Cruise control stopped working

[worane]

My cruise stopped working on the way home today.
I have checked fuze # 30 and it is OK.
Has anyone got any clues where to go with this now?
The light on the right hand side of the steering is still lit.
It is a nuisance as I like to use the cruise a lot.
Any help would be very welcome. ( It is a1999 auto td5 disco)

[simonl8353]

My guess it the rubber vacuum hose from the diaphragm. $2 fix if you buy a piece of rubber hose from Supercheap or similar. Do a search, I posted something on this site a few years ago when I fixed mine.

update... found that post, see here
http://www.aulro.com/afvb/961637-post15.html

[onebob]

.................................................. ......................
onebob

[OffTrack]

From memory worane drives a Td5 Auto I think we can probably discount the possibility of a leaking vacuum hose.

Not 100% if the light on the binnacle switch actually reflects if the ECU has registered that CC is enabled or if it just reflects that the button is engaged. I suspect it's just a tell-tale triggered by pushing the switch.

The most common thing that will drop you out of CC on the Td5 is the brake switch, so have a look and see if the brake lights are on.

cheers
Paul

[Mattblack59bus]

Lastly check the horn still works, the cruse control buttons send 12v from the horn cct to the cruse ECU. If the horn fuse is blown there is no set or resume functions.

Cheers
Marc.

[tailslide]

My cruise control has also recently stopped working in the same way. D2 V8, haven't looked at the brake switch yet. I assume there is a dedicated switch on the brake pedal separate from the brake light switch. Probably should consult Rave...

Cheers
Ron

[Collins]

Quite possibly the vacuum pump has failed, or actuator diaphragm.

[Rok_Dr]

Also check the brake light fuse. The cruise on my td5 dropped out last month towing and I traced it to a blown fuse.

Cheers

Steve

[worane]

Thanks for all the advice. Will check brake switch horn etc tomorrow.
It is a TD5 auto. Not sure by your answers, if it has vacuum pipe on this cruise or not?

[OffTrack]

Thanks for all the advice. Will check brake switch horn etc tomorrow.
It is a TD5 auto. Not sure by your answers, if it has vacuum pipe on this cruise or not?

The vacuum pipe is a v8 thing, so you don't need to worry about that. The td5 CC is part of the ecu and all done electronically.

Apart from the brake switch the only other thing external to the cc switches is that the auto has to be in drive. If you've been having xyz switch problems that might be another thing to look at.

Did you end up buying a Nanocom? The engine ecu module lets you check the CC switch state which would make it easy to identify if the problem is in the switch wiring.

[harps]

Check your brake light fuse. Fuse 25 from memory.

[worane]

Hi Offtrack. No I didn't get a nanocom yet. but have access to a pro job in Geelong.
Thanks for clearing up the vacuum pipe thing.
I have today started having an M&S problem again. I can start in neutral without the m& s coming on but not in park.
The last M&S fix I had was to remove an clean the plug on top of the gearbox going to the XYZ switch. that has been good for at least a week, until today, then the cruise thingy.
Will look at the brake lights in the morning.. Thank for your imput.

[OffTrack]

Hi worane,

Given that the m&s lights and the cruise control problem have arrived together, there is a pretty good chance the m&s fault is the root of the problem.

Definitely check out the easy things like the fuses and brake lights first to eliminate them as suspects but you'll really need to get the car hooked up to diagnostics.

I'd check the following things when you get it hooked up. Descriptions are pinched from the BBS site.

Td5 ECU > switch inputs:
Brake Switch 2: This displays the state of the footbrake pedal brake switch 2 as seen by the TD5 ECU. This switch is only fitted to vehicles equipped with cruise control. Failure of this switch would disable cruise control. It should show OFF with the Brake pedal depressed and ON when the Brake pedal is released.

Cruise Control Master Switch: This displays the state of the cruise master switch as seen by the TD5 ECU. This switch determines whether cruise control can be activated. When the value shows ON, the cruise control is switched on and cruise control can be activated. When the value shows OFF, the cruise control cannot be activated.

Cruise Control Resume: This displays the state of the steering wheel mounted resume/off switch as seen by the TD5 ECU. When this switch is depressed, if a cruise speed is set, cruise control is disabled. If cruise control is already disabled when this switch is depressed, cruise control will be re-enabled, providing that a valid cruise speed was previously set. The value should show OFF with the resume/off button released, and ON with the resume/off button depressed.

Cruise control Set Accelerate: This displays the state of the steering wheel mounted set/accelerate switch as seen by the TD5 ECU. When this switch is depressed, the cruise speed is set to the current vehicle speed, providing the conditions for cruise are met i.e. brakes released, gear engaged and road speed above minimum cruising speed 28mph (35 kph). If cruise control is already active when this switch is depressed, the required cruising speed is increased by 1mph (1.6kph) increments up to a maximum of 100mph (160kph). The value should show OFF with the set/accelerate button released and ON with the set/accelerate button depressed.

Gear Switch: This displays the current state of the park/neutral or drive selection switch in the automatic gearbox. The state is transmitted from the gearbox via the CAN link. Failure of this switch in the drive position would prevent starting of the vehicle. If the vehicle is not fitted with an automatic gearbox, then this value should be ignored.

The big advantage of checking these switch values is that you can push the buttons or change gear selection and see if the ECU is responding correctly, so you can eliminate suspects from the list very quickly.

The gear switch setting is determined by the Auto Box ECU from the inputs from the XYZ switch so this will be an easy way to determine if the M&S fault is causing the CC issue.

