C5 2.2HDI - TPS sensor query

[mwj666]

Hi all,

While going over my other half's 2002 C5 2.2HDI auto yesterday I noticed that, although the TPS progression is nice and linear, the reading doesn't go above about 88% at full throttle.

After a bit of rummaging about and following the cable, I tracked down the TPS under the fuse box and it seems to have the apparently common problem of the cable having stretched so thats going to be an easy fix

BUT I also noticed in Lexia that there are 2 'hard spot' sensor readings for the TPS as well, one normally-open and one normally-closed. One of these always says 'pressed' and the other 'released' regardless of the position of the pedal - even if I take up the spare play in the cable.

I assume these are supposed to be the ECUs simulation of the 'hard spot' on cars with auto boxes and kickdown cables - so I'd have expected the 'pressed' and 'released' to swap over at full throttle but they don't So I'm now not sure whether I have a faulty TPS anyway

Does anyone happen to know what these to sensor readings *should* do - or is there a 'hard spot' built into the TPS (ie beyond the normal 100% open) and I just didn't pull the cable hard enough to get past it? I am guessing that these readings get fed as an input to the 4HP20 auto box for kickdown?

Thanks,
Martin

[GiveMeABreak]

Don't forget that vehicles with cruise control / speed limiter will also have the emergency speed limit override when you floor the accelerator, on manuals as well as autos.

This probably doesn't answer your questions, but contains some useful information on the TPS and testing it:

http://www.ehow.com/about_5890709_sympt ... ensor.html

[wheeler]

Yes the hard spot is only for speed limiter equipped cars, only found on the MK2 onwards.
The most accurate way to test a TPS is with a 'scope. I must say thought that failure of the cable operated TPS's on the early HDi's seem to be very rare.

[mwj666]

Thanks for the responses guys - and although this is a Mk1 it does have both cruise and a speed limiter function, maybe the limiter was only on the Mk1 Exclusives.

I'll be playing with cable adjustment this weekend and see if getting that right (1/16th free play if memory serves?) sorts the hard spot flags out. If not - well she's had the car 6 years and its not caused her any problems yet, unless its connected with the fact that occasionally the auto box refuses to change up under hard acceleration unless you flick it into 'tiptronic' mode

[wheeler]

Do you mean you have a speed limiter function or overspeed warning ? How do you set it ?
I have worked on literally hundreds of mk1 C5's & never seen one yet with speed limiter function. However I think all models from SX upwards have overspeed warning.

[mwj666]

Good question I'd have to go check the car, I just know there's something in there about speed limiting and she says its a speed limiter (though I'll guarantee she's never used it - ex grass-track racer lol) but whether it's an actual limiter or just a warner I'm not sure tbh. Watch this space

[hayabusa1300r]

My 2001 2.2 Exclusive with ESP has a speed limiter

[GiveMeABreak]

I drove a 2002 2.2 HDi manual (either SX or VTX - can't remember exactly, but definately not an Exclusive or SE) and that also had cruise / limiter functionality.

[hayabusa1300r]

Mind none work at the mo as still haven't sorted the speedo and odometer issues I have.....

[wheeler]

Can somebody that has seen or used a Mk1 C5 with speed limiter (not over speed warning) explain how it operates & works, where the controls are etc. were they UK spec ? Don't think there is any mention of it in the mk 1 handbook either.
In the hundereds of mk 1's ive worked on ive yet to see one with a speed limiter

[daviemck2006]

My mk1 2.2 had a limiter, and my mk2 2.0 had it also. I think, if I remember correctly that the rocker switch that turned the cc on went the opposite way to switch the limiter on, and then drive at the speed you want limited to and hit the resume button on the end if the stalk and that's as fast as you can go, no matter what gear or throttle position. I never really used it, if I did it was in towns as 30 mph. If I was out of town I used the cc.

Sent from my SM-G361F using Tapatalk

[wheeler]

I remember correctly that the rocker switch that turned the cc on went the opposite way to switch the limiter on, and then drive at the speed you want limited to and hit the resume button on the end if the stalk and that's as fast as you can go, no matter what gear or throttle position.

That's exactly how it works on the mk2 (05-08) rocker one way for cruise other way for limiter. however I have never seen this switch on a mk 1 & Citroen service only lists one part number for the mk1 switches.
Are we maybe getting mixed up with how we classify C5 models ? I would call a mk1 a 2001-2005, a mk 2 2005-2008 & a mk3 (or X7) 2008 onwards. I know some people refer to the mk 2 as a facelifted mk1 ?
As far as im aware the speed limiter function only became available on the Mk2.

[GiveMeABreak]

Not quite correct Wheeler - the part listed is 6242 Z9 called CDE Regulat and this is for a 2002 2.2 HDi on Citroen Service. Pic below, filtered using a VIN for a C5 2002 2.2 HDi.

Incidentally, the C5 Facelift MKII actually came out in 2004 and the C5 MKIII or X7 actually came out late 2007 - which is why there has been some confusion in many posts, as it's possible to have a 2004 MKI and MKII and a 2007 MKII and MKIII, but as far as the X7 goes, I haven't actually seen an '07 plate personally.

[wheeler]

Ok then
Mk1 2001-2005 ish
Mk2 2005 ish - 2008 ish
Mk3 2008 ish onwards
Cant say ive seen a mk 3 on an 57 plate either but they may exist.
As far as the switches go on a mk 1 the all use 6242Z9 unfiltered it does not give any other choice.
The mk 2 lists 6242Z8 again unfiltered gives no other choice. The part is listed as reg + speed limit. The Z9 one from the mk 1 is just listed as speed control.
So based on that Im sticking to mk1's were never available with speed limiter function.

[GiveMeABreak]

With respect to Wheeler, I think us others may be getting confused - me included over the issue. The presence of the actual Cruise Control Stalk (as per the diagram) doesn't necessarily mean it has both cruise control and a speed limiter function.

If it is soley the Speed Limiter function we are talking about, then in the diagram above, the stalk on item number 5 is actually only for the cruise control for this model (2002 2.2 HDi 136 Auto Estate). There is no limiter function on the stalk - i.e. it does not switch from 'limiter' to 'cruise'. I think this is where the confusion is and is easy to just use the 'cruise / limit' terminology to refer to the actual stalk, when there are 2 types. One with cruise and limiter on the MKIIs, and the cruise only, on the MK1 as wheeler says.

So Wheeler is right with regard to this as there is no mention of a speed limiting function on the MK1 C5s, they simply have the stalk with the cruise control only fitted on the MK1s.