I have a 2011 Mercedes C180. The engine no longer runs smoothly after the timing chain was replaced. When I used an OBD scanner, it always showed the error code P3406. This issue did not occur before the timing-chain work, so it is possible that something was incorrectly assembled or out of sync. I am trying to figure out what is causing this misfire, and how to diagnose or fix it.
P3406 Exhaust camshaft positioning actuator – performance or stuck-off
This means that the position of your exhaust camshaft may be different than the recommended value, or it could even stick. This fault can be caused by a number of factors, including a fine adjustment issue, an installation error or a sensor problem.
What is P3406 Trouble Code ?
The P3406 code indicates that the ECU has detected a timing deviation in the exhaust camshaft. This deviation may occur due to a number of reasons, including: Failure of a physical component
Why is the P3406 still occurring after replacing the chain and sprockets?
Timing Error (1-2 Tooth Misalignment)
The engine will still run if there is a misalignment of 1-2 teeth in the synchronisation of the crankshaft with the camshaft when installing the chain, but the ECU detects this discrepancy.
The sensors will still measure the discrepancy after a few thousands kilometres, and then generate the code P3406.
Incompatible Gear (Use Poor-Quality Aftermarket Gears)
Some aftermarket brands, such as Swag, do not always work in synchronisation with Mercedes ECU.
The error is repeated when the gear tooth structure, internal system of springs, or rebound movement are not recognized as original.
Camshaft Position Sensor Failure
If the sensor is measuring incorrectly, even if timing is correct, P3406 will be displayed.
The ECU misinterprets shaft position and sees it as a “performance problem”.
Failure of the solenoid valve on VVT
If this component is not working or blocked, it can cause the camshaft to malfunction.
Engine Oil Pressure and Quality
The VVT system is operated by oil pressure. This system will not respond properly or on time if the oil viscosity, channels, or pressure are low.
What should be done?
Frequently Asked Questions about P3406
What is the fault code P3406?
Why does the P3406 error persist after replacing the chain?
Does P3406 affect engine performance?
Is P3406 a result of a faulty camshaft position sensors?
It is most likely a sensor or setting that’s causing the problem
If the P3406 error persists despite replacing the chain and sprocket, it indicates that there is a problem with the application, sensor or timing accuracy, rather than the component itself.
Recommendation:
I thought I cannot solve this problem myself after reading your answer and I took my car to another workshop. They told me that there’s a synchronization problem with the timing belt and components. So he solve the problem and I sent the bill to previous workshop since it was their fault and I don’t trust them anymore.