Underseat lights C5 X7

This is the Forum for all your Citroen Technical Questions, Problems or Advice.

Moderator: RichardW

User avatar
xf1ref
Posts: 139
Joined: 20 Feb 2012, 06:42
x 4

Underseat lights C5 X7

Post by xf1ref » 04 Jul 2018, 09:20

Hello everyone!

I'd like to mount on my car the rear passenger foot lights. I found to buy the lamps but the problem is that I don't have a diagram to see where the lamps are connected. I suppose that are connected in the connector under the seat.
There is any chance to find an electric diagram for these lights?
VIN: VF7**************[VIN obfuscated, can be read by forum staff]********
Last edited by GiveMeABreak on 05 Jul 2018, 09:35, edited 1 time in total.
Reason: VIN Masked

User avatar
GiveMeABreak
Forum Admin Team
Posts: 11106
Joined: 15 Sep 2015, 19:38
x 940

Re: Underseat lights C5 X7

Post by GiveMeABreak » 04 Jul 2018, 10:13

I'll have a look for you in a second :-D

User avatar
GiveMeABreak
Forum Admin Team
Posts: 11106
Joined: 15 Sep 2015, 19:38
x 940

Re: Underseat lights C5 X7

Post by GiveMeABreak » 04 Jul 2018, 10:49

Ok, so I've just cut out the relevant extract and written the key for the relevant components for you.

3038 & 3039 are the underseat lamps and they share the same earth as 3072, (the font RH door lamp). The power is supplied via 6338, the Seat Position Memory ECU.

Click to Zoom Diagram
X1Ref Seal Lamp Wiring.PNG
6338: Seat position memory ECU
3038: Rear RH footwell lighting[/color]
3039: Left-hand rear footwell lamp
3043: Rear LH interior door opening control lamp
3044: Rear right interior door opening control light
3048: Driver's interior door opening control light
3072: Front LH door lamp
3073: Front RH door lamp
6036: Driver's door electric window/mirror control pad
6338: Seat position memory ECU
6404: Passenger´s rear view mirror memorisation and lighting control unit
6212: Rear left-hand door lock assembly
6217: Rear right-hand door lock assembly
Let me know if you need anything else :wink:

User avatar
xf1ref
Posts: 139
Joined: 20 Feb 2012, 06:42
x 4

Re: Underseat lights C5 X7

Post by xf1ref » 04 Jul 2018, 12:44

Great!
Thanks a lot, Marc!

User avatar
xf1ref
Posts: 139
Joined: 20 Feb 2012, 06:42
x 4

Re: Underseat lights C5 X7

Post by xf1ref » 05 Jul 2018, 09:18

I tried yesterday to remove the seat position memory Ecu from under the seat but without success. I think I have to remove the hole seat from the car to have access to Ecu.
I saw that seat Ecu has three connectors and each one connector has the pins numbered by column (A,B,C) and row (from 1 to 9).
In the diagram is indicated pin A7 but all three connector have a A7 pin.
Marc, could you tell me what is 3006? maybe is the connector code.

User avatar
GiveMeABreak
Forum Admin Team
Posts: 11106
Joined: 15 Sep 2015, 19:38
x 940

Re: Underseat lights C5 X7

Post by GiveMeABreak » 05 Jul 2018, 09:22

Ok let me fire up the HAL9000💻

User avatar
xantia_v6
Forum Admin Team
Posts: 5702
Joined: 09 Nov 2005, 23:03
x 232

Re: Underseat lights C5 X7

Post by xantia_v6 » 05 Jul 2018, 09:31

According to the diagram above, it is a brown connector, is there more than one of them?

User avatar
GiveMeABreak
Forum Admin Team
Posts: 11106
Joined: 15 Sep 2015, 19:38
x 940

Re: Underseat lights C5 X7

Post by GiveMeABreak » 05 Jul 2018, 10:14

xf1ref wrote:
05 Jul 2018, 09:18
I tried yesterday to remove the seat position memory Ecu from under the seat but without success. I think I have to remove the hole seat from the car to have access to Ecu.
I saw that seat Ecu has three connectors and each one connector has the pins numbered by column (A,B,C) and row (from 1 to 9).
In the diagram is indicated pin A7 but all three connector have a A7 pin.
Marc, could you tell me what is 3006? maybe is the connector code.


Ok, so 3006 is the Rear footwell lights supply (BSI).
B831A & B831B are battery + supply wires (any wire with the first letter 'B' is Battery +)

The Seat Position Memory ECU (6338) uses the CAN High (9025) & CAN Low (9024) networks to control various functions.

You have to remember that the diagrams are all separate and only show the relevant connections for the parts under query and for the fitted options. The ECU socket for this relevant diagram is a 24 pin Brown using the pin A7 as you say - but remember this diagram is specifically for the lighting aspects.

Here is another diagram for comparison of the Driver's Electric Seat - here you can see the other connections on the unit, but the pin assignments are labelled differently, with different connections because I had to specify these to get this diagram up.

