96bulldogpower

Hey guys looking for help again on this one. Dealing with a 2012 granite with the mp7. The problem started when the dash requested a regen “SOON”. I tried to regen the truck with the dash switch and it would only raise the idle and drop after 3 seconds. I hooked it up to PTT and discovered spn3675 fmi7 for a fault on the turbo bypass valve. I diagnosed a faulty valve, replaced it and verified its function then it allowed me to properly start a regen. When it first started a regen the truck blew HEAVY gray smoke for a while, the regen lasted just over an hour when it was interrupted by the low fuel light. I quit that day and tried again today, filled the truck with fuel and tried another regen. Now the dash says regen “REQUIRED” I allowed it to regen and it lasted over 2.5 hours with no signs of stopping, I stopped the regen because I had to be out of the yard by a certain time. No codes are present, egt’s while regening are around 750° at their highest, differential pressure has now dropped to about .03-.06 but it still blows a little gray smoke while it’s in regen, on jpro it says soot level is at 48% and I can’t get it to drop, also truck is in low derate. I’m not sure how to proceed, anyone have any tips on what to do or check? I’ll attach a pic of my jpro screen.

I’d sure appreciate any info or schematics! I haven’t had time to dig further into it, but any info would help a lot! I am also suspecting power/ground problems but have no real way of getting diagrams for this truck. I did find some corrosion at the plugs on the epdm by the driver side kick panel/firewall inside the cab, I cleaned the plugs but it made no difference.

Did you ever find the problem? just my experience with an 05’ CHN AC engine/allison auto… we had this truck that would overheat and push coolant out of anywhere it could, most times it would be from the reservoir cap until it got worse and started blowing out the plastic radiator end caps. We replaced two radiators before we got to really looking at the truck. We found that the egr cooler had cracked and caused exhaust gas to pressurize the cooling system. We replaced the egr cooler and further investigated the cause of overheating which cracked the cooler. We found that the big aluminum coolant plate where the water pump goes mounted to was eroded badly at the water pump impeller area. We ended up replacing the whole coolant plate and new water pump. Since the water pump couldn’t efficiently pump coolant because the plate was eroded, it caused a low coolant flow condition, it gradually worsened until the engine started overheating and cracked the egr cooler which then pressurized the cooling system and caused it to overflow. It’d be worth looking into if you haven’t already fixed it, we had no oil/water contamination. Sounds similar to your situation. If you remove the water pump look into the coolant plate and see the area where the water pump impeller sits, inspect for ridges or eroded material.

If you can get past the cam issues on these AC’s, they’re GREAT engines. This one in particular got larger injectors and home made egr delete. Since I can’t get tune files anymore from my dealer, I got a used 460p ecu and it was a major upgrade from the 380hp file it had. I never got it dyno’d but it makes impressive power!

It’s a love/hate relationship for me, when the mp’s work they work great! Until it’s time for repairs 😂 I have always loved the colors too, hence the color scheme on this one after rebuild

Hi, I did this to our 07’ CHN during a total overhaul. We made a plate to remove and cover the opening for the valve using 1/4” plate steel, cut out a template on cardboard and traced it onto the steel, used new gaskets and bolts. For the oil lines I went to my hydraulic shop and got some plugs/caps to remove the lines completely from the source. We made caps for the two coolant lines and the egr intake port. Disconnect and remove all egr associated wiring. We removed the entire egr valve, crossover tube, egr cooler, and all the lines. The result was a much cleaner engine bay, the truck runs perfect and I’m satisfied knowing it won’t introduce exhaust gas back into the engine. The only side effect will be the engine light permanently on. Other than that, the truck has been running great for almost two years since we did it.

Hello guys! I have an interesting one, wanting to see if I can get some help with. I have a late 07’ Granite with the MP7 pre-dpf engine. It has an Allison auto. The problem here is that the truck was idling one day and it shut down suddenly, we replaced the fuel filters and it changed nothing, it’ll crank but won’t start. On Jpro I’m getting PSID200 FMI9 for datalink mid128- abnormal update rate…. There’s also another code but I don’t know if that’s related, it appears it’s for abs and this code is SID231 FMI 14. Occasionally there is also psid204 FMI9 for datalink mid136 abnormal update, but this one doesn’t show up every time. I’ve chased all of the connections in search of loose wiring or plugs, checked all fuses and swapped relays, checked plugs at pcm. It’ll run on ether, while it’s running on ether there is no rpm or oil pressure on the dashboard. Any help would be appreciated! Thanks y’all

Hi Shortdawg67. I removed the entire egr system from my 2007 CHN ASET AC engine about a year ago. The truck runs better than ever, keeps the engine oil cleaner longer, and I don’t have to worry about all the extra EGR junk. I started by removing the cooler, valve, and crossover tube. Leave ALL associated electrical connectors disconnected and zip tied out of the way (you won’t need them anymore), create a 1/4” plate to cover the port where the egr valve was (I used a piece of cardboard to make a template and then cut the plate to shape). You’ll also need to cap off the two coolant lines leading to the egr cooler, cap off the egr valve oil supply line and the oil return port located at the turbo drain pipe. Lastly, you’ll have to cap off the EGR inlet port that’s located at the intake horn on the intake manifold. You’ll end up with a lighting bolt on the dashboard indicating errors for egr, but in my case the truck does not de-rate or have any other issues. All in all, I’m very happy with deleting the egr off my truck, it does away with potential coolant leaks, allows the engine to run cleaner and cooler, less items to break down, and the engine is easier to service without all that junk in the way.

