C5 2010 hydoractive front heigth sensor failure

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Greg2791
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C5 2010 hydoractive front heigth sensor failure

Post by Greg2791 »

Hi,
Finally - after 12 years I got a failure of my suspension system, I was on the trip but fortunately back home over 150km with faulty suspension - the car did not fall down.
I checked the fuses - all good, no sign of anything around , nothing being burnt (plastics) nor any corrosion.
I checked the voltage on he pump - nothing there (thick wires going to the device underneath the LDS oil container.
The pump is not running at all, after couple of kilometers it shows typical alarm for suspension issues - 'Suspension fault 90km/h'. Next - I asked my mechanic to check computer Following faults appeared:
C1141 - Front Body Height Sensor Fault and some other but he said they could be ignored or caused by the critical fault:
U1118, U2118,U2005.
I still haven seen the sensor mount. As now - car is fully down, I will check the cables and sensor itself tomorrow.

Any advice? I think I have to buy a new sensor. Is the sensor the same as per Peugot and C5 without hydroactive suspension?

I went through the instruction how to calibrate it, and wondering if this can be done even roughly without the Citroen tools , just to allow my car to drive to the garage that have the tools and know how to do it.
See the reading from the sensors, In fact he first row looks different. I am wondering if I can use this tool to setup the suspension after the sensor replacement. We were trying to energize raising the front - nothing happened.
I think it because of faulty sensor so the computer does not allow to control it.
IMG_20220530_181803.jpg
Greg
Greg2791
Donor 2022
Posts: 13
Joined: 05 Jan 2019, 19:16
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Re: C5 2010 hydoractive front heigth sensor failure

Post by Greg2791 »

Day2:
I took out the sensor, not easy job. It appears to be fine. 90deg working range 0.3V to 4.2V outputs tested on the second plug (not the sensor one). It is unlikely that the wire to the suspension control unit is broken, My next step is to check the relay 1524, I have following questions:

Do you know where can I find it (1524) ?

Is this relay 'always' energized?

For me it looks like it should be 'always' on (Z13 signal from fuse box ). As far as I remember there was no 12V going to the pump when car was on I have tore-test it more carefully. I had no drawing yesterday and I focused on the sensor too much.
Attachments
Front Height Sensor.jpg
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GiveMeABreak
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Re: C5 2010 hydoractive front heigth sensor failure

Post by GiveMeABreak »

The height correctors themselves are simple analogue potentiometers on tracks. I can't see that the relay has anything to do with their operation as if the relay was not working then the pump would not be operational.

I would focus on connections from the front height sensor to the suspension ECU within the BHI. If LDS has gotten in or a pin is not making contact, then this can upset the data received.

The relay 1524 is supplied from the BFDB battery fusebox (wire B7740). The relay then supplies the pump motor block (B7739).

Wire Z13 is the control wire to the BSI (Fused with F13) and the engine fusebox.

The suspension circuit is triggered on wake up of the RCD circuit (unlocking of doors for example), which readies the system. Height correction then starts at this time, which is likely what the control wire from the BSI does.

Sensor
7702 is the front height sensor

Wires:
Pin 1: 7726 : Front body height sensor + power supply
Pin 2: 6604A : front body height sensor signal
Pin 3: 7727 : Front body height sensor - power supply

Image


As for the location of the relay. It is in area 'H' shown below and detailed a little better in the mini diagram 'H'

Image
Greg2791
Donor 2022
Posts: 13
Joined: 05 Jan 2019, 19:16
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Re: C5 2010 hydoractive front heigth sensor failure

Post by Greg2791 »

It was F01, I could not find the relay 1524 - it is shown on 2 diagrams E & H.
To put back the front height sensor
I had to cut out a piece of its bracket that holds the connector. It was then possible to mount it back.
thanks for help and the drawings . It was very helpful to narrow the searching.
It is much easier
- to disconnect and connect again the small push in arm to the clamp rather thane the sensor.
- to take out the bracket and mount the sensor outside then attach the arm and put the bracket in its place.
Attachments
Fuse F01.jpg
FHS_bracket.jpg