2018 caddy mk4 error code p0475 &p047F

[Chris_hughes1]

Hi,

just looking for some advice, recently got an engine management light come on warning me about my NOX sensor failing so replaced that with a like for like from VW, I also replaced the lambada sensor for good measure at the same time, ran it for about a week then the engine light came on again this time with the codes P0475 - exhaust pressure control valve A. And another code of P047f - exhaust pressure control valve A stuck open. I bought a new actuator for the valve as from what I could tell the valve was moving freely as by moving it by hand I could hear the exhaust sound drop out (restricting the flow). Having replace the actuator I’ve still got the same codes coming up and every 2/3 start ups the engine management light is back on. Some advice of what to try next would be greatly appreciated.

thanks
Chris

[Sevcon552]

Hi Chris! I Have the same fault code on my caddy. Did you solve your problem? I have replaced the valve on the exhaust, but no luck. Regards Markus

[Chris_hughes1]

Hi mate,

I did end up resolving it, I started by replacing the NOX sensor but turned out for me that wasn’t the issue, I was still getting the light after replacing it.

I ended up taking it to a local vw garage and the checked the wiring from the exhaust valve to the ECU, it had corroded so the repaired it for me and the fault hasn’t come back since.

[Sevcon552]

Hi! Thanks a lot for answering.
The wiring was my next step to go.
I’ll digg in to it and see what I could find