Masterwelder, thank you so much for the reply, such great info and detail! I found a prolink plus but the cartridge is VMAC III “Version 6.00, System Software 3.09” which sounds slightly older than yours. Will this still work? If so, I’ll order now. also, is having the donor VECU mandatory? I got the etech EECU from a private sale and they do not have the VECU. I’m currently running the original VECU that the truck came with. Prior to changing the EECU to the etech, the fan and engine brake worked as designed. I’m pretty sure the parameters for both of these functions lie in the EECU, but I’d like to double check with someone more knowledgeable than myself. side note, I had a EECU from a 300 etech and both the engine brake and fan work properly on the AI, so I’m hopeful this is simply a matter of programming the right settings.

Hey guys, I’m hoping to get some help with a rabbit hole I’ve gone down with a 2007 Mack CV713 AI 400. This is a triaxle dump truck we just put together, when put into service we discovered it is absolutely gutless, it was pretty much unusable for what we do. Long story short, we’ve been throwing parts at it in an effort to make some power with it. The problem is that our local dealer is useless and won’t uprate the horsepower. So we bought a ECM from a 2000 CH 427hp engine, we knew we wouldn’t make power with any of the available ASET AI data files anyway so we’ve decided to take it back to an etech ecm. The truck has gained a bit of power and is now usable. Unfortunately the donor truck we pulled this ecm from did not have engine brake and apparently didn’t have an air fan clutch because the fan will not turn off anymore. My question is, will a tech tool with V-Mac III software be able to turn on the air fan clutch and engine brake functionality in the parameters? Or is there such a thing? If so, I’ll be purchasing a tech tool very soon. list of mods to truck: etech exhaust manifold, s475 74.5mm turbo, 460HP ASET injector nozzles, ECM from 427 etech, 3.65 rear gears as a side note, the truck runs considerably better, has more power throughout the power band. But it still feels sluggish, we have a similar spec’d ASET AC truck with 355/380 ECM with K&S injectors and the same gear ratio and it pulls HARD compared to this troublesome truck. Is there any other modifications I can do to this AI to make it have more power?

Hey guys I was wondering if one of you Mack gurus with access to part number information could help me out. I’m needing to replace the camshaft in my Mack with the aset ac motor. I have a GC5247 cam in it now, but I have access to a reconditioned cam with part number GC4268. Can anyone tell me the differences between them? Will the reconditioned cam be a drop in install and work with my engine? Please help!

Turckster, very helpful! I did what you said about checking the timing. The timing is right where it needs to be. I have done a few things since I last reported. I bought and installed a used ECU and VECU, thinking that it would solve my issues but it did nothing, as a matter of fact the engine wouldn’t even crank with the replacement computers, I did not even get anything on the dash screen just like before. So I reinstalled the factory ECU AND VECU, and I’ve decided to stop chasing electrical issues because all computers are getting power and the truck seems to respond to the gauges most other functions just fine with the exception of the dash screen. The truck still refuses to start on ether. I’ve checked the fuel system and it is getting fuel just fine. I even went as far as replacing the filters and a new fuel lift pump. Still no start. The engine may sputter a few times while it is cranking on ether however it never actually starts or fully runs on ether. Any ideas of where to check next? Also, I do not have a diagnostic tool or a way to check compression.

I primarily buy trucks at auction for our family business. I know what you mean about auction truck nightmares, but I bought this truck as a known non-runner. So I guess you can say I dug my own grave. I’ve chased all the typical electrical connections and all seem good. I’d like to know which pins at the ecm to test for power, do you happen to know which they are? Although i haven’t tested compression, the engine doesn’t sound like it is freewheeling or has a dead cylinder as it cranks over. Obviously not a accurate way of gauging compression, but it does sound like it should. I’m concerned that it won’t even run on ether, leads me to believe there may be something wrong with the timing, what gets me is that it does “stutter” once or twice as it cranks over as if it was trying to start. The other concern is that the dashboard info screen doesn’t come on, leads me to think it may also be ecm related. Everything else checks out good, no shavings or out of the ordinary in the engine oil, everything looks mechanically sound, all fluids are topped off, new cam and crank sensor. I’ll do some more checking once the rain lets off, just wanted to get you guys’ opinion

Hey guys, I’m stuck on another truck again. I’m working on a 2014 Mack CXU with a MP8 and mDrive transmission. Bought the truck at auction, so I know nothing about it. Put fresh batteries in it and a new starter. I have looked through the fuses and found none burned. The truck cranks and every now and then sputters like it tries to start but never starts, not even on ether. While cranking engine, the engine sounds fine, no abnormal mechanical sounds present. Another thing is, the information screen on the dash does not turn on. Have any of you guys encountered this? No codes, and as far as I can tell the fuel system is not building pressure, but i may be wrong about that.