After a financially painful failure of my C9's HEUI pump and subsequent replacement of all 6 fuel injectors, I would like to monitor any points available but find none in the list of PID's on my VMSpec (2.5). Is there some way to identify points and add them to my monitor?

Submitted by Art on Thu, 2017-06-22 08:31


What year is that engine, 2005/6? Hello Dave, If no sensors are showing up in the sniffer we then don't (typically) have any to monitor. On an older engine this is especially so. You should have, as a minimum however, fuel rail pressure. On many Cats this is used to judge oil pressure (as fuel rail is oil pump driven and there's no oil pressure sensor.) I believe only Cummins has a sensor on the lift pump. Even that is more of a switch; (Shorted/ Open/ Okay) Maybe some of the Other Cat owners could weigh in here. cheers Art //

I believe I identified PID164 "INJECTION CONTROL PRESSURE" for my C9 in the VMSpc diagnostic events. However, the sniffer does not find this or anything related to fuel or the HEUI pressure. My software version is 2.5 Build 4. Do I need to update? Can this PID be added manually somehow?

Submitted by Art on Wed, 2017-08-23 09:25


Hello Dave We can monitor any process for which CAT put a sensor on. If you don't see a particular PID for thing you want to monitor, it indicates that there's no sensor for it. Adding a PID is really then adding hardware, pinning it into your ECU and having the ECU reprogrammed to reflect the new sensor. I know of gear heads who've added EGR sensors in this way. Very expensive and...maybe more of a pride-in-accomplishment chase than a practical one. No PC software updates can change this dynamic; sorry. Art //

Submitted by RVAcer on Mon, 2017-11-06 01:24


Not only do I use VMSpc, I also have Cat software and the hardware to program the engine computer. Also on my coach the Wabco anti locking brakes, and Allison software. Cat 3126 330 HP In the cat software I can watch the injection pressure, so the engine computer has this information. Take your engine to a cat service center and check for injection pressure. It might be interesting to watch but not to useful. It actually bounces over a wide range. There is a pressure sensor above the injection system and a pressure regulator screwed into the pump head. The Cat engine computer would store failure codes for bad or fluctuating pressure But VMSpc would miss them. Given that this engine produces unreal injection pressure I changed the pressure sensor first. Bad choice it was a bad regulator valve. Good news you can now get as a rebuilt valve. I stopped by a Freightliner dealer and they were only going to stock the rebuilt. I got the last brand new valve for the rebuilt price. Even without the software the engine will derate if injection pressure goes out of range. This may be your first notice. As a afterthought always use a 2 micron fuel filter, do not pour it full of diesel before putting it on, and clean the filter and housing before removing the old filter. HEUI systems are rather picky about dirt in any form.