P340DDeactivation/Exhaust Valve Control Circuit Bank 2
- Generic OBD-II code · Powertrain
- Turns on the check-engine light
- Matters for the ITP
- How the car detects it
- P340D is the bank 2 version of the exhaust-side group circuit: the engine computer sees an electrical fault on the line that is supposed to disable the exhaust valves of the bank without cylinder 1. No manufacturer documents this code publicly. Separate exhaust control matters because a cylinder can only act as a gas spring if its exhaust valves stay shut too; a Ford patent shows how an exhaust valve that keeps opening can be detected from exhaust pressure. On known engines, though, intake and exhaust are switched together per cylinder, as with GM's DFM. CARB rules call for monitoring of outputs like this one. Related: P340C for bank 1, P340B for the bank 2 intake side, P341D for the function check. Deactivation stays off.
- What you may notice
- Check engine lamp on
- Engine no longer drops cylinders at light load
- Likely causes
- PossibleDamaged wiring to the bank 2 exhaust deactivation actuator
- PossibleFaulty coil in the bank 2 exhaust actuator
- RareOutput stage fault in the engine control module
- Inspection (ITP)
- Matters for the ITP. While the check-engine light is on, the car fails the emissions check.
- Repair
- Medium · Often possible to do yourself.Typical cost: €60 – €900
- Related codes
Explanation from obdex (CC0), exactly as the app shows it. Guidance only; confirm with a workshop.