Mid 130 psid 204 fmi 8

[Macktruck1]

I own a 2012 cxu613 mp8 mdrive  
vin 021248. Im having an issue that nobody can figure out. I changed my batteries in December and now I’m having transmission issues. I had to change the battery because one went bad and was steaming out the side vent. The inactive fault from the title is the only code I get. The truck will be running perfectly and then the throttle cuts out, boost cuts out, and speed slowly coasts with no power or acceleration. It’s like the truck goes in to limp mode. Sometimes it catches gear and keeps going, sometimes I have to get off the hwy and wait for it to shift back down to a lower gear. I’ve heard of things similar to this with Volvos involving the ribbon harness, but nothing ever with Mack. I’ve noticed that when I get going on the hwy if I put cruise control at 55 it never loses power and this issue doesn’t exist. Right now I don’t have any active codes and the bendix isn’t showing any bad abs sensors. Could it be Exciter ring miscommunication with abs module? 

[Mackpro]

Looks to be ABS related . Make sure the steer axle wheel speed sensors are  pushed in all the way . Jack up the steer axle . Unplug the sensors and hook  a good volt meter to the 2 wires on the sensor and set the volt meter to AC voltage. Spin the tire and the faster you spin the higher the voltage will get.  Should be able to get .25 volts. Make sure the wheel bearings are not loose.  Also does on only happen when it rains or wet conditions? 

[Onyx610]

Unplug it and check for shit on the face of the sensor as well. 
 

Edited January 8, 2023 by Onyx610

[Macktruck1]

@Mackpro  @Onyx610 I’m down here in Georgia and it started in early December when we had a run of rain for about a month. Rained every other day for the entire month. I also recently started taking my truck to places that have a lot of mud and gravel. I bought a new abs sensor for the front and toner ring. I’ll have someone check all that out. Thanks for the advice. I’ll let you know how it goes. God bless.