A fault code doesn’t yet mean the unit or sensor itself is faulty: often it’s the plug and connector leading to it.
Possible causes
- Valve connector or wiring
- The flap is seized with soot or rust
- Flap actuator
- ECU (rarely)
What you can do yourself
- Some diesels have this flap: it speeds up warm-up in winter and acts as an exhaust brake on trucks. Check its connector and movement.
- If the flap is stuck closed, the engine loses power and runs hot — don’t drive like this for long.
Stop and don’t drive on if:
- The Check Engine light is flashing
- The temperature gauge is in the red or the overheating light is on
- The red oil pressure light is on
- Smoke from under the bonnet, a burning or petrol smell
- Strong jerking, knocking from the engine, or the car barely moves
OOleg’s tip: check the connector
Often the cause is simple — there is no contact in the connector (plug). Look at the connector from the back: remove the rubber seal and you will see whether a wire is corroded or has come off completely. Corrosion shows up as green deposits. Ideally, gently pull each wire towards you one at a time: a sound wire stays in place, while a corroded one simply comes off — it needs to be repaired.
Unplug and inspect connectors with the ignition off.
The explanation comes from the error code reference in the AvtoElektrik PRO app.