Mackpro

It was a weird set up compared to domestic trucks. The only downside is that the air compressor ran all the time. I guess it’s the European way of doing things. I still have lots of Midliner service manuals at work.

https://n0c357rmy1njbuit2friqwu.blob.core.windows.net/documents/3UaRo$KdI0EBhB_TCH-008-012_US_001.pdf Here is a bulletin on adding a Bendix air drier to to the Midliner air system. Also Robert Bosch built the air pressure regulator that controls the tank pressure. I think the larger and last Midliners used a traditional type air compressor and governor.

From what I remember from working on Midliners at the dealership in the late 80’s and into the 90’s was that the air compressor on most Midliners pumped all the time . They had a pop off valve down by the air tanks that would open at a set tank pressure and close when pressure dropped to a certain PSI. I remember it was a pain to install a air drier. I’ll see if I can find some info on it.

The VECU code PSID40 FMI 4 is for your daytime running light module missing from the fuse panel. Lots of drivers pull them out and throw them away for some reason.

On our trucks this sometimes happens when it rains or we wash the trucks. The rubbed bare wires in the frame rails seem to short out more easily when it rains or wet.

As Onxy said the ABS and ATC system can cause dead throttle pedal issues. I thought it was only on the M-drive trans trucks but also happens on outer manual trans trucks . It was throw a Speedo sensor code as well.

The connecting rods are “ Fractured Fit” on MP engines. They freeze and break them when they are whole. So they have a rough look where the lower and upper meet.

I believe there was a service bulletin on replacing the complete tandem pump assembly when there was leakage at the tandem pump weep hole. I replaced one on an older MP with 800,000+ miles on it . Where the fuel pump bolted to the powers steering pump was chewed up inside where they connected. It was one of the few times where I pulled the injectors on a hard starting complaint and it wasn’t a cups issue.

The 04 emission MP7 in the CTP/CXP has copper injector cups and there is no upgrade to the stainless cups and updated injectors for this engine. However there are upgrades to the injector hold down yoke and bolts. There service bulletins out there for the parts and procedures

When I would go the the Mack schools in Atlanta and Chicago they had the big posters on the walls of the quad turbo engine.

Using the stalk switch on the right side of the steering column. Go through the display screen till you see “Trip Info “. Enter into the Trip Info and you will see Trip1 and Trip2 and engine hours. Go into Engine Hours . If all you see is dashes then the Engine ECM is not powering up . Possibly bad engine ecm or low voltage/bad ground to the engine ecm .

The braded line that run from the expansion tank to the top of the top radiator pipe has been know you collapse inside . Take the line loose at the radiator hose and see if you can add more coolant. Sometimes the elbow fitting on the expansion tank is actually a check valve with a ball in it. This can get stuck and cause issues. There were many variations of expansion tanks and piping and fittings over the years and service bulletins for upgrades that could be done .

Usually we get over temp on the T2 temp sensor and the regen kicks out when the injector cups are leaking . However , going over some old notes , yes , the cups can cause all sorts of regen issues.

Drive it around the lot. Sometimes the ABS Ecm needs to see wheel speed to clear the code.

Is this on a newer truck with the power divider and inter wheel lock too?

I always found it weird that they hid the brake light switch on the outside on the RD’s with an ETECH engine. I can’t remember If the earlier RD’s were like that as well.

Being it’s a GR , all the lights go through the LCM . Light control module. In the fuse box on top of the dash check all the fuses marked LCM1 -2-3-4-5 . There possibility as many as 6. Also there is a fuse F49 that is related to the back up lights .

Look for a switch on the dash or on the overhead console that shows a fan blade and says sleeper or bunk. This shuts off the sleeper heat/ac

The S22 code is the Mack 3-2 code rpm sensor on the flywheel open circuit. The S231 is the J1939 data link between the Ecm’s. These are always green and yellow wires twisted together.

https://macktrucks.vg-emedia.com Type in SB221034 , this is all the terminal part numbers for the pins for the connectors on the ETECH and ASET engines. The connector bodies themselves are harder to look up. The dealership can call parts specs and they will send them the blueprints of the harness with the part numbers of the connector bodies. Just had to do this on Monday on a ASET.

The upper black rubber bumper part number is 12AX141

https://static.nhtsa.gov/odi/tsbs/2013/SB-10054150-5440.pdf

There is a metal “L” bracket that is on the steering column bracket. This “L” bracket serves as a upper stop to keep the clutch pedal from coming up to high. There also a rubber bumper on this “L” bracket. The rubber bumper usually falls off and the “L” slowly get bent up allowing the clutch pedal to go higher. This is Partially due to incorrect clutch adjustment and /or the clutch cable length adjustment or stretch. I’ve seen people bend the “L “ bracket up to get clutch free travel when their clutch wouldn’t adjust anymore. If you have the big “grated” clutch pedal,, it was a option. You can get the standard pedal still I believe. It was easy to change,

https://www.mid-americaclutch.com/literature/mack-truck-sb313005-air-operated-clutch-assist-adjustment-troubleshooting/

Great point , most all of the individual connector ends are still available for the ASET engines. Just last night I replaced the harness end on a 2005 CHN ASET turbo actuator . Anymore the harness can be repaired unless damaged by fire which was common on the ASET AC engine