Do you know your car's MoT and mileage history? Our user profiles will show you for FREE | No thanks
1997 Immobiliser Problem - duffers
My immobiliser has immobilised my 1997 Jeep really well. However, I cannot now mobilise. I have re-programmed the fob, changed the batteries, disconnected the car battery, tried the main dealer, tried auto electrics company, all to no avail. I would be happy to have the system removed but am informed the system was fitted when it was imported and is an integral part of the wiring system and impossible to take off. I had even done the honourable thing and had it converted to LPG.

Any ideas or suggestions how to get me back on the road would be greatly appreciated

Subject Line corrected to put make before model - PU

Edited by Dynamic Dave on 03/07/2008 at 20:54

Cherokee Jeep Immobiliser - Screwloose

Ring an auto-locksmith from the yellow pages?
Cherokee Jeep Immobiliser - bell boy
if as you say this is an after fit immobiliser then any decent auto electrician can sort this for you quite easily
i have had to do loads of thatcham fitted immobilisers these last years and im not a time served auto electric man so a man that can should
Cherokee Jeep Immobiliser - Aprilia
Jeep electrics are dreadful at the best of times, so I sympathise.

Normally the immobiliser is spliced into the wiring so that it can interrupt three or more circuits (e.g. starter, fuel pump, ECU etc etc). This is normally done in some hard to find place like buried right under the dashboard - so it could be an awkward job. Your best bet is probably to contact an alarm fitter who will know the 'usual' places that the splicing is done on this vehicle.
Cherokee Jeep Immobiliser - MerlinTec
Even though this is an add on for the uk market you car did have a immobiliser from new in the roof with RKE fob interface but this didn?t conform to uk thatchem speck. so this was removed and a new thatchem one fitted under the steering wheel that incorporates the RKE for you locks. The engine ecu needs to get a signal from one of the immobilisers to allow the vehicle to start if not it will start and run for 2 or 3 seconds then cut out.
Does you car start at all? If it doesn?t it?s unlikely to be your immobiliser at fault. More likely it?s the crankshaft sensor. Does the dash all work, fuel gauge, battery voltage?
Cherokee Jeep Immobiliser - Jeep Orvis

I have read your earlier emails and you appear to know your stuff on this subject.

My 97 Jeep Cherokee Orvis was working fine but stopped working last week, it will turn over, lights come on etc but wont start.The garage has given all clear on crank shaft, run diagnostics and reckons its the immobiliser. Our next option is to spend a small fortune at a Jeep dealership with no guarantee that they are able to do anything, do you have any tips or knowledge of how else to resolve the problem?

Even more painful as just had the head cgasket done 2 weeks ago so would hurt to scrap 2 weeks after spending £1100.....ouch!!

Many thanks

Cherokee Jeep Immobiliser - MerlinTec
Whatever you do don?t scrap it, need more info on what you have. Do all the gauges work? Did it start and cut out? Do you have spark/fuel? Do you hear the fuel pump prime? Did the garage get any fault codes? Did their machine communicate ok with the jeep? Did it break down on you or just not start?
Cherokee Jeep Immobiliser - zena
I've been reading these posts with great interest and wonder if anyone out there can help us.

We've got a Jeep Cherokee Sport (auto) 1996. A couple of weeks ago my husband went to the local shop (about 2 miles) and the engine just shut off, leaving him in the middle of the road with two tons of hard-to-steer metal.

Since then it has been in the garage twice. The rotor arm has been replaced as that seemed to be the problem. It conked out again. So a new coil was fitted. I drove it from where it had been repaired half a mile down our track. It went fine. Next morning Evan warmed it up and I followed him in my car down the track (a mile). At the bottom gate it conked out, and would not re-start. I checked it a couple of hours later and it started perfectly. The next day Evan started it up - all fine - and let it run. After about 20 minutes with the temperature gauge at normal running temp. it conked out.

Is it possible that this is an immobiliser problem? Evan would be happy for it to be disabled if it is, but how difficult is it to do.

Cherokee Jeep Immobiliser - MerlinTec
No most likely crankshaft sensor on yours.
Cherokee Jeep Immobiliser - zena
Hi Simon, Thanks for your reply. By the time I read this, our Jeep had been 'recovered' back to the Jeep dealer. They scanned it and 're-set the values'. Our mechanic said they needed to drive it until it faulted. They did, and came up with the same solution as yours - crankshap position sensor". I followed Evan the 60 miles back home from the garage this morning and everything seems to be sorted. I will definitely log on to this site again in the event of mysterious problems, but I really appreciate your prompt (and accurate) response to our dilemma. Zena
Cherokee Jeep Immobiliser - Jeepdave
a immobiliser from new in the roof with RKE fob interface but this didn?t conform
to uk thatchem speck. so this was removed and a new thatchem one fitted under
the steering wheel that incorporates the RKE for you locks. The engine ecu needs to
get a signal from one of the immobilisers to allow the vehicle to start if
not it will start and run for 2 or 3 seconds then cut out.
Does you car start at all? If it doesn?t it?s unlikely to be your immobiliser
at fault. More likely it?s the crankshaft sensor. Does the dash all work fuel gauge
battery voltage?


