Frustrating Cruise Control

[piper109]

www.modulemaster.com

Try this link for $6 shipping otherwise they want $12 shipping

http://cgi.ebay.com/ebaymotors/ws/eBayISAPI.dll?ViewItem&item=270414281347&ssPageName=STRK:MEWAX:IT

 

[adumee]

Had lots of cruise control trouble myself it both my Land Rovers.

I have added a small spacer between the Brake contact point to the switch and it now fully depresses each time when the brake in not applied. Flimsy holder can give you different outcomes depending how the contact was made.

Also I have noticed that when starting the car on a somewhat low battery, multiple ecu's do not operate properly. Switching off then on main cruise control switch fixes my problem once running.

Same goes for engine ecu. start on low battery and you will experience high idle at stand still. restart once battery has recovered all is fine.

Hope this helps.

 

[piper109]

Had lots of cruise control trouble myself it both my Land Rovers.

I have added a small spacer between the Brake contact point to the switch and it now fully depresses each time when the brake in not applied. Flimsy holder can give you different outcomes depending how the contact was made.

Also I have noticed that when starting the car on a somewhat low battery, multiple ecu's do not operate properly. Switching off then on main cruise control switch fixes my problem once running.

Same goes for engine ecu. start on low battery and you will experience high idle at stand still. restart once battery has recovered all is fine.

Hope this helps.

I noticed that before I had mine repaired. It was intermittent. Now since repair however it does not seem to be sensitive to that.

 

[d1driver]

Steve - where exactly is the cruise ECU? Which one behind dash? Mine works, then doesn't, then works again. Telling me its an electrical and not mechanical issue.

 

[piper109]

You have to remove the glovebox and its in behind, approx right of center.
The plug faces downwards slightly and its held in by two M6 nuts (10mm wrench), one of which is a pain to remove. Its a silver box, old fashioned looking, inserted like a book on a shelf.

Steve

 

[no694terry]

mine only works below 35mph

 

[d1driver]

Ok, so I bought a replacement ECU hoping to solve my problem, and nope, didn't fix it. The interesting thing is it would work for a while on highway, then drop out a couple weeks ago. Now, it doesn't do anything.

I did remove the brake pedal switch and tape it in, to see if it changes anything. It didn't. Also took vacuum line off brake switch and tried to see if it was getting any vacuum when trying to set cruise at speed, and there is no vacuum. I have not changed the lines, but if I suck in on them at the pump up front, it holds the can thing on the throttle body in and holds it there.

So, I have replaced pump up front and ECU. No help. What's next? I have no idea where my rave is, but is there an easy way to test it without the rave? I HATE throwing electrical parts at problems.

 

[piper109]

If it was working and now doesn't in my opinion there is a 90% chance that the ECU needs repair.
There are 3 items that are famous for causing problems:
1 vacuum hose dry and broken
2 dodgy/dirty switches on the steering wheel
3 defective ECU
Mine did exactly what you describe and after going over everything in Rave multiple times, I sent off the ECU for repair.... $70 end of story.

Steve

 

[d1driver]

Tomorrow, I am going to replace all the vacuum lines and see if it changes anything.

By the way, the engine is running great! No problems after 5k miles!

 

[fishEH]

Tomorrow, I am going to replace all the vacuum lines and see if it changes anything.

By the way, the engine is running great! No problems after 5k miles!

Sounds like my problems exactly. I replaced all my vacuum lines, too. Didn't make a bit of difference.
I looking forward to you resolving this so you can tell me what I need to fix.

 

[d1driver]

Looking to buy a couple more items from Will. That will equal me having changed all of the parts! Going to change one at a time and test it, to see if I see a change.

 

[piper109]

Glad to hear engine is running well. It did for me. Real smooth. Fortunately the 300tdi is running great too.
I have bought a "working" cruise ECU from Will also. It worked a couple of times then nada. It seems they all go bad. There must be some component that degrades with time and the place in Moscow Idaho replaces it.
My advice is dont mess with another used one. I had 3 bad ones.
Now I only have 2 bad ones and one repaired working one.
Send it off for repair. It will be one less item to trouble shoot and chances are its your real problem anyway.

