LML Duramax DPF Regeneration

The Duramax regen system operates seamless/stealthy by design. In typical operation you will not notice that it is happening. The indicators are very subtle. Idle speed will increase from the 720 standard to approximately 850. You may notice a hot smell when standing. The instant economy calculator will drop to about 13 mpg more or less. Seamless is nice, but the issue is that it is not quite smart enough in many cases to identify the fact that it is not burning hot enough or completely. Fuel for the regen process is delivered by an extra injector in the exhaust pipe. This fuel combusts and builds the extreme heat needed to burn out the soot. This injector has had enough issues on the earlier models that GM issues a special policy warranty extension to cover it. Not all will fail, but if it does the owner often does not know about it until the DPF soot load gets to be VERY high. Sometimes it's too late to correct without creative measures.

For this reason I highly recommend the Edge Insight CTS monitor. Having a monitor like this allows the end user to watch what is going on and helps with diagnosis. You can track miles since last regen, soot production, regen status, and even command a regen cycle to occur when convenient for you. It can also read and clear diagnostic trouble codes plus a whole host of other features.

You can find this monitor here: Edge Insight CTS