Electronic anti-theft faulty error on C4 (2005)

[Rob_E]

Yesterday I got in the car to go out and when I turned on the ignition I got an error "Electronic anti-theft faulty" pop up on the display, and the car would not start, the engine did turn over but I assume the immobiliser was still active as a result of the fault and so was preventing it starting.

A bit of googling suggested that sometimes the chip in the key could fail, but unfortunately I didn't have the spare with me to try another one.

I went back out to it about an hour later, annoyingly after it was too late to get where I was originally going, and it then started accepting the key and would start as normal.

My initial thought was maybe the key was failing, based on what I had found from googling, so went to fetch the spare key. So the car started again, and also further times once I had picked up the key and after stopping for diesel on the way home. When I got back last night it was still accepting the remote key that I normally use, and also the spare (non remote) key.

This lunch time I again went to go out somewhere and it was again refusing to accept the key, popping up the warning message on the display; the same with the spare key as well. So it's starting to look like the problem is the car rather than the keys, I think.

As was the case yesterday, I went back out half an hour to an hour later and it all seemed fine again.

I've plugged in Lexia, even though at that point it was accepting both the keys, and I can see 4 occurrences of the following fault:
Fault (FC83) : Transponder aerial
then in the detail it has a slightly different code:

• Family: Top of column

• Fault code: 0C83

• occurrences: 4

• Local/Remote: Local

This is quite an annoying intermittent fault, as I never know when I go to the car now if I'm going to be able to use it or not. I'm not sure what triggers it to start working again, as nothing seems to have changed in between as the car has just been parked in the same place. Likewise why it stops recognizing the keys as it hadn't moved since it was working the previous night.

Anyone else experienced similar, do the transponder aerials often fail or is this more likely some sort of wiring issue
I assume the aerial is in the steering column close to or around the ignition key barrel?

I was hoping that having the spare key would provide a work around, but when the issue happens it seems to affect both, so I'm a bit stuck when it does occur and slightly concerned I'll get stranded at the destination even if it does for once work at the point I need to go somewhere.

In case the systems work differently, it is a 2005 2.0 HDI.

Thanks in advance
Rob

[wheeler]

The aerials failing is not as common as it was on earlier models like Saxo’s &. Xantias but not unheard of. Id just replace it it were me to rule it out. They are fairly cheap brand new & don’t require any programming. Once you remove the column cowlings its just clipped over the ignition barrel & unplugs from the comms unit.

[Rob_E]

Just phoned the dealer, and you're right, they said it is £12.43 for a new one so I've ordered one as it is worth a try if it solves the problem quickly. The guy on the phone seemed to think it might need programming to the car in some way, though did admit he wasn't a mechanic; but from everything I've read on here it sounded like the only programming was the keys to the BSI when replacing them with new ones, so hopefully it will be a simple swap.

[wheeler]

100% no programming on this vehicle. 5 minute job.

[Adelaide mubaya22]

How do you do the work. Pliz help I have the same problem

[wheeler]

Probably best to start a new topic about your specific car with a bit more detail about your specific problem.