C5 Steering

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Empin
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C5 Steering

Post by Empin » 11 Nov 2018, 10:14

Hello everyone. Just joined after 16 yrs of C 5 ownership so new to this not to the cars.
We bought the first new and over twelve years put 170000 nearly fault free miles on it . We replaced this with a MK3 tourer which after three years we have never actually settled into. The reason is that the steering is very unrelaxing being too light. This is OK around town but at anything above 30 you lose contact with the wheels so as to speak. I reconditioned the rack having suffered the rusty input shaft but that didn't change anything. It's the electric pump in the wheel arch and I would like to know if it has a software cure or spanner cure. I am used to working on hydraulic circuits so not phased by the idea. Can anyone help please?
TIA

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KennyW
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Re: C5 Steering

Post by KennyW » 11 Nov 2018, 10:58

Welcome to the forum,


Was the rack like that when you bought or has it happened after reconditioning your rack ?

Kenny

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GiveMeABreak
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Re: C5 Steering

Post by GiveMeABreak » 11 Nov 2018, 10:58

Empin wrote:
11 Nov 2018, 10:14
It's the electric pump in the wheel arch and I would like to know if it has a software cure or spanner cure. I am used to working on hydraulic circuits so not phased by the idea. Can anyone help please?
TIA
Hi and welcome.

Nothing you can do unfortunately - the GEP ECU is programmed with specific parameters according to engine and model.

The electro-pump provides a sufficient assistance output when it receives the engine running information from the internal combustion engine.
The minimum speed of rotation of the electropump assembly is 1000 rpm.
Several parameter settings can be programmed in the electro-pump to optimise the output in relation to the engines and vehicles.
The electropump assembly output is referred to as the "Stand-by output" when the vehicle speed is 0 km/h and the steering wheel speed is zero.

The output provided by the electro-pump varies depending on the following elements:
  • The speed of the vehicle (the output decreases when the vehicle speed increases)
  • The speed of rotation of the electropump assembly (the output increases when the speed of the steering wheel increases)
  • The temperature of the power steering LDS fluid
When the temperature of the electropump assembly reaches 125 °C, the electropump assembly stops.
In the event of failure of the electronics:
  • The electropump assembly uses its back-up parameters
  • The electropump assembly switches to back-up mode
So the GEP is pre-programmed to meet engine specifics and is something that cannot be changed by a diagnostic tool.

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Paul-R
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Re: C5 Steering

Post by Paul-R » 11 Nov 2018, 11:35

Hello and welcome to the forum.
Empin wrote:
11 Nov 2018, 10:14
I reconditioned the rack having suffered the rusty input shaft but that didn't change anything.
You mean you physically reconditioned the rack yourself? What did you do about the pitting from the corrosion on the input shaft where the seal runs? Did you use one of those very thin sleeves (I forget the name) and standard seal or possibly some larger seal?

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EDC5
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Re: C5 Steering

Post by EDC5 » 11 Nov 2018, 14:39

GiveMeABreak wrote:
11 Nov 2018, 10:58
Empin wrote:
11 Nov 2018, 10:14
It's the electric pump in the wheel arch and I would like to know if it has a software cure or spanner cure. I am used to working on hydraulic circuits so not phased by the idea. Can anyone help please?
TIA
Hi and welcome.

Nothing you can do unfortunately - the GEP ECU is programmed with specific parameters according to engine and model.


Is this parameter set in Diagbox? Could you not set the GEP to think it only had the 1.6 HDi ?

perhaps then it would provide less assistance?

Empin
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Re: C5 Steering

Post by Empin » 11 Nov 2018, 19:00

Many thanks for the welcome and info
The car was like it when bought and didn't change wheni did the rack. I noticed the leak and saw it was the rack so I popped it off and it was immediately apparent that the spindle was the cause. Having looked for a sensible solution price wise I lost faith in possible suppliers when none asked wheel size.
I took the spindle out and cleaned it thoroughly then used an industrial epoxy to coat it and left it to cure
I then cleaned it up with wet and dry assembled it with two new seals from our hydraulic suppliers and it's been fine for nine months.
OK so I gather the assistance is governed by motor speed? If so is this controlled by voltage as that would be interesting I'm thinking sort of dial a speed controller which would be quite easy.
TIA

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GiveMeABreak
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Re: C5 Steering

Post by GiveMeABreak » 11 Nov 2018, 19:01

EDC5 wrote:
11 Nov 2018, 14:39
Is this parameter set in Diagbox? Could you not set the GEP to think it only had the 1.6 HDi ?
perhaps then it would provide less assistance?
Unfortunately not Elis - factory set and programmed for the specific engine and model - not configurable via Diagbox parameters - only via the PSA servers and then will only programme in the values according to the VIN.

