Hi, I am a newbie here but I have had my 2001 Ram 2500 for over 20 years and have done the majority of my own maintenance and repairs on it. I have the cruise control not setting issue and I have checked the normal trouble spots and have not found any problems. I have no trouble codes shown. It is not the clock spring as the instrument panel shows the cruise control indication on and off with switch activation. All vacuum lines are fine. As I will have to pay for a scan, what real time data is available from the scan? Can the scan show cruise control switch activation and PCM output? Since Ram no longer has parts available for the cruise control system, I must find them in the recycle yards and thus I want to know what I have to find before I go foraging.

Any information on the scanning process for this problem is greatly appreciated!

Thanks much,

John

 

did you check for vacuum at the servo? i would likely look at the cruise control servo after that. could be a sticking diaphragm. pretty sure you should be able to test it by applying power to 3, then ground terminal 4 and 1. you should be able to do this with the truck off is the vacuum system is working as it should.

 

I have a period correct OTC Genisys scan tool and it can show the voltage from the button circuit and decode it into which button is pressed. Years ago somebody on here posted the respective resistance values in this thread: https://dodgeforum.com/forum/2nd-gen...related-2.html So you could just use an ohmmeter at the connector for the switches.

 

Thank you for the reply. Since the cruise control servo is a pita to get to on the diesel 2500, checking it in place is almost impossible to do. Getting to the powertrain control module isn't easy either. Reading the pcm inputs by scanner is the easier way to go.

Thanks again,

John

 

Keep in mind, one of the common failures on the cruise control is battery detritus dripping on to it, and eating the diaphragm.....

 

at least the servo's are plentiful at the auto recyclers. i think i used a cruise control servo out of a 2003 dodge caravan on my 93 when i installed cruise in it. servo plugged right into the harness which surprised me. i would always check the diaphragm. sometimes they are actually fine but just stuck to the inside of the housing from rust and lack of use. just a little push and they start working like they should again but you do practically have to remove them to push the diaphragm in.

 

What model OTC Genisys scan tool did you use?

Thanks,

JLC