Would cruise control not working cause this?

hmmhoyhoy · 04-20-2010, 04:57 PM

Just had the P0455 come back on. Was off for a whole week after had work done. I had the p0455 come on and I got it fixed, at least I thought. The Cruise control worked before I got it to the mechanic and he "fixed the vacuum leak" and then on my way home from the mechanics I realized the cruise didn't work.

My question is if they fixed the original leak and then maybe messed with something else related to the cruise would that cause the po455 to come back on or does the vacuum system have anything to do with the cruise?

Thanks

02 WJ Overland 4.7 HO

hmmhoyhoy · 04-20-2010, 05:47 PM

bump.............

hmmhoyhoy · 04-20-2010, 07:38 PM

Anyone have any ideas?

ezflip · 04-20-2010, 07:55 PM

What exactly did the mechanic do?

Check out this TSB for that specific code for 02 WJ's http://wjjeeps.com/tsb/tsb_wj_2500102a.pdf

hmmhoyhoy · 04-21-2010, 04:01 PM

The mechanic replaced the evap test port hose, so basically the entire evap harness.

MidniteSquirrel · 04-21-2010, 04:16 PM

If there is a vacuum leak, then yeah... your cruise won't work. Check to see if your hvac system is stuck on the Defrost as well, or kicks to the defrost when you accelerate. It's a pretty good sign of a vacuum leak.

On that same note, this thread can help point you to a spot to look:
http://www.jeepforum.com/forum/f13/v...efrost-779877/

Essentially, sometimes the hose can get loose or fall off what it's suppose to. Simple fix and more common than you think.

**WiCkeDuDe** · 04-21-2010, 04:46 PM

Maybe they bypassed the hose in order to take care of the leak

The vac hose for the cruise control comes directly off the right side of the intake manifold as I remember.

hmmhoyhoy · 04-21-2010, 04:57 PM

I hope its something like that, it just seems like it had to have been something done by the mechanic to cause it, I mean it worked when I pulled up and when I pulled away it didnt work. I guess I will have to play around with it.

Thanks guys

**EisBlade** · 04-21-2010, 06:27 PM

It's possible that the mechanic either knocked a connection apart or inadvertantly caused a crack in a vacuum line other than where he was focused. This sounds like a vacuum leak. Whenever I lost cruise control I also lost the ability to change the A/C or heater air flow from always blasting out the upper dash area. Once I found and corrected the leak I had cruise back and the ability to change air flow.

Cruise control uses a manifold vacuum source. On the 4.0L (I'm not familiar with others) the source port is one of the three that come off the extreme right hand side of the intake manifold. It's easily accessible.

If you look under the hood at the firewall behind the engine, just under the upper edge/lip is a thin plastic vacuum hose that runs left/right. This is the line that contains vacuum used for cruise, and should be connected to one of those three intake ports. Make sure that hose is connected at all points and has no cracks. Mine cracked at a natural bend. To fix it, I cut that vacuum line where it was leaking, and inserted both loose ends into a short piece of small diameter rubber hose.

ezflip · 04-21-2010, 06:58 PM

My cruise doesnt work either. My HVAC works perfect. I was getting the same code as the OP. I replaced every vacuum line under the hood and still had the code and cruise still didnt work. Then I found the TSB I posted above, replaced that vent valve and the code is gone. However, I still dont have cruise control. As soon as I have a few extra dollars, Im going to replace the cruise servo and see what happens.