C5 Mk3 X7 Autobox Interlock Relay

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milleplod
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Re: C5 Mk3 X7 Autobox Interlock Relay

Post by milleplod » 21 May 2018, 16:40

No real need for special tools, mine came out easily with the use of an old AA membership card! Just slip it between the trim and centre console at one side or the other nearest to the gearstick end - a bit of leverage with the plastic card and the trim will just pop up. The only difficulty I had was that the gearlever just wouldn't come apart from the shaft, but I managed without doing it, I was scared of breaking something!

Pete

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Re: C5 Mk3 X7 Autobox Interlock Relay

Post by milleplod » 21 May 2018, 18:53

Video of how easy it is here -

Pete
Last edited by myglaren on 21 May 2018, 21:03, edited 1 time in total.
Reason: YouuTube link

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Re: C5 Mk3 X7 Autobox Interlock Relay

Post by petef » 22 May 2018, 16:23

I have managed to remove the bezel using a credit card sized piece of plastic. The video shows everything springing out easily. In practice, for me, the gear lever top stayed firmly in place on the shaft - perhaps there is a knack to remove this>?
Any way I have sprayed silicone lubricant around the release mechanism, we will see if the interlock now behaves reliably. If not it will mean finding and replacing the relay - was a part number for that ever identified?

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Re: C5 Mk3 X7 Autobox Interlock Relay

Post by petef » 23 May 2018, 11:03

If no part number is known perhaps someone - EDC5? - could tell me the colour of the relay. I might be able to trace it from that.

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Re: C5 Mk3 X7 Autobox Interlock Relay

Post by GiveMeABreak » 23 May 2018, 11:22

Pete I don't have your VIN, so this is based on an early X7 Auto with DW10BTED4 engine - should be the same. Now you know the location, you should be able to identify the connector to the correct relay.

Click to Zoom
X7 AM6 Shift Lock Relay.png
  • 1642 is the gear lever blocking actuator control relay
Note: It is connected to a 10 pin black connector
  • 1603 is the assembly (automatic gearbox control)
10PR.PNG
10PR.PNG (15.51 KiB) Viewed 213 times
10PR is the main harness which goes into the glovebox area

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Re: C5 Mk3 X7 Autobox Interlock Relay

Post by petef » 23 May 2018, 11:44

Thanks Marc. Very useful. The item 1642 is clearly the bit I'm after but is not the part number - seems to be the wiring harness reference number. Just looking at it it would appear to be a pretty standard 4 pin relay. But my old - and possibly incomplete - Citroen Service doesn't show anything. Could you give me the part number? My VIN is VF7**************[VIN obfuscated, can be read by forum staff].

Thanks

Peter

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Re: C5 Mk3 X7 Autobox Interlock Relay

Post by EDC5 » 23 May 2018, 12:33

It's a generic SPST 4 terminal relay. I don't remember the part number off the top of my head but it's installed in a block with a couple of other identical ones.

He only way I could trace it was with someone pressing and releasing the brake pedal as I listened for the click and eventually removed the offending relay.

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Re: C5 Mk3 X7 Autobox Interlock Relay

Post by GiveMeABreak » 23 May 2018, 12:57

I think it's a pretty standard relay - there are no part numbers that I can see apart from the buzzer and flasher unit relays - so best to remove it and id it, or see if Elis can remember where he got his - but I would suggest you replace it with the same power ratings.

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Re: C5 Mk3 X7 Autobox Interlock Relay

Post by EDC5 » 23 May 2018, 13:07

Actually, I now think it was a 5 pin relay, very similar if not identical to this:

Image

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Re: C5 Mk3 X7 Autobox Interlock Relay

Post by petef » 23 May 2018, 15:22

Thanks guys.
Looking at the diagram showing relay 1642 it does seem to have 5 terminals - just that one is not used.
I am now limbering up for the contortions required to get to it. Does the glove box have to come out or can you get to it from underneath?

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Re: C5 Mk3 X7 Autobox Interlock Relay

Post by EDC5 » 23 May 2018, 15:46

Yep, there is a high current 25 amp NC contact and 10 amp NO contact on that 5 pin relay.

Don't take the glove box out, its a swine to refit properly (including the cool air feed).

Just take off the panel under the glove box, two twist clips I think at the front and maybe the side of the centre console that goes into the foot well (T20 bit required).
Then at the very back left hand side of the foot well (when looking towards the front of the car) look up from there and you should see some plastic bracket holding a couple of relays.

I wish I’d taken some pictures at the time but it didn’t occur to me.

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Re: C5 Mk3 X7 Autobox Interlock Relay

Post by petef » 23 May 2018, 16:27

So...... panel removed under glove box. Found bracket holding just one green relay at back LHS ( and 5 unterminated wires bound together - perhaps for another relay for goodies not fitted on my car). However when I removed it the interlock still works - intermittently as before - so it can't be the one. Couldn't feel it clicking when my wife operated the brakes either and the pin configuration is not the same as the pic above . Have a feeling the one I need must be nearer the central console - but where?

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Re: C5 Mk3 X7 Autobox Interlock Relay

Post by EDC5 » 23 May 2018, 17:55

petef wrote:
23 May 2018, 16:27
So...... panel removed under glove box. Found bracket holding just one green relay at back LHS ( and 5 unterminated wires bound together - perhaps for another relay for goodies not fitted on my car). However when I removed it the interlock still works - intermittently as before - so it can't be the one. Couldn't feel it clicking when my wife operated the brakes either and the pin configuration is not the same as the pic above . Have a feeling the one I need must be nearer the central console - but where?


When I press my brake pedal I hear the interlock under the gear stick click as well as the relay click under the glovebox.

That was the only way I could find it.

From memory it was a long way up behind the glovebox, I'd try and see if there is another bracket even further up behind the BSI area.

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Re: C5 Mk3 X7 Autobox Interlock Relay

Post by petef » 23 May 2018, 19:47

Yes I can hear it clicking too and certainly seems to be behind LHS rear of glove box.
Even had mirrors involved (no smoke though) and still couldn't see it. Will have another look tomorrow when neck has recovered a bit!

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Re: C5 Mk3 X7 Autobox Interlock Relay

Post by EDC5 » 23 May 2018, 20:11

petef wrote:
23 May 2018, 19:47
Yes I can hear it clicking too and certainly seems to be behind LHS rear of glove box.
Even had mirrors involved (no smoke though) and still couldn't see it. Will have another look tomorrow when neck has recovered a bit!


I'm glad you can hear it, and I hope when you find it, it is indeed the source of the problem.

As I said in a previous post I had to be practically upside down in the bottom of the footwell to even get close to it :shock: