Warning fitting tow bar to Citroens equipped with ESP

N

niks

Member
Fellow Frogger
Joined
Dec 15, 2010
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225
Location
Melbourne
Have just had my wiring loom changed by Citroen dealer to a genuine one from Citroen France.
Citroen Australia have been supplying a bypass system as genuine, also (the towbar is not genuine but will do the job) and claiming its because of ADR's well this is a fallacy as these cars come under the EEC regulations not ADR's and are accepted here by the ADR regulators.
If you fit a non genuine wiring loom you run the risk of an accident if your caravan starts to weave from side to side. The car computer will not know that it has an extra load on behind it.
The genuine loom when fitted and has lexia connected will be programmed into the system and when you hook up the load on behind it lets computer know and it will activate what is generally known as TSP. If the load on behind starts to weave from side to side the ESP takes the appropriate action to bring it under control before an accident occurs. Fitting a genuine tow bar will eliminate having to cut your rear bumper. It appears to me that it has all come down to price so the choice is yours fit non genuine and take your life into your hands or have genuine fitted and be safe. Interesting that Citroen Australia don't mention the fact that fitting a non genuine accessory will void your warranty if it caused a problem and possibly your insurance company would also void your claim if the tow bar and wiring was the cause of an accident. I also feel that importers are using a loop hole in ADR regulations, I intend taking this matter up with them. So if your thinking of getting a genuine towbar and wiring check it out and make sure it is genuine, ask to see it before installation and check the part numbers. If you wish to do it yourself we have an importer in Gold Coast who imports genuine parts and wiring looms. but must be 13 pin not 7 pin. why because 13 pin has a micro switch that disables the reverse sensors and lets the computer know a load has been connected.
Hope this information prevents someone from having a accident.
 
Groan - another trip back to the dealer

I bought a tow bar with my C5 Tourer almost 3 years ago and did realise that they had fitted a aftermarket solid state relay system for the trailer lights. I thought this was OK until your post. Luckily I have only used it so far to take the box trailer to the dump a few times (and up to Noosa once) but I do have plans to get a bit more serious in the future to as much an extent that the paltry tow ball weight rating will let me. I had realised that there was a problem with the reversing sensors but I hadn't twigged to the ESP type issues. SERIOUS INDEED.

So we do need to get this resolved with Citroen Australia. How should we go about that? I will have a chat to Adrian the Service Manager at Brisbane Citroen tomorrow and see how he reacts. Luckily I have a few months warranty remaining.

Cheers,

Ken W
 
niks said:
If you fit a non genuine wiring loom you run the risk of an accident if your caravan starts to weave from side to side. The car computer will not know that it has an extra load on behind it.
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hi, do you think this means that the ESP just doesnt help, or that the combination of ESP and improperly connected trailer makes the whole thing less stable than simply towing a van without stability control at all?

i dont have an affected car; just curious.

thanks
alexander.
 
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Interesting concepts at work here.

I believe a well designed and loaded trailer driven within the capabilities of the vehicle and the drivers skill does not get into trouble.That is a prety universal concept.



I wonder if all this technology is a good thing or just allows under skilled drivers to attain a much higher speed before the shit hits the fan.

One thin I know as a fact; nothing makes you slow down like a taste of swaying trailer.:eek:
I'd hate to have it happen beyond the speeds where the driver/esp/tsp can cope.




Jo
 
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jo proffi said:
Interesting concepts at work here.

I believe a well designed and loaded trailer driven within the capabilities of the vehicle and the drivers skill does not get into trouble.That is a prety universal concept.



I wonder if all this technology is a good thing or just allows under skilled drivers to attain a much higher speed before the shit hits the fan.

One thin I know as a fact; nothing makes you slow down like a taste of swaying trailer.:eek:
I'd hate to have it happen beyond the speeds where the driver/esp/tsp can cope.




Jo
Click to expand...

A blown tyre for example can cause the sway and the tsp will will respond far quicker than any driver can regardless of his skills. Also a trailer is easier to control than a caravan as its sudden gusts of wind that is usually the problem with towing a van or large boat regardless of how you loaded it. I believe there is a video on you tube explaining it further with car and van.
 
niks said:
A blown tyre for example can cause the sway and the tsp will will respond far quicker than any driver can regardless of his skills. Also a trailer is easier to control than a caravan as its sudden gusts of wind that is usually the problem with towing a van or large boat regardless of how you loaded it. I believe there is a video on you tube explaining it further with car and van.
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Yes, but the computer needs to know the dynamics of the vehicle. If you change it with a load behind, it needs to modify its parameters otherwise it can fail to stabilise.
This is yet another example of the current technology demanding that you use the parts approved by the manufacturer like the oil and tyres, even coolant.
The stability issue is in no way confined to Citroën. It is common to all ESP systems (which are now mandatory in Europe).

The manufacturers can't be overjoyed with having to provide facilities for towbars because they compromise the crash tests and the stability controls. In France I am seeing less and less ordinary sedans towing anything bigger than a trailer for the tip.
My car handbook very specifically states that it is not suitable for towing and there are no provisions for a tow bar, so there!
 
gerry freed said:
The manufacturers can't be overjoyed with having to provide facilities for towbars because they compromise the crash tests and the stability controls. In France I am seeing less and less ordinary sedans towing anything bigger than a trailer for the tip.
My car handbook very specifically states that it is not suitable for towing and there are no provisions for a tow bar, so there!
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I was not talking about your car as I dont know you or what you drive.

Given most Europeans drive very small cars i agree with your statement of towing trailers but a car the size of my C4GP does have provision for a tow bar and is capable of towing a caravan.
Why are you trying to shoot the messenger instead of understanding the purpose of this information posted. Re compromising crash tests well that is the purpose of TSP etc to tell the car it has a load on behind and can therefor use the ESP system to enable safe control of the car and van in situations beyond the drivers control.
If they felt their crash tests were compromised by towing they would not put the fittings to enable this to be done and also would not sell genuine tow bars and wiring looms. The problem is that dealers want to make a quick buck by selling systems with a bypass loom to avoid having to pay someone ie a tow bar fitter to fit a genuine system as it takes two hours or more to do,a bypass system is up and running in an hour.
 
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Folks,

Can any one find clear documentation from Citroen or PSA that the Citroen ESP as fitted to C4 and C5 vehicles has a Trailer Stability Program option that is auto-enabled when a trailer in connected via the factory loom?

I have been googling quite hard and have found quite a few other makes that document this as a feature but most of the mentions with Citroens are more assertions from owners that this feature would be present and the dangers of not using a factory loom.

Cheers,

Ken W
 
I wouldn't be surprised if it simply disabled the ESP when towing.

You have to wonder what sort of drugs the designers at PSA are on. Citroen C5 station wagon .... V6 turbo diesel ... "big family car" ..... can tow what 1200kgs with a stupidly pathetic 60kgs on the drawbar.

Yet a tiny manufacturer in the scheme of things (ford australia) can build a family station wagon.... the territory. The Citroen V6 turbo deisel in it .... 6spd gearbox that likely wont' die for no reason like every PSA car,, AWD.... And a person that's not on drugs that designs the tow rating. 2.7 tons ... yes not a typo, 2700kg and 270kg on the drawbar ... ie: 10% of the towed amount.

I guess these days we get useful things like "perfume dispensers" from PSA though :rolleyes:

seeya,
Shane L.
 
Ken W said:
Folks,

Can any one find clear documentation from Citroen or PSA that the Citroen ESP as fitted to C4 and C5 vehicles has a Trailer Stability Program option that is auto-enabled when a trailer in connected via the factory loom?

I have been googling quite hard and have found quite a few other makes that document this as a feature but most of the mentions with Citroens are more assertions from owners that this feature would be present and the dangers of not using a factory loom.

Cheers,

Ken W
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I have only found that the c4 and c5 have warnings on the wiring not to cut into them as you would do with a bypass system and given the fact that the genuine kit involves a lot of work installing it and its module to ensure lights and indicators become part of the can ban system and when you connect the lexia on completion as advised in the instructions with the kit you have to select program of activating the towbar wiring fitment which lexia does and tells you when its completed. This problem in Australia also exists with other European brands/models where the booklet tells them it has to have a genuine system for the activation of TSP or whatever the manufacturer calls it . The dealers response is that they must comply with our ADR's which is wrong as EUROPEAN cars are accepted under EEC regulations, its a loophole as we are talking accessories not the car itself, so accessories that affect safety would also come under EEC regulations ADR's do not apply as claimed by dealers.
 
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I checked in the spare tyre well of our C5 yesterday for the towbar module. It is a Bosch part but also with PSA branding.

And Shane, the reason Euro manufacturers have these towball restrictions is not only to do with downforce but it is also a regulation to restrain people from driving a vehicle over the legal maximum towing weight of 3.5 tonnes.
 
niks said:
I was not talking about your car as I dont know you or what you drive.

Given most Europeans drive very small cars i agree with your statement of towing trailers but a car the size of my C4GP does have provision for a tow bar and is capable of towing a caravan.
Why are you trying to shoot the messenger instead of understanding the purpose of this information posted. Re compromising crash tests well that is the purpose of TSP etc to tell the car it has a load on behind and can therefor use the ESP system to enable safe control of the car and van in situations beyond the drivers control.
If they felt their crash tests were compromised by towing they would not put the fittings to enable this to be done and also would not sell genuine tow bars and wiring looms. The problem is that dealers want to make a quick buck by selling systems with a bypass loom to avoid having to pay someone ie a tow bar fitter to fit a genuine system as it takes two hours or more to do,a bypass system is up and running in an hour.
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I am not shooting the messenger at all. I am fully in agreement with you, this is a danger like a number of others that can arise with contemporary cars if you do not fit the manufacturer's approved parts.
You cannot expect that the dynamics of a 1.5 tonne rigid object to be the same as a three tonne object with a hinge and neither should the algorithm that stabilises sideways forces in the electronics.

I am merely commenting that it is a pain for the manufacturers of urban cars to have to provide facilities for a tow bar, when so few use them. That may not be true in Australia but here in Western Europe they are less and less used. When people want to tow anything now they tend to use a 4wd or SUV. Caravans are still being sold but have given way to mobile homes. My Honda reflects this trend as the makers are quite content to offer an urban car without towing facilities. After seeing the XM's in the UK written off just because they have had a minor ding on the tow ball, I can see the compromises. When you have a rear shunt on a current car, the plastic bumper deforms first. When you have a tow bar on it the odds are it crumples the boot floor or rear structure and the repair costs have three zeros instead of two.
If I want to tow anything I borrow my neighbour's Nissan 4wd. Hard wired, no ESP and a solid frame on which the factory standard towbar is mounted. In Australia I towed my 1920's C3 5HP on its custom trailer behind my XM. Here I wouldn't try that on a C anything!
 
Does anyone know how the car would react if the right electronics is installed, with the 13-pin, but not enabled through the Lexia?? I had the dealer put the electronics in but reversing sensors and fog lights keep on being activated when plugging in a trailer (with the 13-pin so tripping the microswitch).

Thnx

Dennis
'15 C4GP
 
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