Jump to content

Hymer immobiliser


Recommended Posts

Can anyone help us get our Hymer BC584(2002) back on the road after 7 months forced lay up due to a problem with the starting of the vehicle? The problem we have is that when the ignition is turned our immobiliser light sometimes does not go out indicating the immobiliser is not disengaging and the van will not start. We have consulted various auto electricians and the Fiat main dealer who has run a diagnostic and came up with no faults but a possible low voltage on the initial surge but says a new battery is not the answer but do not seem to know what is. We have a solar panel which should be trickle charging the battery so it should be at optimum charge at most times. We have charged up using the mains input also and we still have the intermittent problem which means it is too unreliable to use. Anyone out there know of a similar problem and how it was solved? Can the whole immobiliser be bypassed or disconnected as I am quite willing to compromise security if we can at least use it!!
Link to comment
Share on other sites

Hi Parrot,

Your problem is not easy to diagnose The electronics controlling these vehicles do seem to be sensitive to voltage. as yours is a 2002 model are you still running on the original battery? although you are keeping it charged it is possible thart the cells have lost some of there capacity and when starting is dropping the voltage lower than the ECU likes.so it might be worth while having a discharge test carried out on your battery to eliminate this from the problem.

Also have you a vehicle alarm fitted other than the Fiat immobiliser, the reason I ask is that last year the retro fitted alarm system om my Swift developed a fault due to faulty installation and scrambled the Fiat immobiliser and not allowing the vehicle to start. I was in France without the camper for a week while it was sorted out by the local Fiat dealer, I claimed the cost of this from my dealer on my return to the UK but could not claim for the inconvenience. hope this is of some help to you regards Geoff

Link to comment
Share on other sites

I would appreciate you giving any solutions you may find on this forum as I am having simular problems.

I have a Bürstner on a Fiat and a couple of times the key light has lit up and it didnt want to start. I removed the key and tried another time and after a couple of attempts it started ok. I then started using my red master key and didnt have any problems.

The place where I bought my van said I shouldnt use the master key so I went back to using the "normal" key.

They told me a "knowledgeable" person could re-route the system and do away with the immobiliser but it would take a few hours work (and labour costs)

It has been ok for a while but the weekend before last it did it again.


I asked Fiats and they could offer no advise as the fault was too intermittent. They suggest I use the normal key and take the master when I go away.


So there you go, I'm going to Wales for three weeks on the 7th August and I am keeping my fingers x'd.


Hope you get yours fixed and please let us know how.




Link to comment
Share on other sites

Hi Geoff


Thanks for the suggestion I will get the battery tested. Seems to be starting better after a sunny day when the solar charging has maxed the battery so could be its not holding its charge for long. Re the alarm we did have a retro fitted but had it disconnected as it was thought it was causing a different starting problem

Link to comment
Share on other sites


Check your fuse box. I have found sometimes the immobliser is connected to the back of one of these fuses. You will have to look and find it for yourself as, I cannot tell you on this site the exact location.

When you find the connection dissconnect your battery first, then open ithe poor connection and remake the connection with a solder joint. The poor connection gives voltage drops and I have found gives intermittent problems. Also check the fuses are tight and the earth to chassis is good . You may need to replace some of the fuses if the are cheap type.

If you have some old copys of MMM Clive covered an excellent article on Fuses some months back.



Link to comment
Share on other sites

I had a similar problem on a 1993 peugeot 2.5 TD. Auto electrician said that there was a voltage drop from the ignition switch, through the immobliser / alarm circuit, to the starter solenoid. He inserted a relay before the solenoid, this turned the wire to the solenoid into the signal wire to the relay, and then a bigger cable from relay to solenoid which came straight from fuse box. So no volt drop. Worked a treat.

I could've done this job in a day, but he did it in 30 mins and charged £45 !




Link to comment
Share on other sites


This topic is now archived and is closed to further replies.

  • Create New...