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[rjs20]

Hi apologies for another immobiliser post, but I have searched for hours and cannot find whether anyone has managed to remove the May & Scofield immobiliser from their ECU by having it reprogrammed ?

I am in the UK and have a Jeep Cherokee 2.5td, 1999 . (Engine is a VM425 OHV) It was running fine up until a few months ago when it developed a fault with the immobiliser. It is fitted with a May & Scofield unit Model number CIS5810/1 which were fitted on import to the UK by Chrysler imports to comply with Thatcham spec I suspect that condensation has caused an issue (pooled water was present where the immo unit is fitted into the overhead console

The immobiliser LED light which is fitted at the front of the the overhead console above the mirror is staying on permanently (it flashes when it is disarmed) - the remote keyfob is working which normally will deactivate the immobiliser. The engine turns over but will not fire - I am confident that it is an immobiliser issue rather than mechanical. I have tried all the usual disconnecting the battery, leaving the ignition on etc - no fault codes on the ODB- the switched live feed comes from the overhead computer display rather than the rear wiper switch on earlier models. I have checked continuity from the immobiliser across the RKE interface all the way down to the 2 multi plugs in the drivers footwell and all is good.

The transponder ignition key is being recognised as the dashboard key light goes off within 2 seconds and as stated the engine turns over.

I am informed that the immobiliser is coded with the VIN - and that in order to run the ECU needs to receive a code from the immobiliser - the immobiliser cannot be removed or exchanged for a replacement unit as they are individually coded to each other. Steady red light possibly means that the immobiliser has lost the VIN. Recoding can only be done on the vehicle with a DRBIII with a security card from Chrysler. My local Jeep dealer doesn't want to know as they tell me they don't have a DRBIII and wont support vehicles over 10 years old.

There are 2 control units in the XJ and I have googled and both are listed as ECU’s ?

1) Behind the dashboard above the drivers footwell is a Bosch Unit P56041433AD (028100775) I think its commonly referred to as an EDC 15 / EDC15VM? )


2) In the engine bay is a Motorola box S/N 03A027AP2J46 Chrysler P/N P56041 (336AB)  (PCM?)

There are quite a few companies that offer immobiliser removal from a Bosch EDC15 ECU (usually VAG) but I cannot  find anyone who has experience of removal from an XJ ? Is there anyone on this forum who has experience of this or can offer any advice ? Is the Motorola unit also linked in with the software ?

I would really appreciate any advice !

many thanks

[Dutch]

Apologies RJS,

We are a somewhat in the middle of saving this place.

Have you tried the search function?

Please be patient, a grownup will be along shortly.

[JamesH]

If it is 1999 it probably isn’t the May and Schofield unit. Do you have a grey and round / oval key? This is what I expect all 1999 models to have and is the SKIS system (sentry key). It is in the ECU and linked to a reader ring around the ignition.

From your description it doesn’t sound quite like the SKIS system. That would be a good thing as there are more threads about sorting out the M&S system and I think it’s less complex than a lot of other immobiliser removals.

Do a search here for immobiliser removal and you should get some decent results.

[Jonny Jeep]

Googling the immobiliser part number reveals it is a M&S unit. The first link was one on ebay. I'm surprised to see that as the ignition key symbol on the cluster would indicate SKIS is fitted, as I'd expect for the year. I though the SKIS was Thatcham approved though.

Since the SKIS is programmed to the PCM with the VIN, I wouldn't have thought it necessary to have a separate immobiliser tied to the VIN. IIRC from the 97 TJ M&S threads there was an option to have M&S add a touch key to the immobiliser. Might be worth contacting M&S themselves for more info on the immobiliser, and what they might advise.

https://www.may-scofield.co.uk/about-us/contact-us/

I've had my 97 TJ have continuous immobiliser light in the past, I usually just sit doing long (1-2 second) presses of the arm/disarm buttons when that happens. I can't remember if I turn the ignition on and off at all, or just sit with it on, as it's a while since it last did it and I've slept since then.

[rjs20]

Hi - thank you for the replies to date - tried to attach a pic of the key & fob but wouldn't work its the round grey key. I don't believe the sentry key is the issue as the key light on the cluster goes out after a few seconds as it should which indicates the key is being recognised. I am in touch with Del Lloyd at May & Scofield - it is possible that the immobiliser has lost its programming. These units can only be reprogrammed on the vehicle with a DRBIII machine with a security card from Chrysler- I'm in Newcastle upon Tyne and Ive tried a few Jeep dealers in the North East - none of whom have the DRBIII machine and would have to hire it in from Jeep UK - my local dealer doesn't seem interested and have no experience of the issue having only been Jeep dealers for 3 years. They are quoting me a ball park figure of £1200 to try and rectify the problem- and have said in their opinion bearing in mind the XJ is over 20 years old it isn't worth it. they will not disable the immobiliser or try and reprogram with a 2nd hand unit if I could find one. Hence I am trying to find someone who can remove the immobilser from the ECU. I believe the immobiliser is a Bosch EDC15V-5.5 lots of companies have said they can remove the immobiliser function but only if it is for a VAG vehicle. One company said the onboard chip is 'read only' and cannot be overwritten to remove the immobiliser, and the chip would have to be replaced - so far I haven't been able to locate anyone who can carry out that work.

I have read all posts in regard to M&S immobiliser problems - on earlier XJ's M&S units were fitted beneath the dash next to the Chrysler unit and they could simply be unplugged and then plugged back into the Chrysler unit. I haven't found one single post from anyone who has managed to sort it when the M&S unit was situated in the overhead console ? (Other than those with petrol XJ's who bought 2nd hand ECU's from the USA) Since mine is a diesel - I haven't got that option?

I have tried the remote arm / disarm countless times with ign on & off - disconnected the battery for days hoping but nothing is working. The XJ is in great condition, and Ive gone through many hours replacing heads / rebuilding the transfer case etc - any help is appreciated as I'm running out of options !

[JamesH]

It sounds like you need to track down someone with the DRBIII scan tool and security card. I can think of three people I know that might have it but they are all southern. Maybe someone else will know a northern member with it.

I might be at risk of being stoned on here for suggesting it but try asking on the Birtys Facebook group too. There are members on there that aren’t on here.