Xantia cruise control repair

[CitroJim]

it's a strange experience!

It is at first but once used to it it is a thing of sheer unbridled joy..

[Mandrake]

Cruise control seems at a glance to be one of those things that solves a decidedly first world problem, but the reality is that constantly glancing back and forth between the road and the speedo on a long trip to make small corrections to the speed due to changes in grade etc is extremely boring and tedious!

Working cruise control also tickles the gadget lover in me, as well as giving me some satisfaction from having a "small victory" over some of the problems with this car.

As I say, I'm intrigued to see how it works

[Northern_Mike]

I just set mine to 90 and have done with it. It's like playing a video game.

[Mandrake]

I just set mine to 90 and have done with it. It's like playing a video game.

So you'll be buying GTA 5 when it comes out next month ?

[Northern_Mike]

The only devices I have in my house are a Wii, an iPad2 and a Asus netbook!

[addo]

Carouse control shows you just how inconsistently most people actually drive. Fast slow fast slow fast slow...

I augment mine with two actions - flicking it off before I crest the top of a large downhill, then reengaging halfway (or more) down, and using extra pedal to get past the people who get funny about how you keep creeping up to them. Once passed at 40 over, you don't let them worry you again and the cruise resumes its previous speed.

[CitroJim]

Carouse control shows you just how inconsistently most people actually drive. Fast slow fast slow fast slow...

Doesn't it just It is absolutely remarkable but then the general quality of driving in the UK is appalling so it really shouldn't surprise us...

[Mandrake]

The biggest problem with UK driving I've seen (as a somewhat outside observer) seems to be blatant speeding...!

People speed in NZ too of course, but the speed limits there are much more strictly enforced, there are a lot more speed cameras (most of which are hidden from view, or at least were when I was last there) and there are a LOT more police cars roving around on the roads looking for people up to no good. Do 110km in a 100km area and you will very likely get caught by a camera or a police car.

Here you see people doing 70/80mph on 50mph stretches of motorway routinely, in fact 80mph seems to be the average motorway speed regardless of whether the sign says 60 or 70. In 70mph zones you'll often be passed by someone doing over 90 and weaving between lanes.

On the other hand I find drivers here a lot more polite at slower speeds particularly in regards to flashing to let you in when you're trying to turn in or out of a difficult junction or merge into a slow traffic flow. NZ drivers are not nearly as courteous I'm afraid to say...its everyone for themselves at a difficult junction or when trying to merge... if they have right of way they won't give it up...

[myglaren]

On the other hand I find drivers here a lot more polite at slower speeds particularly in regards to flashing to let you in when you're trying to turn in or out of a difficult junction or merge into a slow traffic flow.

Try than in a BMW or an Audry - particularly the Q-series.
You could sit there all day

[Mandrake]

On the other hand I find drivers here a lot more polite at slower speeds particularly in regards to flashing to let you in when you're trying to turn in or out of a difficult junction or merge into a slow traffic flow.

Try than in a BMW or an Audry - particularly the Q-series.
You could sit there all day

Well I had a Xantia in NZ and have a Xantia now, so my country comparison is while driving the same model of car.

[Mandrake]

I have in my possession a brand new electrovalve for the cruise control, so we should have a resolution to this thread quite soon.

It lives! I now have working cruise control.

Fitting the new electrovalve wasn't too difficult with the hose and plug attached before bolting it in place. Rather than just go for a test drive and see if it worked I wanted to test the electrovalves/pump/diaphragm etc properly.

To do this I used a 3 metre pair of speaker wires to help me remote control things while watching the throttle butterfly. I unplugged the ECU and first connected my pair of wires between pins 10 and 1. Pin 10 is power supplied through the cruise switch, pin 1 is the positive supply for the dump valve.

By touching the wires together while under the car I could confirm the clicking of the replacement electrovalve I fitted. Next I directly bridged pins 10 and 1 to keep the dump valve active and moved my wires to pins 6 and 7, which are the earth returns of the vacuum pump and its own electrovalve. (Positive is supplied by pin 1, same as the dump valve)

To open the throttle you simply touch both wires to battery negative at the same time - sure enough the throttle fully opened, taking about 3-4 seconds. If you disconnect the earth for the vacuum pump only, the pump stops and the throttle holds whatever position it had stopped in - this confirms that there are no vacuum leaks in the diaphragm, hoses and electrovalves. If you then disconnect the earth for the vacuum pump solenoid the throttle then closes.

Everything seemed to be in perfect order, so I plugged the ECU in and off I went for a drive. It took a bit of getting used to I have to say! Although it will function down to 25mph its not very practical at 30mph as the engine is too responsive in low gear at slow speeds so its small throttle corrections are plainly obvious in the car pitching back and forth as it increases and decreases the throttle...

However in 3rd/4th at 50mph and above it works absolutely perfectly. The only slight problem is it seems like the normally closed contact (for pulling towards you to cancel) in the console control stalk is still a little bit dicky - I tried to spray some contact cleaner in past the boot but its hard to know where it ended up...sometimes when pressing upwards to activate it you hear a double click of the relay and it goes off again - this is because the normally closed contact which opens when you pull the stick towards you to cancel cruise is momentarily going open as you move the stick up - thus it thinks you're cancelling cruise.

With a bit of use it may improve however, as that stalk probably hasn't been used in years!

I'm a little bit confused about the operation of cruise "resume" though, as its behaviour seems to be inconsistent. What I mean by that, is say that you have set it to 60mph and you have to apply the brake to slow down to 40mph, this cancels cruise control - if I then give it a quick flick upwards sometimes it just seems to activate and hold the current speed (eg 40mph) other times it seems like its trying to resume the previously set speed of 60mph. The slightly dicky switch could be the cause of this inconsistent behaviour.

Which should it be doing ? If I want to reset the cruise to a new lower speed do I press it downwards when resuming, or are up and down the same when resuming ? Is there any difference between cancelling cruise by pulling the stalk forward or by tapping the brake ?

All in all a success though, hopefully a bit more use will see the stalk switch right as I don't fancy taking it out!

[addo]

Speaking as someone who fearlessly tears things apart, the stalk is pretty much a sealed unit. :/

Pulling the stalk is the same as touching the brake. Also either toggling up or down after a momentary disrupt should achieve the same result. To change speeds one of the shortcuts for me is to use the dash switch, which cancels the memory.

[Stempy]

As far as I remember a quick flick up will resume to the previously set speed, a flick down will set the current speed, holding up will accelerate until released and holding down will decelerate until released then maintain the speed at the point of release. A pull towards you will cancel the cruise action.

I often used my cruise control in a 30 limit and didn't experience any jerkiness, it was always smooth at any speed, in fact it was better than the fully electronic control in the C5 in its ability to hold a constant speed.

The stalk control could be a bit temperamental though, so that is probably your issue.

[CitroJim]

Well done Simon

As far as I remember a quick flick up will resume to the previously set speed, a flick down will set the current speed, holding up will accelerate until released and holding down will decelerate until released then maintain the speed at the point of release. A pull towards you will cancel the cruise action.

Yep, that's about it Except I've always used used up on the stalk to set the cruise speed. A quick flick resumes cruise given cruise has not been switched off at the switch and a longer up on the stalk sets a new cruise speed. I've never tried a down on the stalk to set it. Must try that this morning on the way to work..

[xantia_v6]

I think that there is a slight difference in operation between early and late systems.
On my 1997 Xantia, a press up or down (when cruise not engaged) causes a resume to previous speed, but on my 2000 XM, a press up resumes to previous speed, and a press down engages cruise at the current speed.