Engine immobiliser fault

Talk about the 406's electrical system, what wires do what, how to add extra functionality, etc.

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Kekkee
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Joined: Mon Feb 14, 2022 1:47 pm

Engine immobiliser fault

Post by Kekkee »

Hello everyone!

I am new here but I was thinking that you guys might help me. I have a 2003 406 2.0 HDi that runs great but last week this immobiliser fault error showed up and the car won't start(on ignition wipers and headlights start working and the little key light is on). I have read some of the topics with the same title and tried some things but the problem is still there. On day 1,2 and 3, after reconnecting the battery, leaving it disconnected over night, resetting the BSI, checking if the floor is wet, taking out the SH fuse, disconnecting and reconnecting using contact spray all the connectors I could find under the steering wheel, at the ECU and at the fuse box, it didn't start, but on day 4 I went to try again, the remote unlock didn't work so I thought "no chance" but it actually worked from the first try. I thought the problem was solved but after 3 days of driving the car every day, the error is back.

Did anyone actually solve this problem? Can anyone help?
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Doggy
Mod with a 2.2 HDi, De-Fapped!
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Joined: Mon Oct 13, 2008 11:49 pm
Location: Northants

Re: Engine immobiliser fault

Post by Doggy »

I've not owned a 406 for a few years, so take this with a pinch of salt......

I think you shouldn't be seeing the key symbol normally and the fact that you are indicates the car is not 'seeing' the transponder chip in the key.
(You may be able to prove this by opening the driver's door with the key in the ignition lock. IF I remember right, you should normally hear a chime to remind you to remove the key. If this is now not happening it would confirm failure to read the transponder.

The transponder chip is read by a balck plastic tubular device that partially surrounds the lock barrel. These have been know to move and then fail to work. If this sounds like your problem, remove the steering column shroud and check.
2002 HDi 2.2 Exec Estate, (2008-12) (wonderful)
2003 HDi 2.2 6-speed Exec Estate (2012-19) (also a gem)
2009 Citroen C5 2.0 HDi VTR+ Estate (godawful heap)
2008 BMW E91 330i touring (great fun - murdered by a reversing SUV)
2007 BMW E91 325i touring (slower smoother quieter)
Kekkee
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Re: Engine immobiliser fault

Post by Kekkee »

Thank you so much for responding. I went to check if this is the case, apparently it is. There's no "key reminder" sound. I will open the shroud and check.
Kekkee
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Re: Engine immobiliser fault

Post by Kekkee »

Is this the part you are talking about? I took it out, put it back in and tightened a loose screw but no luck. do you think it could be broken?

https://ibb.co/NK7zHFy
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Doggy
Mod with a 2.2 HDi, De-Fapped!
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Joined: Mon Oct 13, 2008 11:49 pm
Location: Northants

Re: Engine immobiliser fault

Post by Doggy »

I really don't want to mislead you here, I'm working from recollection of 406 behaviour and it's about 3 years since I was in one. I think mine used to chime if you opened the door without taking the key out of the ignition, but I can't remember for certain. If you're sure yours used to do this and now doesn't we're on the right track.

Hopefully someone that still has a 406 can confirm, (or otherwise), please?


Yes, that's the beast in your picture, (called the 'aerial' part no. 6160 77). It should be looking for the transponder chip inside your key, I've seen them described as 'ID46', ' PCF7936', or both. Looks like :

Image

I understand these need to be programmed to suit the car, (they are one-time programmable). It may be simple to do this with the PP2000 diagnostic kit, but I've never done it personally. There are some posts somewhere on the site from quite a few years ago, I'll try to find them and post the links for you.

Aerials are interchangeable between similar cars - the programming is restricted to the ID46 chip and the matching code(s) stored in your car's BSI. Therefore if the aerial is dead, a new part or one from a breaker should be a direct swap. If it's the chip, you need a new one and it coding to the car.

I vaguely remember someone taking the ID46 chip out of their key and taping it on near the aerial, (think this was to allow a different key/lock barrel to work with their car). Meant the imobiliser was effectively disabled, but nobody would know except you. Could be worth a try - maybe yours will work if the chip & aerial are closer to each other.

This link may help: https://www.406oc.co.uk/viewtopic.php?f ... 46#p227214
2002 HDi 2.2 Exec Estate, (2008-12) (wonderful)
2003 HDi 2.2 6-speed Exec Estate (2012-19) (also a gem)
2009 Citroen C5 2.0 HDi VTR+ Estate (godawful heap)
2008 BMW E91 330i touring (great fun - murdered by a reversing SUV)
2007 BMW E91 325i touring (slower smoother quieter)
arber333
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Posts: 75
Joined: Wed May 09, 2018 10:02 am

Re: Engine immobiliser fault

Post by arber333 »

Doggy wrote: Mon Feb 14, 2022 9:55 pm I vaguely remember someone taking the ID46 chip out of their key and taping it on near the aerial, (think this was to allow a different key/lock barrel to work with their car). Meant the imobiliser was effectively disabled, but nobody would know except you. Could be worth a try - maybe yours will work if the chip & aerial are closer to each other.
In my EV conversion i came across immobiliser function, but i quickly overcame it by providing 12V to alternator (BSI) "engine running" pin. It seems that when this step is achieved BSI stops requesting immobiliser data.
Just saying immobiliser can be circumvented untill you get new chip or aerial...
arber333
1.8 16v
Posts: 75
Joined: Wed May 09, 2018 10:02 am

Re: Engine immobiliser fault

Post by arber333 »

Here is my post on "engine running" wire from couple of years back...
https://www.406oc.co.uk/viewtopic.php?p=252683#p252683
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