I took my 2015 V60 D4 VEA for the melting plastic inlet manifold recall. The car was apparently working fine with no warnings. The main dealer told me an ECM software update had been performed. On the way home up came the check engine lamp. So back to the main dealer. "Yes sir, shall we book it in for diagnostics, that will be £100" (and loads more to actually fix it). Not likely I thought, as they apparently broke it. So after a little more coaxing and unofficially off the record they admitted that the software update had probably adjusted various thresholds so that my engine was now deemed to be in error. Both they and Volvo must have know that this was a likely outcome of the software upgrade - so shame on both.
Anyway how to fix my car without spending £1000s at Volvo?
So the first stop seemed to be my usual mechanic to see which fault codes were present. This produced fault code P04D9 Closed loop for EGR, limit reached - low flow detected. Which in English means the EGR is bunged-up with soot or jammed. My mechanic showed me a video of a very nice Polish? mechanic fixing the problem, thanks to him:
https://www.youtube.com/watch?v=5zz6qefBV08
So easy I even considered doing it myself but thought better let the expert do it. A little while later, with the EGR dismantled the problem was revealed, the EGR cooler was completely blocked with soot. At this point Volvo would want £100s for a replacement cooler, but as in the video my mechanic cleaned the cooler back to shiny. The rest of the EGR and pipes all got checked and cleaned too. So with the car reassembled and the fault code cleared was the car fixed? Yes, for a short while, then the next problem.
The next problem was a slight engine shudder at low revs in 2nd and 3rd gears. Then the message "Reduced engine performance" with a picture of a tortoise. So back to my mechanic for more fault code reading. This time it was P00BC low MAF (Mass Air Flow). Which in English means not enough air being drawn into the engine. All the airways were checked and found to be clear. A very sooty sensor on the inlet manifold was cleaned. At this point having read other threads the MAF sensor is changed (more than £100), however after live monitored of the MAF sensor my mechanic didn't think this was the problem. Instead other threads were suggesting a fault with the exhaust pressure sensor. We came up with the theory that the pressure sensor was reading low, so the EGR was going wide open to get enough inert gas. With the EGR now clean, exhaust gas was able to flood in causing the shudder and displacing the air flow. The exhaust pressure sensor is at the end of a 30cm pipe bolted on to the exhaust manifold with a 14mm banjo bolt. Groaning from the mechanic because access behind the engine is difficult but after a while off came the pipe and sensor. At this point Volvo would want £100s for a replacement pipe and sensor. However my mechanic thought it worth checking the pipe for blockages. The sensor can be removed from the pipe with a deep 27mm socket. This leaves a pipe with both ends open, indeed it was blocked solid, nothing could be blown through. As the pipe was stripped to only metal then very aggressive de-blocking techniques were used and after a lot of huffing and puffing the pipe was unblocked. More groaning at reassembly but that's it, the car is fixed.
So thanks to this forum for hints and to the nice mechanics who are kind enough to help rather than just milk you for money. Please message me for further info or clarification if required. I'm located in Peterborough.