Engine immobiliser problem

funkey_monkey

At the weekend I changed the case of a key fob for an Isuzu Rodeo as the tab for holding additional keys was broke.
However, it will not now start the vehicle. The fob will open and close the central locking.

The jeep turns over, but the fuel has been cut off and the immobiliser light remains illuminated. A spare set of key does start it.

I've tried disconnecting and then reconnecting the battery, but no avail.

Can anyone help, as I want to get this resolved.


Thanks.

Irish Steve

At a guess, there was a piece in the old key head unit that didn't get transferred over to the new head, and that's the critical piece that is interrogated by the imobiliser, so at present, it's not being seen, so the imobiliser is not unlocking. To look at, it's probably less than 1 cm by 3mm x 2mm, and does not look like it's electronic. It may well have fallen out as the old unit was taken apart, in some keys it's only sitting in a slot, and not fixed as such, so if that's the case, you may need to have a very close look at the place where you did the swap, in case it's lying around (or on the floor). The other possibility is that it didn't fall out of the old case, and is still attached to it.

As you have a working second key, very carefully, over something like a white sheet, have a close examination of the key that does work, and look for the relevant piece.

funkey_monkey

Thanks will check later.
I thought this would have been attached to the circuit board?

magentis

funkey_monkey wrote: »

Thanks will check later.
I thought this would have been attached to the circuit board?

No.In some keys it's seperate and is just a little bit bigger than a cooked grain of rice.

funkey_monkey

Balls! I hope I haven't lost it.

Thanks.

funkey_monkey

Can it wait until weekend is does it need to be done ASAP?

Irish Steve

The chip won't be affected as such, I have 2 keys for a similar vehicle, one of them hasn't needed to be used for close on 10 years, but it still works fine.

Roberto_gas

funkey_monkey wrote:

I've tried disconnecting and then reconnecting the battery, but no avail.

U lost the transponder chip...get it from old key case and xfer it to new case...shud be fine then..

Roberto_gas

funkey_monkey wrote:

Can it wait until weekend is does it need to be done ASAP?

U can do it anytime...just dont make the battery go flat trying to start the car

Cordell

Bring the old case near the ignition, if it starts then the transponder chip it's still inside. It's a small piece of plastic, usually with some writing on it, not connected to anything and with no visible wires coming out of it.

scamalert

Cordell wrote: »

Bring the old case near the ignition, if it starts then the transponder chip it's still inside. It's a small piece of plastic, usually with some writing on it, not connected to anything and with no visible wires coming out of it.

spot on, on older cars the immobilizer chip would be molded into plastic with key, newer cars have it inside casing glued or lose its tiny as mentioned not larger then rice grain, but easier way is to bring old casing as close to ignition and use the key if it starts will mean you didnt lose it and just need to extract it carefully and place it in new casing.


If you lost it, cheaper option might be getting used key with chip and programming it to your car, but depends on model and other factors which way to go about it.

funkey_monkey

Bollox - the bloody thing is glued in place. Little wonder I missed it.

Any ideas about how I can access it without causing more harm than good? I presume it is just a matter of grinding it out - there is no secret solution to removing the glue?
Doesn't really look like factory workmanship to me - is this common?

funkey_monkey

Google Images is sh1te.

Stoolbend

If you can get a sharp blade down between the chip and the plastic housing you should be able to dig it out.

funkey_monkey