Ok, this issue has me thinking about getting rid of this truck.

Seriously.

'08 Dakota, I've had it a couple years, 120k miles, 4.7 V8. Have had a string of expensive repairs happen since.

Cruise control has started to become intermittent, now getting really bad. I am an AVID CC user, and travel between our home and a vacation home weekly. KILLS me to drive on the highway for an hour and have to control speed with my right foot.

So started out that the CC just would not come on sometimes. That is, pressing the CC on/off button the wheel, the "CRUISE" light on the dash would not come on. Usually if I got it to come on, it would stay on. Then is started coming on sometimes, but then turn off on its own, even when I didn't have it engaged/set speed/controlling throttle. Until yesterday, it is dropping out even when/if I do get it to work. Driving me batty. I see YT videos on replacing the switch, but it seems odd that it could be the switch if it is dropping out even when I don't touch the switch (??). Seems like, often it will work when get in and drive the truck cold, but then next ignition on/off, it won't come on.

I am a retired electrical engineer, wires don't scare me. The $50 switch replacement video doesn't either, but could that be it?

Any advice/leads greatly appreciated. Other connections/fuses to check? If this a common problem?

TIA

JH

 

Could be the cruise control buttons or the clock spring. Since you sound like you would be comforgable with a screwdriver and wrenches both should be pretty simple. i know there is a clockspring replacement tutorial somewhere on here. i just can never find things on the search for whatever reason.

 

Did you ever figure out what was causing your intermittent cruise issues. I have a 96 Ram that the cruise will go on, works fine then for dome reason goes off and will not turn back on. Once I stop the truck and turn the motor off and on it works fine again. It will often run hundreds of miles before cutting out, other times it runs only a 100 and quits. I have checked the vacuum lines, which are the problem 95% of the time when you are having problems with Dodge cruise controls and that isn't the issue. Thanks

 

I had (still have) the exact same issue with CC on my 2004 ram 1500, 545RFE transmission 5.7 hemi. Sometimes CC works. Sometimes it turns itself off in middle of a drive. etc.

What I got down to is the problem being the shift position range sensor plate and pins on the solenoid pack in the transmission. Basically, the pins between N and D do not always "make" properly so the PCM thinks the the transmission is in neutral. The CC will not turn on nor engage when transmission is in neutral. Prove it - Try it.

The way I discovered this is tough to describe but I will give it a go.
It is an old truck with a nice half burnt out rumbler of a MagnaFlow muffler on it, AND I have teenage boy drivers who use it. To prevent them from popping connecting rods through the block when no-load revving the engine for the chicks; I used my tuner to program engine RPM limits in the PCM. I set the park/neutral rev limit to 4000 rpm. I set the on road in gear full throttle rev limit to 5500.

Here is how I linked the CC problem to the transmission. I was out for a long trip with the wife. CC was working intermittently along the trip. At one point I pulled out to pass another vehicle. Floored it. The hemi rip roared up to 4000 and capped there. WTF, I thought. About 10 miles down I found a turn out and stopped to check things over and collect my thoughts. I did not turn off the truck for fear it would not start again and where were pretty much in the middle of BushNawhere. Just stopped and put in park while I thought over the passing event. It had been over a year since progamming the rpm limits so it took some time for me to come around to it. Having figured the problem I put it in drive and floored it out of the turn out. The Hemi growled, barked the tires and rip-roared right to 5500. (The CC was again working fine). Aaahaaaaaa! I see said the blind man to the deaf man on other side of the brick wall. ... When I pulled to pass, rpm capped at 4000, which is what I had programmed for Neutral rpm limit! That is when the light bulb went on. At the time of the pass the PCM was being told the transmission was in neutral, so there must be a problem with the shifter range sensor.

It follows then that this intermittent range sensor problem is also the cause of the CC not working. At least seems to be the case on my truck. Now whenever the CC is acting up; I stop the truck. shift between N and D a couple times and take off, almost always the CC is working again. So, maybe try that. If your CC is acting up just stop the truck. Shift the stick back and forth D-N-D a couple times to see if the CC starts working. If it does ... then you have this same problem with the range sensor on the solenoid pack. If CC does not start working, then maybe it is something else or you do have the same problem except that the shift position range sensor is completely failed.

In my post event refection and research for planning a fix I discovered that there are different versions and updates to the 45RFE - 545RFE shift solenoid pack. The versions are identified by different electrical connector terminal colours. Black, white, grey. I believe this shift position sensor problem was corrected in the black to white version update as the white also includes a new and different shift range plate. The update literature is also very specific about the new plate being mandatory when changing/updating the solenoid pack from black to white. Fyi, the connector on my truck right now is black.

I eventually plan to take the solenoid pack out and take apart the shift position sensor plate and pins to figure out the what/why/how and fix it. I have no intention of buying a new solenoid pack. I plan to just inspect and figure it out. That will not be until the next transmission oil and filter pan drop. Since it is not due and not high on my priority list it may be awhile. Zinfendel, as an electrical engineer, perhaps do a bit of research online on these solenoid packs and study how the shifter plate and contact pins works. Let us know where / how you end up! With certainty you will figure out how to troubleshoot and fix yours too. I am a mechanical engineer and I have every confidence I can to it, will do it, the next time I drop the pan on my truck.

 

I've had the output speed sensor on the transmission go out which affects the cruise control. It is a common high mileage failure. Symptoms are as you describe. It may work then drop out and eventually stop working completely.

It may or may not have stored transmission fault codes also.

 

FA and RS, thanks so much for taking the time to post. This information is very helpful and gives me some good ideas of that to look at. Thanks very much.

FA - when your cruise went off due to the gear selector sensor, did the green light go out. If so I presume the N-D shift made it come back on. Have you ever tried the D-N-D shift a couple of times while still driving?

RS - with the transmission speed sensor failure were there any other symptoms, like speedo not working or way out?

Thanks again.

 

No issues with speedometer. Speed is read from ring sensor on rear diff.

 

Yes, the dash cruise light goes out. Just like if you turn it on or off by the steering wheel switch.
No I have not tried shifting the transmission while on a roll. I stop the truck, leave it running, then do the shifting and the CC function comes back. I use the CC so infrequently, thus it is not an annoyance or a priority for me at this time.

Just summarizing the things that I had been through and checked superficially. Basic things that could cause cruise control problems:
- transmission speed sensor at the back
- rear axle speed sensor
- CC solenoid problem or cable problem, depending on model of truck it may or may not have one. The drive by wire throttle bodies do not have a CC solenoid, is all done by the PCM.
- throttle body position sensor faulting
- ABS hub sensor faulting
- intermittent faulty steering wheel CC switches.
- intermittent faulty brake pedal switch
- PCM internal problem
- wiring or connection problems in harnesses to any of the above
- transmission shift position range sensor (problem on my truck to be fixed).

I am happy if you found it helpful in some way.