Diesel Engine Emission Codes

This is yet another post on diesel engine emission codes which will never go away until all vehicles are hybrid electric drive. I think the fossil fuel manufacturers are very happy to supply billions of dollars worth of fuel to the world as long as they possibly can. For now all of the responsible people of the world will be banging their heads against the wall trying to prevent diesel engine emission codes.

Preventing the codes from happening requires a lot of driving and regens that the on board computer controls to keep the exhaust system clean and code free. Of course in a perfect world this would be an ideal situation. We have fifteen 2007 and 2008 buses with diesel engines that constantly code and require maintenance to keep them on the road. The Mercedes MBE 900 before 2007 was a finely engineered diesel engine.

The engineers were given the task to change the design to allow all of the crankcase emissions to be consumed by the intake side of the engine instead of the old ways of pumping all of the by products of combustion into the atmosphere. This was a great idea to clean up the air but down the road these internally transferred emissions ended up being a sticky mess that clogged up everything involved with the emission system.

The EGR valve and cooler along with the DPF filter could not handle the wall of soot that came on down the line. The passive regen controlled by the engine computer to keep up with changing this soot to ash for removal wasn’t enough. The engine code would come on the dash to alert the driver that there is blockage in the exhaust system and we aren’t going to give you any horsepower until this problem gets fixed.

Oh yes the software was written to make sure all power was lost until that engine code was fixed. It worked because a school bus travelling at a maximum speed of 60 KPH down the highway was not compatible with the regular flow of traffic. So along came the technicians to remove parts for cleaning or replacing because of the sludge buildup that hindered sensors sending the correct signal or a mechanical device opening and closing when it was supposed to.

The diesel mechanic in today’s world has to be computer literate and ready to troubleshoot emission engine codes as they happen unless you want your bus or truck to limp down the highway looking for the sick bay. It does get easier as time goes on….. with a little experience and time anything can be fixed.