S27 F08 Error Code - Confused

[RSR]

How high a rpm do you usually run at? Carbon build up in the exhaust tends to come from incomplete burn. Low rpm could be keeping the turbo from spinning up, resulting in too little air for the fuel being injected. How often was regen kicking in? Try running at higher rpms (2k+), even if you need to downshift to slow the speed. The emission crap will be happier.

After warming up, I always run it at 2,200+ RPM. Regen occurs at 50 hour intervals on the dot (when the software forces it into regen even if it doesn't need one).

I've done this since the day I brought it home, which is why it's not clear to me that the EGR valve is full of carbon. My only worry is maybe there is an electrical control issue that is the underlying cause. The trouble-shooting procedure for the error calls for checking the signal to the EGR valve to make sure it is opening/closing at the right time. My dealer didn't do that step.

 

[Avenger]

Thank you for the update. Hopefully when someone else has the same issue, they can search this forum and find a possible solution. It too common people find a solution and forget to update the threads.