Cruise & Speed Limiter Fault C5 X7

[GiveMeABreak]

I'm sure I've also read that when these are replaced, they have to be set to the correct position (length) of the old switch when replacing the new ones or else problems will occur.

[bobins]

I'm sure I've also read that when these are replaced, they have to be set to the correct position (length) of the old switch when replacing the new ones or else problems will occur.

There's two types of stop switch available - a manual adjust and an auto adjust - and which one depends on the car (and RPO). For such a simple switch, the procedure for fitting the manual one is a bit involved !

[GiveMeABreak]

Yes Bobins, shows the 2 types on my X7 - but does not show as a replacement part from an RPO - just says there may be either fitted! So without taking the thing off there doesn't seem to be an obvious way of ascertaining which one is fitted - but as you say a lot more involved in setting up the manual version - so that could have a bearing if not fitted right.

[bobins]

The two options are.....

4534 67 SWITCH KIT - UNTIL RPO 12291
4534 71 SWITCH-BRAKE - SINCE RPO 12292

It would seem that "71" is the auto adjuster, and "67" is the manual.

[GiveMeABreak]

The two options are.....
4534 67 SWITCH KIT - UNTIL RPO 12291
4534 71 SWITCH-BRAKE - SINCE RPO 12292
It would seem that "71" is the auto adjuster, and "67" is the manual.

That's why then - only the 4534 67 is coming up on my VIN, removing the filter brings up the other - so seems it was replaced on the later model.

[bobins]

That's why then - only the 4534 67 is coming up on my VIN, removing the filter brings up the other - so seems it was replaced on the later model.

Yep, and looking at the OP's car, it would be the 4534 67 (same as yours and mine) that would be needed - the stop switch with the handy extra length of cable made of gold plated unobtainium which bumps the price up

[uglybanana]

Good thinking on the brake switch but I'd already checked it but forgot to mention it. On the live test it shows brake pedal active or inactive. There are two lines for one primary and one for secondary. If I push the brake down slightly one line will turn to active about half a second or so before the other. I took it for a drive and got someone to watch it as I drove and both the lines stayed inactive until I pressed the brake.

This is why I took it out to check it before getting the lexia. I thought the adjustment might be off or switch faulty inside but the multimeter showed it was ok. After I put it back I twisted it into place but the cable was sort of twisted and looped back over creating tension and after a few days it spun it back around so it popped out and all the warnings came up. I refitted it properly, the warnings on the dash cleared straight away and it's been fine since.

Just out of interest the brake switch wouldn't stop the speed limiter activating would it? The limiter flashes and stays paused no matter what I do in the same way as cruise so if there were any issues with the switch the cruise would not work but the limiter still would?

It's pretty frustrating because it doesn't seem to be any of the common causes.

[bobins]

Bit of a leftfield thought - but there isn't anything under "customer customisation" (or whatever it's called in Diagbox) to turn off the cruise control function, is there ? Uglybanana - if you've not had the joys of delving into the depths of Diagbox yet, there's a whole section for customisation for turning things on and off that may or may not be present on your car.

[Hell Razor5543]

On the C5 Mk1 you can go into the Injection menu, and switch Cruise Control from Present to Absent.

[uglybanana]

Bit of a leftfield thought - but there isn't anything under "customer customisation" (or whatever it's called in Diagbox) to turn off the cruise control function, is there ? Uglybanana - if you've not had the joys of delving into the depths of Diagbox yet, there's a whole section for customisation for turning things on and off that may or may not be present on your car.

I know someone has been in on Diagbox before because it has a history of cleared faults in 2009 and 2010 so it's possible someone turned it off for some reason. I saw that option in the menu but didn't go into it and it seems the next best thing to check so I'll have a look at that tomorrow. Thanks.

[uglybanana]

Just been out to test the presence of the cruise in the configuration and it says cruise and limiter present so it wasn't switched off. I thought I'd try a couple of other things so I did a check while driving for the speed received from each wheel in case there is anything inconsistent but all the readings were the same. Double checked the brake switch function and again that was working ok opening and closing on the screen as it should and disengaging the gear shift lock.

I took it for another drive and looked at the cruise info screen in diagbox. Now at the bottom when stationary it says cruise and limiter prohibited. I would think that is normal while stationary or under 30mph but even when I go above that speed and 4th gear or higher it still says prohibited and doesn't change. When under 30mph the dash says cannot activate speed too low but above that I don't get the message but the dashes just flash so it seems like it's nothing to do with a problem reading the speed as it knows when it's above 30mph.

One other strange thing I noticed but it's probably just a quirk of the software is that is says the clutch pedal is pressed all the time. Being an auto there is no pedal but I took it for a drive again to watch watch happens and the status stays pressed all the time. Probably nothing to do with it but just seemed odd.

Running out of ideas now and thinking a trip to Citroen might be on the cards but I'm not confident they will be able to say what it is or fix it. At least not for any reasonable cost. Would appreciate any ideas on what to try next.

[Hell Razor5543]

That clutch pedal issue is very odd, and probably the cause for the CC issue. On my C5 the CC will only work over a certain speed (40MPH, I believe), and only when in fourth or fifth. It will disengage if either the brake or clutch pedal are pressed, the CC is switched off, of the dis-engage button is pressed.

[GiveMeABreak]

That clutch switch issue doesn't sound right at all - would explain why the cruise won't engage on a manual - but not on an auto - I wonder if a setting has been changed in the depths of Diagbox by the previous owner / mech., that is causing it to behave like this. At the end of the day they are computers and are logical - if an incorrect value or parameter has been entered accidentally or otherwise it would certainly help explain why it won't engage. The question is what though? One way to help eliminate any anomalies would be to undertake a Diagbox comparison with another X7 owner with an Auto box, either via the phone or using printouts of each screen - a bit arduous, but if you were to look at the most obvious places first, that might be one way. Citroen would have to charge the labour to do this and there probably won't be any guarantee they would know what to look for - it's not the same as following a fault diagnostic tree! If you were to say focus on the transmission area that might at least eliminate any inconsistencies. I would help, but don't have an auto, but if there are any other settings you want me to compare, just shout.

[uglybanana]

That clutch pedal issue is very odd, and probably the cause for the CC issue. On my C5 the CC will only work over a certain speed (40MPH, I believe), and only when in fourth or fifth. It will disengage if either the brake or clutch pedal are pressed, the CC is switched off, of the dis-engage button is pressed.

It does seem strange that it says that on an auto. I don't know it's just redundant circuitry and wiring being picked up by diagbox or if there actually is a sensor of some sort sending that message. I've a quick look in the service docs and wiring diagrams and can't find anything that points to a sensor or why it would pick that up.

[GiveMeABreak]

I've been scanning back through the thread and can't find it so apologies if you've already tried - but have you gone into the Engine ECU and made sure it is enabled there as well as the BSI? There were 2 places it had to be set on the facelift mark II - can't say if it's the same on the X7 - could be worth a quick check to see if the parameters are right (just in case they have been accidentally changed in a previous session / by previous owner).