaust valve solenoid
- Component: solenoid wiring
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012