EPC Light on (intermittently)

[GunnerCP]

Hi guys, looking for some wisdom!

Leon st 1.8tsi dsg 64 plate

Car is due mot in 5 days, the epc light comes on when started from cold most of the time, when warm maybe 3 out of 10 times. It's having a full service and mot at a random garage tomorrow due to time, I left it too late to book in at my usual.

I took it to get it fault scanned at came up with 2 codes P256300 and P034100. They said they will start with the cheapest option first for resolution.

I've googled all sorts and read anything from brake sensor to new turbo (actuator problems or something sticking?). Obviously a new turbo is not at all going to cheap.

The car drives fine when the light is on, no noticable power loss or any other side effects.

I'm not sure how clued up the garage are so are there any pointers anyone can offer or parts to check which can lead to said faults? The car has done about 45k I think from memory and certainly due a service.

 

[Woody_72]

Have a read of this. The other code suggests an issue with the camshaft position sensor.

 

[DaveS]

Picking up this old thread, I have a similar issue. My car is a 64 plate petrol 1.8tfsi with 101,000 miles and has no modifications. About 6 months ago the EPC light come on with a cold start. From OBD11 the code was P256300. No problems noticed when driving. Several weeks later it happened again. Over time it has become more frequent with it now happening more than 50% of the time on start. It is only ever on a cold start. It will always clear if I stop the engine and restart, even when cold. It never appears once the engine is running and never affects the driving, other than stop/start being unavailable when the EPC light is on. No other engine faults are recorded in OBD11.

Having read a few things, I checked engine live data in OBD11. The value 'Charge air pressure control valve uncond voltage sensor' shows 4.4824V. Apparently it should be close to 3.6V.

I did ask my independent dealer to have a look in December but the fault did not show up for them. They said they used some cleaner on the turbo.

Any suggestions for what I should do first? I did read about recalibrating the 'Wastegate Actuator' to correct the voltage shown above. I don't want to touch anything unless it is the right thing to do!