The others shown here are a 24 Pin Grey and 24 pin Black socket. They control the electric seat functionality for passenger and driver. They may also connect the control and power for the massaging function (for the full leather seats only) and the heated seats, plus of course the AFIL (Lane Wandering) system chair vibrators (again if fitted as an option). Those components have different wiring diagrams too.
X1REF Seal Lamp Wiring B.PNG
6338 ECU Showing Electric Seat Connections
So basically regarding the rear lighting, there will be the battery + supply, common earth and then the CAN network also switching these on and off and controlling them.

Unfortunately the PIN assignments are not always the same as options change on the vehicles and there isn't one complete diagram showing everything with every option - only the component parts. :-D

I would go and have a look at mine, but the car is loaded up with parts to assemble a 3 seater garden bench on Saturday, so all the seats are folded down! :-D

User avatar
GiveMeABreak
Forum Admin Team
Posts: 11106
Joined: 15 Sep 2015, 19:38
x 940

Re: Underseat lights C5 X7

Post by GiveMeABreak » 05 Jul 2018, 10:19

xantia_v6 wrote:
05 Jul 2018, 09:31
According to the diagram above, it is a brown connector, is there more than one of them?
Yes - another 2 at least - but only shown when looking at a specific area Mike as you probably know. I have dug up another one above for the electric seat part.

User avatar
xf1ref
Posts: 139
Joined: 20 Feb 2012, 06:42
x 4

Re: Underseat lights C5 X7

Post by xf1ref » 05 Jul 2018, 11:14

GiveMeABreak wrote:
05 Jul 2018, 10:14
xf1ref wrote:
05 Jul 2018, 09:18
I tried yesterday to remove the seat position memory Ecu from under the seat but without success. I think I have to remove the hole seat from the car to have access to Ecu.
I saw that seat Ecu has three connectors and each one connector has the pins numbered by column (A,B,C) and row (from 1 to 9).
In the diagram is indicated pin A7 but all three connector have a A7 pin.
Marc, could you tell me what is 3006? maybe is the connector code.


Ok, so 3006 is the Rear footwell lights supply (BSI).
B831A & B831B are battery + supply wires (any wire with the first letter 'B' is Battery +)

The Seat Position Memory ECU (6338) uses the CAN High (9025) & CAN Low (9024) networks to control various functions.

You have to remember that the diagrams are all separate and only show the relevant connections for the parts under query and for the fitted options. The ECU socket for this relevant diagram is a 24 pin Brown using the pin A7 as you say - but remember this diagram is specifically for the lighting aspects.

Here is another diagram for comparison of the Driver's Electric Seat - here you can see the other connections on the unit, but the pin assignments are labelled differently, with different connections because I had to specify these to get this diagram up.

The others shown here are a 24 Pin Grey and 24 pin Black socket. They control the electric seat functionality for passenger and driver. They may also connect the control and power for the massaging function (for the full leather seats only) and the heated seats, plus of course the AFIL (Lane Wandering) system chair vibrators (again if fitted as an option). Those components have different wiring diagrams too.
X1REF Seal Lamp Wiring B.PNG
6338 ECU Showing Electric Seat Connections
So basically regarding the rear lighting, there will be the battery + supply, common earth and then the CAN network also switching these on and off and controlling them.

Unfortunately the PIN assignments are not always the same as options change on the vehicles and there isn't one complete diagram showing everything with every option - only the component parts. :-D

I would go and have a look at mine, but the car is loaded up with parts to assemble a 3 seater garden bench on Saturday, so all the seats are folded down! :-D

Image


Thanks, the information is very useful. There are three connectors on seat ECU and only one is brown. I will have a look these days at a friend C5 but his car has more options (massaging and Lane Wandering) and how you said, it's possible to have a different PIN assignments.
Last edited by xf1ref on 05 Jul 2018, 14:06, edited 1 time in total.

User avatar
GiveMeABreak
Forum Admin Team
Posts: 11106
Joined: 15 Sep 2015, 19:38
x 940

Re: Underseat lights C5 X7

Post by GiveMeABreak » 05 Jul 2018, 11:22

I changed the under seat bulbs in mine for some coloured LEDS to match the other ones, and I remember that the lights were all tightly clipped up there - so not very easy to see the wiring unfortunately - and most of the components are in the seat itself! Number 8 is the seat ECU.
X7 Seat and Lighting Memory units C.PNG

User avatar
xf1ref
Posts: 139
Joined: 20 Feb 2012, 06:42
x 4

Re: Underseat lights C5 X7

Post by xf1ref » 06 Jul 2018, 12:15

Today I removed the seat to have access to ecu and I finally extracted it. I solder a wire from Ecu pin A7 for supply + and for negative from pin B1. B1 and C1 are the negative for seat ecu.
I have tested with a w5w bulb and It's working! =D>
Attachments
20180706_123652[1].jpg
20180706_122812[1].jpg
20180706_112455[1].jpg

User avatar
EDC5
donor 2018
Posts: 1029
Joined: 01 Jul 2017, 21:48
x 76

Re: Underseat lights C5 X7

Post by EDC5 » 06 Jul 2018, 12:47

Excellent!

I've always wanted to look inside of the under seat ECU so thanks for supplying pics.

I've wanted to replace the relays on the board with MOSFETs too as the clicking is annoying when moving the seats.