Mackpro

There is a bulletin on putting the EUP back together if you have one that has popped apart. I’ll attach it here. Also they do make oversized EUP roller guide pins if you ever get into a situation where you need to replace one and the original size pin is not tight . https://www.scribd.com/document/372397084/MAck-Bomba-Unitaria

Your truck was built 1/19/05. AI427 engine , T310M transmission, has the 92/93 series carriers with 4.64 gears, the 4.64 gears are a must with with a AI engine and any tire taller than a 22.5 full-size. Your fan clutch is a Horton Drive master air fan. Your engine ECM was replaced back in May of 2011 and is up to date software wise. Your VECU vechicle ECM is at software level Step12 and would be great if it was reflashed to Step12B , helps with throttle response. The 460 XT program was only for early ETECH engines 1998.5 to 2001.5. Yours could possibly be bumped to 460HP with a software update. However the turbo would have to be changed to the bigger one. If you have a good local dealership that can submit a HP request.

That ECM number is just a part number. Has nothing to do with what engine data file/Hp level it is. Need to get that fan issue figured out as it draws up to 50 HP when on. What’s the last 6 of the Vin ?

Updated cover with gussets

No gussets

I believe your onto something there. Vibrations did cause 3-4 codes and Mack came out with a new front timing cover with casted in gussets around the cam timing sensor. I believe many many years ago I had a Eaton ultra shift truck and the centrifugal clutch was out of balance and caused a possible 3-4 code . I remember I replaced the clutch and it solved the problem.

It seems they never made a troubleshooting guide for that style fan clutch on the AI engines. The electric viscous fan clutches for the AI and AC engines look identical and will actually bolt up but they have different part numbers. The troubleshooting should be the same only difference would be engine ecm pin location.

Your correct , I forgot that the GR , Athem and Pinnacle all use the LCM light control module now. There are about 6 fuses for the LCM . We have never found out what fuse does what. I’m thinking it’s a parameter in the LCM that can be turned off with Tech Tool.

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.