You should also get the fault codes checked on the Auto Box while you are there. If you can get a list of the full code description and fault number(s) from the techs that should help id the M&S issue.

cheers
Paul

[worane]

Well, today I went out and pulled all fuses,all OK.
Tested horn OK,went for a run. No M&S lights and the cruise is working.Go figure? I sometimes thing this truck really does have a life of it's own.
When I was out yesterday we did a little bit of off road moderate fire trail work. Being the garage queen that this thing is becoming, maybe it " cracked the sterks".
Thank you everyone , for you help with this matter. It really is great to have so much help from such a knowledgeable bunch of like minded friends.
Some of us just starting to unravel the quirks of this great little truck would be stuffed without your help. Thanks
Regards Nick.

[OffTrack]

Well, today I went out and pulled all fuses,all OK.
Tested horn OK,went for a run. No M&S lights and the cruise is working.Go figure? I sometimes thing this truck really does have a life of it's own.
When I was out yesterday we did a little bit of off road moderate fire trail work. Being the garage queen that this thing is becoming, maybe it " cracked the sterks".
Thank you everyone , for you help with this matter. It really is great to have so much help from such a knowledgeable bunch of like minded friends.
Some of us just starting to unravel the quirks of this great little truck would be stuffed without your help. Thanks
Regards Nick.

Nick,

It's not exactly what I'd call a "quirk". I suspect you still have an intermittent fault somewhere between the xyz switch and the Auto Box ECU. From the series of events you've reported I think it's safe to assume the cruise control problem is just a symptom of the gearbox fault.

Given you've had problems with auto harness connectors recently I'd think the problem wasn't actually full sorted, so you might need to revisit if the m&s recur.

The m&s fault will leave a logged fault in the ECU so if you get the car hooked up at some stage you'll be able to ID what caused the issue.

Add: Searching back on your posts I found that you'd had m&s issues in late 2012 that were apparently caused by the harness rubbing on the top of the gearbox. I'd have a sneaking suspicion that some of the harness wires have been damaged by the rubbing and you are getting intermittent faults due to movement in the harness. If the M&S return I'd suggest you pull the auto harness and carefully check continuity while gently flexing the harness at the rub point.

ADD2: If you have time try hooking up with a member with a Nanocom to check the codes on the Autobox ECU. There is a member listed in Geelong but he hasn't responded to a PM sent last December asking for confirmation of details for the Members with Diagnostic Tools list. Next closest is probably alien (Bacchus Marsh), and then myself (Brunswick West).

cheers
Paul

[justfishing]

Hello,
I had the same problem with the cruise control after lots of time and looking I replaced the brake switch on the pedal never a problem since I found out this as if I took it off gave it a clean replaced no problems so got a new one went great after that. Have you flashed your ECU lately ?? As this can do it as well.
Ian

[worane]

Geez Paul, you do your homework.
I think the same as you about the harness but having pulled the plug to the XYZ socket a while back the harness is still encased by conduit and should be unworn. I figured the prob was oil in the plug socket which was cleaned out.
Main problem is that I an relying on a commercial premises to use the hoist and have little time to really have a good look at things.
Likewise, the computer is owned and operated by an auto gearbox company, though the young fellow seems to know what he is doing.( He owns a V8 disco and they have a dyno on site so he is an enthusiast.)
I just hope it is the plug and not the XYZ switch.
I too have tried to contact the fellow with the Nanocom in Geelong but he has not responded.
I would love to buy my own nanocom but as I'm now retired, I have limits on my fiscal liberty ( I'm married)!
Regards Nick

[disco2_dan]

My guess it the rubber vacuum hose from the diaphragm. $2 fix if you buy a piece of rubber hose from Supercheap or similar. Do a search, I posted something on this site a few years ago when I fixed mine.

update... found that post, see here
http://www.aulro.com/afvb/961637-post15.html

X2
This was what was wrong with mine

[justfishing]

hello,
Sorry I must have very blurred vision this morning I didn't see yours is a V8....I have a TD5......
Ian

[D2V8]

My guess it the rubber vacuum hose from the diaphragm. $2 fix if you buy a piece of rubber hose from Supercheap or similar. Do a search, I posted something on this site a few years ago when I fixed mine.


+1 for a first check of this..

this was the problem and fix that I had.. believe that it was probably your orignal post that help me ID it back then to..

was a bit of fiddly position but worked like a charm.. :BigThumb:

[worane]

D2v8 I own a diesel TD5!!!
You are a little off track.

[tailslide]

My cruise control has also recently stopped working in the same way. D2 V8, haven't looked at the brake switch yet. I assume there is a dedicated switch on the brake pedal separate from the brake light switch. Probably should consult Rave...

Cheers
Ron


Well after 2 years and 50,000kms I decided to have a closer look today:




https://www.aulro.com/afvb/images/imported/2015/05/8.jpg


And found this split hose:


https://www.aulro.com/afvb/images/imported/2015/05/9.jpg


Happy to report that cruise control is now working again. I probably could have looked at this sooner but you don't need to rush into these things now...


Cheers
Ron

[discotuner]

My cruise stopped working on the way home today.
I have checked fuze # 30 and it is OK.
Has anyone got any clues where to go with this now?
The light on the right hand side of the steering is still lit.
It is a nuisance as I like to use the cruise a lot.
Any help would be very welcome. ( It is a1999 auto td5 disco)

I had this problem for a while, Then I would remove brake switch clean it all good till the next time so I brought a new brake switch and problem solved. Usually the rubber pipe is on the V8's I believe.
Discotuner