Steve

 

[taskforce121]

Hey guys, just curious but with a non functional CC of my own, I have checked all the stuff you guys have gone through (although I don't know how to verify the module is either good or bad) and I keep coming back to the switches on the steering wheel. I even swapped the button on the dash that turns the CC on, to no avail. It seems to me if the switch on the wheel worked off and on, it would give the same error profile as the other items, but no one seems to mention that piece of the puzzle. Am I missing something, or does fixing that piece require so much from a labor standpoint, that noone goes there.
just wonderin"

phil

1967 SIIA
1994 and 1997 Disco I

 

[piper109]

Its easy to check the steering wheel switches.
I dont have my cheat sheet in front of me right now to give you the numbers but essentially with the cruise and ignition switched on, you can detect 12 volts at the ECU connector on the appropriate pins when the switches are pulled.
If you dont get reliable strong 12 volt signals, take the switch apart and clean it up with something like de-oxit and use dielectric grease on the contacts.
I found the only way to be sure about the ECU was to get it repaired and the more I hear about these ECU's the more I believe they die with age and frustrate people and most people leave them non-operational.
It seems too that buying a used one is futile. They might work but not for long:banghead:.
If your hoses are good, the switches clean and all the input signals check out then the ECU is the culprit.
I regularly do the same 200 mile trip and I like mine to work!

Steve

 

[DCDisco]

Easiest thing to do is buy a nice sedan for long trips. Lexus are much better on the road than a Discovery. I can't even remember the last time my cruise control worked on the Disco. MTs + 8mpg + lift + 75mph top speed = local trips only.

 

[no694terry]

Easiest thing to do is buy a nice sedan for long trips. Lexus are much better on the road than a Discovery. I can't even remember the last time my cruise control worked on the Disco. MTs + 8mpg + lift + 75mph top speed = local trips only.

I loved my 300M on road trips, put 170k miles on it, several cross country trips. only needed to change one engine, two transmissions, everything else mechanical, turned or held fluid but atleast all my electrics always worked.

8mpg too, just put the 32's on and the lift, i filled up the other day and currently down to a quarter tank with only 124 miles on it.

 

[DCDisco]

Yeah, Mopar/Chrysler is one of the few suppliers that makes Lucas/Hella look good.

I had an Acura Legend Coupe that had 250K on it when I sold it 10y ago and I still see it driving around town, same stickers on back. I bet that thing has 500K+ on it, with everything still working. I bought it new in '89 and only thing I ever did to it was CV joints and plugs.

 

[piper109]

Easiest thing to do is buy a nice sedan for long trips. Lexus are much better on the road than a Discovery. I can't even remember the last time my cruise control worked on the Disco. MTs + 8mpg + lift + 75mph top speed = local trips only.

Well I regularly drive 200 miles up into the North Carolina Appalachians and I need 4 wheel drive up there especially in the snow and ice they presently have.
I'll admit that my Disco is not the quietest and smoothest but I do get 22-23 mpg on that run and cruise at 75 plus most of the way.
The 300tdi makes all the difference. I really appreciate a functional cruise control.

Steve

 

[ptschram]

Has anyone looked at the relay?

I've fixed countless cruise controls and have yet to encounter a bad ECU.

Lots of bad vacuum lines, some bad switches on the steering wheel, occasionally the pump, occasionally the relay, but NEVER the ECU.

BTW-the relay is special and is the only application on the truck for that relay.
edit-nobody did a search did they? Many discussions on this topic previously.

 

[jymmiejamz]

I've fixed countless cruise controls and have yet to encounter a bad ECU.

Lots of bad vacuum lines, some bad switches on the steering wheel, occasionally the pump, occasionally the relay, but NEVER the ECU.

That's strange, I've replaced at least 5 ECU's, which is a lot considering how many D1's we see nowadays.