C5 X7 Suspension faulty V-max 90km/h

adi-xon · Post by **adi-xon** » 04 Oct 2020, 16:52

Hi everyone,

I have small or big problem with my Citroen C5. I have error suspension faulty v-max 90km/h and whole car went down. Not possible to get this to any other level.
I've check with Diagbox and have C1146 - Rear height corrector faulty. Can someone advice how to diagnose whats the problem and how to check the rear corrector if its faulty or not?
I've checked initially all fuses related to Hydractive. In BFH1 G39 - 10A is fine, there is empty field in MF7 fuse and seems its have to be like this, huge fuse 40A behind the battery is also fine
I've checked connection to the height corrector. cleaned the connection. Corrector sting is fine as I've replaced it 2 months ago.
The LDS LHM Pump doesn't start and the question is how the car is behaving if the rear corrector is faulty at all? It is working as design that whole suspension doesnt work and LDS pump doesn;t start?
How to check with DiagBox or with multimeter check if the rear corrector is faulty?

Best regards,
Adrian

Post by **GiveMeABreak** » 04 Oct 2020, 16:58

That code is indeed related to the height sensor. When the height sensors are faulty or not supplying data, then no height correction will take place.

Did you say you have already replaced the rear height sensor? If so was it a new one or second hand?

Diagbox will provide some tests for the suspension if you go into the parameters section of the suspension ECU so you can see what is happening when you try to change heights.

adi-xon · Post by **adi-xon** » 04 Oct 2020, 17:45

Hi Marc,

Yes rear height sensor and error from DB C1146 is related to it. I've didnt replaced sensor but the string which is a part of it.
So in this particular case you mean if its rear sensor is faulty then even Hydractive pump will be not starting ? Or the front of the suspension should work and rear not?
Can you advice how can I check it to avoid that the suspension go down at all and confirm that the rear sensor is faulty before replacement? Because till now Im able to drive slowly

Hell Razor5543 · Post by **Hell Razor5543** » 04 Oct 2020, 17:57

As the suspension is electronically controlled, if a sensor fails so that the relevant ECU cannot 'see' what it is 'reading' the system will not operate for safety reasons. Suppose, for example, the suspension was at maximum height and the pump remained running? It could overstress pipework and cause one or more to fail. It is far safer for the system to fail-safe off.

Post by **GiveMeABreak** » 04 Oct 2020, 18:13

adi-xon wrote: ↑04 Oct 2020, 17:45 Hi Marc,

Yes rear height sensor and error from DB C1146 is related to it. I've didnt replaced sensor but the string which is a part of it.
So in this particular case you mean if its rear sensor is faulty then even Hydractive pump will be not starting ? Or the front of the suspension should work and rear not?
Can you advice how can I check it to avoid that the suspension go down at all and confirm that the rear sensor is faulty before replacement? Because till now Im able to drive slowly

I'm not sure what you mean by 'string'?

But if any of the height sensors are malfunctioning, then it will prevent any height correction from taking place.

The height sensors can wear out internally (potentiometer tracks) and they need replacing. I've had both mine replaced when I had the same error and warning. The first I knew of it was when I had a directional headlight fault (for which the height sensors also supply information to) with the max. speed warning. The car would intermittently react to the height control button, sometimes lowering or raising, other times nothing, so not a good idea to play with the height control as you could end up stuck in the low position.

I had both sensors replaced under warranty and the problem was resolved.

adi-xon · Post by **adi-xon** » 04 Oct 2020, 18:30

By string I mean this element below.

Alright so I will get a new sensor and will replace it. Any action is needed from DiagBox after the replacement or its enought to plug and play ofcourse disconnecting the battery before?

Once I've got this done I will share the results.
Thanks for help

Hell Razor5543 · Post by **Hell Razor5543** » 04 Oct 2020, 18:36

That is commonly know as a 'dog bone', due to its' shape.

Post by **GiveMeABreak** » 04 Oct 2020, 22:22

adi-xon wrote: ↑04 Oct 2020, 18:30 By string I mean this element below.

Alright so I will get a new sensor and will replace it. Any action is needed from DiagBox after the replacement or its enought to plug and play ofcourse disconnecting the battery before?
Once I've got this done I will share the results.
Thanks for help

Ok the link rod.

Just make sure when you are replacing it, that you have the vehicle supported independently and don't get under the car unless it has independent support - as it can collapse without warning.

Make sure you don't remove the clamp on the axle or move it, otherwise your height settings will all be out.

You don't need to code it or tell the ECU you have replaced them - they do not have an independent ECU inside the height corrector units- they just send out analogue signals to the suspension ECU.

Post by **Paul-R** » 04 Oct 2020, 23:12

adi-xon wrote: ↑04 Oct 2020, 18:30By string I mean this element below.

There was a photograph of the link earlier today but now it's disappeared. Is this a forum problem? Has there been an update of the software?

Post by **GiveMeABreak** » 04 Oct 2020, 23:22

No, it was me by accident.

I went to quote a post and edited the original instead of a quote by accident. I didn’t want to reproduce the large photo in my quote so deleted it.

I’ve now put a similar picture in its place.

adi-xon · Post by **adi-xon** » 05 Oct 2020, 16:25

Hi all,

So the solution was the replacement of the 40A fuse on the right side of the battery. I missed that one unfortunately. I've seen several posts related to this fuse issue and most anytime there were two errors coming in DB for the rear and front height sensor. Not a single for a rear only. But doesnt matter. Most important that its working fine. Anyway I found some info's if this fuse will break once again then LDS LHM pump might require adjustment/replacement.

Best regards,
Adrian

Hell Razor5543 · Post by **Hell Razor5543** » 05 Oct 2020, 16:28

Well done, and thanks for letting us know. Here's hoping that the fuse just failed from old age, and not for an active reason.

Post by **xantia_v6** » 05 Oct 2020, 19:35

adi-xon wrote: ↑05 Oct 2020, 16:25 Hi all,

So the solution was the replacement of the 40A fuse on the right side of the battery. I missed that one unfortunately. I've seen several posts related to this fuse issue and most anytime there were two errors coming in DB for the rear and front height sensor. Not a single for a rear only. But doesnt matter. Most important that its working fine. Anyway I found some info's if this fuse will break once again then LDS LHM pump might require adjustment/replacement.

Best regards,
Adrian

There are several topics on this forum about the suspension pump and blown fuses. For example, see: viewtopic.php?t=60565

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C5 X7 Suspension faulty V-max 90km/h

C5 X7 Suspension faulty V-max 90km/h

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Re: C5 X7 Suspension faulty V-max 90km/h

Re: C5 X7 Suspension faulty V-max 90km/h

Re: C5 X7 Suspension faulty V-max 90km/h

Re: C5 X7 Suspension faulty V-max 90km/h

Re: C5 X7 Suspension faulty V-max 90km/h

Re: C5 X7 Suspension faulty V-max 90km/h

Re: C5 X7 Suspension faulty V-max 90km/h

Re: C5 X7 Suspension faulty V-max 90km/h

Re: C5 X7 Suspension faulty V-max 90km/h

Re: C5 X7 Suspension faulty V-max 90km/h

Re: C5 X7 Suspension faulty V-max 90km/h