Mackpro

Also, don’t throw it away. Keep it in case you want enable it again. I believe that little module/relay cost about $300

In the top fuse box. Towards the left by the flasher. See the DRL in pic , bottom left

Here’s the bulletin for the same fan clutch but on the Aset AC engine that’s in the CX and CH style trucks. Your AI engine has 2 connectors on the engine Ecm while the AC engine has 3 connectors on the engine Ecm. Troubleshooting should be code to the same . I’ll try to find the one for the AI engines https://pdf4pro.com/cdn/service-bulletin-mckenzie-tank-lines-a3dd0.pdf

As TJC said , the turbo cool down feature is turned on in the parameters. You should be able to turn the key back on then back off and the engine should immediately shut off. And also possibly the idle shu down is turned on as well.

Here is one that I had already removed the orange flapper and it was plugged solid. One time I did have the screw that holds the flapper on break off in the filter housing so be careful. Might be possible to clean it out without removing the flapper

https://static.nhtsa.gov/odi/tsbs/2021/MC-10195317-0001.pdf this is a must on the common rail engines. Software update is required so it’s pretty much a dealership repair.

Mack deleted the fuel supply pressure on the common rail engines starting in 2017. They added it back on in middle 2021. Has the EPRV delete been done by the dealership? Biggest problem we see is trash gets stuck in the orange flapper in the rear of the fuel filter stand. Pull off rear fuel filter and remove flapper and check for trash. I’ll add pics soon

Joey is correct, sounds like a J1939 high speed data link issue. The truck is running on the low speed data link J1587 so that’s why there is a delay between key off and actual engine shutdown. The J1939 wires are always twisted green and yellow wires. Sometimes it will have a third wire which is a shielding wire. The used VECU should work even though it’s the wrong VIN. But will have to reset parameters such as , road speed limit, tire size , rear gear ratio and trans top gear ratio. The HP level is only in the engine ECM. I wish I had seen this post way earlier. All R-series trucks with ETECH engines had their VECU’s mounted with the connectors facing up. And a Joey said the windshields leak right into them. The first sign of any weird issues, this is the first place to check ( on a R-series). It would have been nice to get the VECU programed to match your truck . But if the Tech was not 100% confident then it’s probably best he didn’t. Programing VMAC 3 ECM’s is a multi step process and one wrong move and you turn the ECM into a paper weight.

I have no experience or heard of anyone that actually used what you described. But back in 2002 or so I custom flow ported a ETECH exhaust manifold, exhaust ports of the heads and exhaust inlet of the turbo. I spent about 8 hours with a die grinder , best I remember it only gained maybe 2 psi of boost at most , this was with a truck with high flow dual exhaust. But now days with EGR and DPF ( very restrictive exhaust) I’m not sure how much it would help.

That’s weird that your GU with an Allison had the 505 HP program in it . Biggest we could get with an Allison in the GU was 455M like you got now. If you had a Mack manual or M-drive or the higher torque rated Eaton you could get the 505. Engineering told us the radiator in the GU wouldn’t keep the Allison and 505 cool enough. What’s the model number of the Fuller you used? Glad your making progress.

On the MP8’s. The VECU (vechicle electronic control unit) and the EMS (engine ECM ) both have to agree to start/crank the starter. When you turn the key to start/crank , 12 volts goes to the VECU A connector pin 6. If everything looks good to the VECU it sends 12v out of the VECU connector B pin 28 which goes to the little start relay in the fuse panel by the clutch pedal. This in turns sends 12 volts to the small silver starter solenoid. However the ground wire on this small solenoid goes to the EMS engine ECM bottom connector pin 29. The EMS has final say by internally grounding the solenoid ground wire allowing the solenoid to crank the engine. So everything has to be perfect in the eyes of the VECU and EMS. Make sure the green PTO light is not on . It will not crank if the VECU thinks the PTO is engaged.

The biggest issue I see is why it won’t crank with the key.

There are 2 different part numbers for manual trans harness . 21902988 or a 21902987. The possibility the first is for Mack and the second for Eatons . As some newer Eatons have different reverse light switches and speedometer connectors that the Mack and older eatons . Still looking for more info

Also make sure the start relay is installed correctly. If turned 90 degrees it won’t start. People pull theM out to check them and put them in wrong. More info to come

Also is this a MP7 or MP8?

Looking to get you a part number here shortly

There is a 12 wire connector/harness that plugs into the chassis harness under cab . This is the manual transmission harness. It’s for the speedo sensor, reverse light switch , transmission temp sensor and PTO.

First make sure 20 amp fuse/breaker is installed at fuse 42 in fuse box by clutch pedal. More info to come

As far as Corporate helping dealers with issues like this ( change overs as they call them) it’s non-existing. They will set up the data files and if you lucky they will give the dealerships a Vin of a very similar truck as yours but with a manual transmission. Then it’s up to the dealership to go through each page of the parts look up and compare what’s different, from fuses, breakers , relays and harnesses. Been through similar situations with them years ago. They don’t make a parts list or how-to on things like this.

It’s a separate harness that plugs into the chassis harness on top of driver side frame rail. I’ll see if I can get some pics in the morning. I’m thinking the Allison harness is separate and goes directly through the firewall with it’s own harness.

The 1400 rpm is the default max RPM when there is a “Speed Error” . I always set this to 2150 in the Parameters when setting up a truck. Mack never really explained which speed error. I always assumed it was crank or cam sensor. When the flywheel was changed it’s possible the crank sensor could have been damaged as it reads off the notches on the flywheel. The truck should still start. There is a different wiring harness for manual transmission trucks . Don’t use the Allison harness

I just worked on a 2006 Volvo VNL with the pre-emission D-16 engine. I didn’t think to look at the HP rating. It seemed to run pretty strong though. Volvo pushed the VNL as their heavy haul truck with many different engine options for many years. After the Mack Titian and MP-10 was discontinued in the US , Volvo pushed the VNL again as a heavy haul truck with the D-13 500HP/1900 ft pound torque or the Cummins X15 565HP/1850 ft pounds of torque. The Mack MP8 is maxed out at 505 HP/1860 foot pound of torque. It seems the Mack 505 Plus ( 1900 foot pounds of torque) is no longer available. The 505 Plus was a beast but seemed to cause some weird vibrations when under long hard pulls in the CHU trucks I worked on . I believe the 505 plus was available between 2014-2016 and pre-common rail engines in 2017 .

On your oil level/temp sensor. It’s the same one that’s used in all MP engines. Original part number is 21042447. That part/number has been updated 5 times over the years since 2008. The new number is 23285701. And apparently there is a national back order on them .

I even found my harness I made up to test it. What I have found is the rubber insulation grommets that the ecm bolts go through seem to shrink over time and this causes the ecm to vibrate/shake and causes the ecm to fail.