Intermittent Cruise Control Function

[250_SD_Beast]

I have a 2008 F250 - Job 1 with intermittent cruise control function. Occasionally when I turn on cruise and hit set, it does not come on no matter how many times I push on and set (at or above 30 - 35 mph). Much of the time I can shut my truck down and restart and cruise will work, but not always. Once it is working - I can turn off cruise and restart it and it always works. If I turn my truck off there is a chance the cruise will not start. Anyone have a similar problem?

[FordMudder]

I see it frequently. I use cruise every day to and from work and see it at least once every 2 weeks.

[250_SD_Beast]

Originally Posted by FordMudder

I see it frequently. I use cruise every day to and from work and see it at least once every 2 weeks.

Took my truck in yesterday - turned out to be the brake pressure switch. Cruise thought that the brakes were applied so it would not engage. Took a few hours total to troubleshoot and fix. Seems to work as it should now.

[BeatMarti]

Originally Posted by 250_SD_Beast

Took my truck in yesterday - turned out to be the brake pressure switch. Cruise thought that the brakes were applied so it would not engage. Took a few hours total to troubleshoot and fix. Seems to work as it should now.

I had the same problem. Replaced the pressure switch and it worked for a few hours, then it started again. It turned out that the wire harness connecting the pressure switch was "stressed" to the point that one of the wires got torn inside the insulation and stopped making contact. The pressure switch circuit (when open) reports "pressure on", hence, the cruise control will not come on.

I fixed the harness and all's well since.

[Sirhc7897]

Can you guys steer me in the direction of this harness? My truck has just recently started doing this as well....

Thanks.

[mark turik]

060111,
i have a 2008 f350 with the exact same problem w/my cruise control. his has helped me a lot. i would also be interested in learning more about the wire harness as well as the brake pressure switch.

thanks much folks.
mark turik

[spedyr6]

I have the same problem. It seemed to be worse lately on colder mornings when its cold but not when it was freezing constantly a few weeks ago. Assuming from the above fixes, its just a fluke with the weather. My guess is the switch is connected to the brake pedal and the harness is off of that?

[mark turik]

Originally Posted by spedyr6

I have the same problem. It seemed to be worse lately on colder mornings when its cold but not when it was freezing constantly a few weeks ago. Assuming from the above fixes, its just a fluke with the weather. My guess is the switch is connected to the brake pedal and the harness is off of that?

thurs. 060211

hi and thanks for adding to my post/problem. i am starting to think (from reading), that the problem is in what is called the "brake pressure switch". i am also trying to find out where it is located and what it looks like on my truck. i have a 2008 f350, 6.4l diesel. i have read that it may be located near or on the master cylinder.

does any one know where i can find some pictures, schematics, drawings, ect of this thing?

thank you spedyr6 and EVERYone else who has tried to help me!
most gratefully,
mark turik

[FordCustomerService]

Originally Posted by spedyr6

I have the same problem. It seemed to be worse lately on colder mornings when its cold but not when it was freezing constantly a few weeks ago. Assuming from the above fixes, its just a fluke with the weather. My guess is the switch is connected to the brake pedal and the harness is off of that?

I can see why a problem like this would be disconcerting and I recommend speaking with the dealer to set up an appointment to diagnose the concern. Let me know via private message if you would like help with that or would like any other assistance.

Cory

[FordCustomerService]

Originally Posted by mark turik

thurs. 060211

hi and thanks for adding to my post/problem. i am starting to think (from reading), that the problem is in what is called the "brake pressure switch". i am also trying to find out where it is located and what it looks like on my truck. i have a 2008 f350, 6.4l diesel. i have read that it may be located near or on the master cylinder.

does any one know where i can find some pictures, schematics, drawings, ect of this thing?

thank you spedyr6 and EVERYone else who has tried to help me!
most gratefully,
mark turik

I don’t have access to schematics and drawings but drop me a line if you choose to take the truck to a dealer for repairs.

Cory

[mark turik]

fri 060311
hello cory,
i could not find a private email for you in your reply. unfortunately, i dont think i can afford to take my truck to the ford dealership. the cruise control is something that does not keep me from driving the truck safely. i really do miss it however and hope someone will be able to help me in this forum.

thanks cory,
sincerely,
mark turik

[MPD56]

Mark: if you left click on his name in blue writing (FordCustomerService) a window will come down and then click on “send a private message to FordCustomerService”.

As far as the brake pressure switches, there are two screwed in the bottom of the master cylinder and also a switch on the brake pedal, sorry not sure how they are tied to the cruise control. I do know that the cruise control circuits go through self tests and are monitored by the ECM and if there is an error, it will disable the cruise control and produce a diagnostic code that will be stored in the ECM, but won’t produce the MIL or Wrench light. Chances are you might have a code stored and maybe a reader other then a Dealer’s will tell you. Also there are other codes that will disable the cruise control, for example if the EGR valve sticks and the truck goes into “Limp Home Mode”.

[FordCustomerService]

Originally Posted by mark turik

fri 060311
hello cory,
i could not find a private email for you in your reply. unfortunately, i dont think i can afford to take my truck to the ford dealership. the cruise control is something that does not keep me from driving the truck safely. i really do miss it however and hope someone will be able to help me in this forum.

thanks cory,
sincerely,
mark turik

MPD56 is correct that I would need a private message containing your truck’s info that I stated earlier in the thread. With those details, I can look into this further for you. Thank you.

Cory

[loft306]

/me chimes in with another job2 F350 with intermittant cruise controll that was tollerable just shut it off and restart it and it was back .. then about a month after the CabOff it is more not there than it is functional... will check the brake switch and master pressure switch harnesses/pins on plugs

[loft306]

Originally Posted by mark turik

thurs. 060211

hi and thanks for adding to my post/problem. i am starting to think (from reading), that the problem is in what is called the "brake pressure switch". i am also trying to find out where it is located and what it looks like on my truck. i have a 2008 f350, 6.4l diesel. i have read that it may be located near or on the master cylinder.

does any one know where i can find some pictures, schematics, drawings, ect of this thing?

thank you spedyr6 and EVERYone else who has tried to help me!
most gratefully,
mark turik

The pressure switch is on the bottom front of the master cylinder with a 2 wire plug going to it it is a tight fit to get in there to play with the harness but the switch should be easy enough to get out with a 7/8" crowfoot and an extension , if you dont got the crowfoot use whatever wrench to loosen it like an 1/8th turn then unscrew it with your hand having the new one to screw rite in though it wont leak much fluid and you shouldnt have to bleed the brakes.