A while ago I bought a 97 4.0L Cherokee with LPG conversion. I was told that for some reason the keyfobs did not work, but probably just needed batteries. I replaced the batteries to no avail. I took the jeep to the main dealer to have the fobs programmed using the DRB tool, and was told that I should not really have been able to start the car without the fobs as they also activated the immobiliser. The prognosis being that the car had been got at and the immobiliser system disabled.
The manual I have indicated that the RKE system is in the overhead consol, but the manual probably does not cover UK spec cars. I have also been told that later models replaced the system from 98 with a Sentry Key system. There certainly is no module in the overhead consol
I was interested to read the text above, being that I have now had to start removing the dash and facia in order to repair the heater matrix and in doing so have discovered an unattached multi block, white in colour with many black cables under the steering wheel. I wonder if this should be attached to the RKE/Immobiliser module. 4 or 5 of the cables are cut from the back of the block, but at the moment I cannot see where they would have originally been connected.
I wonder if anyone can help with a description of the system, wiring diagram or any advice as to what to do. I am not too worried about the immobiliser but would like the RKE to work.
Cherokee Jeep Immobiliser - MerlinTec

Can you tell me if you have a round ball at the back of your overhead consol? If so if you drop the consol (2 screws at the front and slide it forwards) in the middle of the consol there should be a circuit board and it will say RKE interface. Remove this and just look at the soldered joints on the back to see if any have cracked and not making contact. If not I look up the install instructions and dig out my 97 service manual.
Cherokee Jeep Immobiliser - Jeepdave
Many thanks. I should have said that this is a Mk2 facelift cherokee. I think only the mk1 jeeps had the ball on the overhead consol, and also had a IR rather than RF RKE type system. I did take the overhead consol off some while back, and there was no module in there, and no apparent loom for it either, though the 97 manual I have suggests that it should be there. The manual I have is I think for US models though. Your manual might be different, hopefully. Cheers, David.
Cherokee Jeep Immobiliser - MerlinTec
No my manual also say it should be in the overhead consol so I pulled the UK install instructions for the may and scofield immobiliser and the unit comes with 2 fobs pre programmed into it. So I guess you will have to wire this unit back up or replace it if missing or faulty with a new may and scofield unit or an after market unit to get the RKE to work.
Cherokee Jeep Immobiliser - Jeepdave
Hi Merlin,
Dont suppose you know where the unit is supposed to be? Or by chance have the wiring diagram for it. I think the unit must have been removed as the DRB tool at the dealer could not program the fobs. Sounds like unless I can get a second hand replacement, it will probably be cheaper to get an aftermarket kit though.
Cheers, Dave.
Cherokee Jeep Immobiliser - MerlinTec
It should be under the steering colume. loads of black wires going to it.
Cherokee Jeep Immobiliser - Jeepdave

Damn!! There is the multi plug, the unit is missing and about 4 wires from the multi plug have been cut, and I cannot see where they went.

I think it is time to upgrade the RKE/Immobiliser on this one.

Thanks for all the info.
Cherokee Jeep Immobiliser - Jeepdave
Interesting thought..........

I wonder if I ended up buying my Jeep from the guy who originally posted this thread?
Cherokee Jeep Immobiliser - vantard
Reviving and old thread! I have exactly the same problem and was wondering if anyone has ever found a fix?

My '97 diesel cherokee has the May and Scofield immobiliser and it now appears completely dead despite having a live feed to it. With it disconnected the engine will run and cut out after a couple of seconds.

Question is how to get over the problem? Do I need to find a matched used ECU/immobiliser unit and key fob? Can I convert it to run without an ECU. I just want to be able to run it off road and get some use out of a usable vehicle rather than throw it away for scrap!

Any suggestions gratefully received...

Cherokee Jeep Immobiliser - Zibby

Looks like quiet few here have problem with immobiliser in jeep Cherokee, but still no solution :/

Mine just not start at all, even for few seconds. Once i just wanted to go somewhere and can't start it at all... On the dash orange icon - crossed key - stays solid ON anytime when ignition is ON, and red led on overhead console stays solid ON anytime battery is connected.

Stuck now on the drive for 4 months... and cant find solution. Tryed few:

-disconected battery for 16+hrs, connected again

-two different guys tryed to connect with laptop to read fault codes - both laptops doesnt ''talk'' with a car

-autolocksmiths checked - keys transponder seems to be ok

-decent autoelectric tryed to go through

-camshaft position sensor checked - ok

No luck at all....

Do anybody find maybe solution for jeep immobiliser problem yet?

Thanks a lot for any info.


Edited by Zibby on 22/11/2013 at 20:41

Cherokee Jeep Immobiliser - Zibby

*Crankshaft position sensor (not camshaft) checked - ok


Ask Honest John

Value my car

Amount to borrow
Sorry. The minimum loan amount is £1000
To pay back over

My credit score

Best available rate 9.20%

Total repayment £9,304.93

Total cost of credit £1,804.93


60 monthly payments

Apply now

Representative example

The Representative APR is 13.2% (fixed) so if you borrow £7,500 over 4 years at a rate of 13.2% p.a (fixed) you will repay £199.21 per month and repay £9562.20 in total.