Mackpro

FMI 3 or 5 could be the harness end as Steeler said . FMI 7 with miss or running rough could be oil control valve stuck open or stuck engine brake plunger on rocker arm

+1 on what Steeler said. Also , there is another bulletin on injectior fault code due to the engine brake malfunctioning. I believe it’s only on the MP7 that this would happen on. The FMI is key in determining what to do next

There was a Allison Guru on either a school bus fourm or a motor home forum that had lots of good tech info on the Allison’s .

We have zero issues with the Horton 2 speed air fan clutches on the AI CV’s like yours. Wonder what brand they are selling you?

Valve spring failure and bull gear failures can be a death sentence to these truck when getting over the 750,000 mile mark. We had 3 parked out back of my old work that were just to costly to repair. You do a in-frame on a million mile engine for $15,000 then only to have the bull gear go out or valve spring break later down the road. These engines are very labor intensive and the only way I would proceed would be a complete reman Mack engine. Every thing new/rebuilt and under warranty. Then you gotta ask, is this $25,000-30,000 truck worth a $30,000 engine? Roll the dice and truck on till a major failure then part it out or off to the scrap metal business, that's the way it seems to work around here sadly.

Had the same thing happen to me on an old CH . I had to turn the crankshaft just right for it to clear.

Message set to ya about fault code/service bulletin

If the previous work was done in your shop and you know which laptop was used, you can go to “latest selections” and chose the truck from the list and connect ( you actually don’t have to be hooked to the truck to do this). Then go to “product history “ at the top. You can go back and view the fault codes from the other times that laptop was hooked to that truck.

Also , what was the actual fault code number. I saved all my tech bulletins and might have one dealing with the code

Somewhere around 2013/2014 they change “learned data reset” to “function parameters reset” it’s under the “calibrate” tab in PTT. Sometimes software updates help with weird fault codes. We have PTT where I work now but it’s the lowest level customer version. Trying to talk the boss man into upgrading to the customer version with software programing .

When I went to the Mack MP engine class in Atlanta they showed us why they use angle torque method. First they showed us why “not” to use the new modern angle tourque wrenches. They had a new Snap on angle torque wrench and fooled it many times by turning the wrench slowly. Then they showed us why angle torque is more accurate. During torquing say a head bolt to 150 ft pounds . That if you stop while turning the bolt ( stopping at say 130 ft pounds) due to the wrench hitting the fire wall then back the wrench back up to start pulling on it. To get the bolt started turning again while it at 130 ft pounds will probably require more than 150 ft pounds of tourque . So the Tech hears the click and thinks thes at 150 when really he’s at 130-135. Kinda hard to explain but they showed us right there in the shop and I saw what they were talking about.

Lots of corrosion issues in that fuse box by the clutch pedal. Bottom of the driers side windshield leaks and drips into the fuse box. There was a large recall that was done due to this issue.

The expansion tank and radiator are considered chassis items so 1 year/100,000 miles from in service date. You can buy extended chassis warranty. The fleet I work for now has extended chassis warranty on all the Mack’s. Covers about everything but tires, bulbs, belts, brake shoes and clutches. You will usually go through 2 turn signal switches , a radiator and 2 expansion tanks, a chassis wiring harness and various ABS sensors under the extended chassis warranty.

It’s not in my SPN code list for Mack. Usually the “SPN” codes are for 2010 Mack’s . On the 2005’s they were usually MID and SID fault code. If active you can flash out the 2 digit Mack fault code with the cruse control switches

On tech tool, click on “Test”. Then select engine. Then intake and exhaust. Then I believe, above or below the line for “Regen” you will see Exhaust Aftertreatment Diagnostics. , click on that line and on that screen towards the bottom you will seen the soot ratio reset button.

Did you zero out the door ratio after having the filter cleaned? If not , the ecm still thinks the filter (even though it regent fine) is ash packed or nearing capacity. Do learned data reset and zero out soot ratio and do a regen and do a 20 mile test drive and see how much the soot ratio rises.

If the blower motor only works on high the your correct that it’s usually the resister. Pull off the lower kick panel in front of the passenger seat (4 -T27 screws). You can’t miss the resistor. Large connector and 2 small screws holding it in. We also see lots of burned up wires on the back of the control panel that cause issues. This is a very good time to replace the cabin air filter while the cover is off. Mack has a new style filter out now that like house HVAC filter.

I believe the first couple of years the CX Vision was introduced you couldn’t even get Mack rears in them. But I do know that where I worked, we took lots of used CX Vision trade ins and pulled the sleepers off and beefed up the front springs, and slid Camelbacks under the rear end and put dump beds on them . I think we even had a local steel company bend us some frame rails so we could double frame them. I’d say we did at least 10 of them. We had a large local trucking company that would trade in 10-15 CX’s at a time and we had to do something with them.

Also anything ending in a “P” (CXP/CTP) will have a non-DPF MP-7. Usually only seen as a 2007 model. The P supposedly stood for Pinnacle.

The “ N” for sure means it has a ASET AC engine in it, that’s all I got. However the 2004 CX had the same engine as well. I can’t remember seeing a 2004 CH with a ASET AC in it though. When I did the warranty paperwork at the dealership, in a usual bad model year we would have about 325-350 warranty claims. In 2004 we had right at 670 claims. But in our area we still have several 2004 CX’s going strong.

What tire size on the rear and what rear end ratio you running ? Hopefully 4.42 or 4.74 in rears if running full size 24.5

Our policy was never reuse a line and alway do a 15 mile test drive after replacing any fuel line and check for leaks at head.

The best fuel lines were the ones on the original ETECH engines , they had the jam nut on the end that went into the head. They never leaked and could be used on the ASET engines as well.

The fuel supply line runs up the driver side of engine but the fuel injector lines are on the passenger side and there are 6 of them. They screw onto the high pressure EUP pumps and then go over the exhaust manifold into the the side of the cylinder heads. They are know to leak and catch fire if reused on the AC engine. The same fuel line is used on the AI engine but they never seem to catch fire like the AC engine

Fuel injectior lines every time. I've personally seen at least 6 engine fires on the 2004-2006 CH/CHN and CX/CXN trucks with the ASET AC engine. The injectior lines are a one time use item. Mack even has a video on them on installing them and all the techs had to watch it