I have an 01 Dakota 4.7 4wd sport club cab. The cruise will shut down if the truck has to downshift out of o/d. If it comes to a hill and it downshifts, the cruise just shuts off. I can run the cruise fine until it has to downshift. I’ve changed the sensor on the rear end, tps and there are no vacuum leaks. There is an airbag light on, but I can’t imagine that would cause the issue. Anyone have any suggestions where else to look? Just got it back from the dealer and they are stumped also.

 

Does cruise disengage? Or does it actually turn off the light?

 

The light stays on, it just disengages. The truck should be able to downshift out of o/d to maintain speed without disengaging the cruise correct? Or is this working as intended?

 

No, it should stay on cruise. What gear it is in shouldn't matter. Something else is going on. Likely need to do some data logging to see what's happening.

 

I have a handheld scanner from Oriellys. I don’t know if it will show what I need to see. Transmission module maybe? Other than the cruise, the truck is great. Only 62k on the meter. Trying to get it perfect so my daughter has a truck for high school.

 

Might be something with the brake light switch, or loss of speed sensor input, or a WRONG speed sensor input..... (cruise won't engage above 80mph, I do believe) Gonna be some experimentation involved there.