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GiveMeABreak
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Re: C5 Steering

Post by GiveMeABreak » 11 Nov 2018, 19:04

Empin wrote:
11 Nov 2018, 19:00
OK so I gather the assistance is governed by motor speed? If so is this controlled by voltage as that would be interesting I'm thinking sort of dial a speed controller which would be quite easy.
TIA
Not really, there are 2 electronic cards in the GEP ECU and these talk to the BSI and the Engine ECU - any interference will very likely cause you faults elsewhere or for the power steering to go into backup mode. It's not just the speed, but the angle and rate of turn made on the steering wheel by the driver that is also taken into account.

Empin
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Re: C5 Steering

Post by Empin » 12 Nov 2018, 09:23

Many thanks for the info. That's a pity but this steering I'm sure must be faulty as it's far too light at speed meaning the car, instead of being a relaxing tourer, is twitchy and dead feeling with no feedback As soon as you relax you find the car drifting lanes as you only need a pulse in your wrist to move the wheel. It ruins the whole purpose and unlike our mk1 long journeys are not welcome.
Do you by any chance know the working pressure and rated output of the pump as I will try a hydraulic solution which will be cheaper than trying new pump etc
TIA

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Paul-R
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Re: C5 Steering

Post by Paul-R » 12 Nov 2018, 09:36

Could the tracking be out of tolerance? Has it been checked?

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Stickyfinger
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Re: C5 Steering

Post by Stickyfinger » 12 Nov 2018, 10:01

Simple to check, tyre pressures.

Also, maybe you are gripping the wheel to hard, I know it sounds silly but it is a habit "other" drivers have. Citroen = Fingers and toes not feet & fists.

I have run 3 makes of tyre on my C5, all change the feel of the suspension slightly.

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GiveMeABreak
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Re: C5 Steering

Post by GiveMeABreak » 12 Nov 2018, 10:29

There are other factors to consider:
  • Have you changed the wheels for a different size? The Electro pump is set for different wheel sizes and provides different assistance characteristics.
  • Did you thoroughly bleed the hydraulic system after replacing the rack following the official procedure?
  • Are you getting any other fault codes relating to the ABS / ESP system? Any faults can may affect the speed info sent to the GEP ECU
The RPM of the pump varies according to speed, rate of turn of steering wheel and according to wheel size. Min RPM 750, Max 5700, with variations of everything in between depending on the speed and the rate of turn, but also included in this there is a flow strategy to compensate for LDS temperature. I can't see how applying 'a hydraulic solution' is going to make any difference whilst maintaining the safety of the vehicle in all conditions. The system is designed to work with input from the other sensors.

Are you using Diagbox? Have you read the live parameters of the Steering Pump so you can determine what is going on? I'll assume you have a Lexia as you've had C5s for years, because a generic code reader or non-lexia system very likely won't have the detail or capability to deal with the PSA specific codes and the diagnostic procedures.

Empin
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Re: C5 Steering

Post by Empin » 14 Nov 2018, 09:13

Hi thanks for the replies.
Tyres fine can't run to far out or get nagged!
The tracking seemed irrelevant as when I had done the rack there was a small bias so I set it again by eye and went on holiday. Exactly the same, had it done 4 wheel on return and no difference (eye wasn't far out).
I never had the need for a lexia as apart from the odd bit such as MAF sensor nothing much went wrong until the turbo failed at 160000. Bloody awful job but easy to diagnose.
An ESP fault showed after changing the rack but I put that down to breaking a brake wear wire and can't be bothered doing it until new pads are warranted. Again no difference.
I can see a hydraulic solution is going to be difficult and wonder if our car has been faulty from day one. We just thought it was different from the old one and we would get used to it but no its like driving on ice with no sense of attachment to the front wheels at all. Cars a 1.6 tourer exclusive do I just wonder if the wrong pump is on. Are the other engine options heavier.?

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Re: C5 Steering

Post by Empin » 14 Nov 2018, 09:20

Just thought one fault from day one is that it suffers intermittently from 'kangaroo petrol' in slow traffic with the throttle having no finesse either on or off. Very unrelaxed may be related in these complicated things?

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GiveMeABreak
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Re: C5 Steering

Post by GiveMeABreak » 14 Nov 2018, 09:39

Well that is the first problem, the ESP fault has got absolutely nothing to do with break wear wires

The ESP system will bring up a fault for a multitude of errors one of which, will be related to the steering wheel angle sensor. This very likely needs to be re-calibrated as a result of doing the rack if it’s become out of kilter. This is another reason why you need a lexia system as it can only be done following the procedure in there.

To be honest, you could still have a number of faults which may not be detected by the generic code reader. But if the steering wheel angle sensor is not corrected, then your ESP system will going to back up mode, and this will mean No ABS system, and if you have the electronic parking brake, you will lose all the automatic functions like Hill start assist etc,

Until you get the system diagnosed properly you’re going to have to expect problems like this.