C5 won't start - reset immobiliser?

melpg · Unread post by **melpg** » 23 Mar 2010, 22:53

Hi, I've searched back 40 pages to see if my problem has been mentioned before but decided it was time to register and post it myself!

My C5 won't start. I came home from work, went to move the car later and it will not start. When the ignition is on the wipers run intermittently and the sidelights come on. The remote locking won't work now either.

When my OH had the car a couple of years ago the same thing happened. The car was taken to the dealers and the fault was due to the air con fuse. They replaced the fuse and reset the immobiliser. (I don't pretend to know why this would cause the immobiliser to lock on)

It then happened a second time and this time my OH replaced the fuse and a mechanic friend told him how to reset the immobiliser.

I did have the air con on earlier today and turned it off when I was on my way home but we have checked the fuses and they're fine so not sure if this is why the immobiliser has become fixed on or not.

The trouble is we cannot remember the way to reset the immobiliser. Tried disconnecting the battery but that didn't work.

We seem to recall something about putting the key in the door and locking and unlocking 3 times but this didn't work either. There's probably more to it than that of course or maybe you have to stand on one leg and touch your nose at the same time??!!

If it works I'll try it

Please help if you have any ideas, cheers.

Citroenmad · Unread post by **Citroenmad** » 23 Mar 2010, 23:00

You could try disconnecting the battery and leaving it off a short time. This might reset the codes.

melpg · Unread post by **melpg** » 23 Mar 2010, 23:07

Will give it a try, maybe we didn't leave it off long enough.

Thanks

nginmu · Unread post by **nginmu** » 24 Mar 2010, 02:13

Just been reading the haynes book of fault codes, citroen section. it mentions disconnecting battery negative for two full minutes.. try it & see..?

It also seems to say that newer / EOBD vehicles do require an actual fault code reader device to be plugged in, to reset codes.

melpg · Unread post by **melpg** » 24 Mar 2010, 10:37

Gave it a go but no luck I'm afraid.

OH spoke to dealer who suggested charging battery so on with that at mo but he did tell him how to reset the immobiliser for anyone else with same problem -

Put key in ignition, hold lock button for 5-10 seconds then lock car and leave as long as you can so it resets itself (hopefully)

Ed Armstrong · Unread post by **Ed Armstrong** » 25 Mar 2010, 20:14

Don't know if this will clear it but was told to put key in ignition and turn to full on position - do this 10 times then start engine.
Ed

melpg · Unread post by **melpg** » 26 Mar 2010, 13:07

Thanks but we didn't get that far in the end!

It WAS the air con fuse although it didn't look like it had blown. Paid a man with a computer £80 to come out and he replaced the fuse then had to recode all the keys to get the immobiliser off. Still cheaper than getting it transported to Citroen mind. He didn't know why it had caused the immobiliser to come on though, said they're just temperamental.

Oh and while the battery was being charged inside, we left the key in the ignition and locked the drivers door while we popped out for half an hour. 4 different passers by called the police who were waiting for us when we came back. The policeman had realised the passenger door wasn't locked, tried to lock it and got the key stuck. So after pulling with pliers then molgrips it eventually came out but came off from the fob at the same time.

It never rains........

ibog · Unread post by **ibog** » 20 Apr 2023, 12:42

I was just wondering if we are all cursed..

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C5 won't start - reset immobiliser?

C5 won't start - reset immobiliser?

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