97 TJ immobilizer problem solved

the jeep hasn't turned a wheel for 7years because of illness so l will check starter and wiring it could be full of muck which earth wire should l look for please.
As well as rodent damage. Check and recheck all wiring.
 
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The ECU I ordered from Flagship One left me in the same situation as you John. Sent it back. You are better ordering with @Wranglerfix. It was a more expensive unit but it arrived quickly and he's a pleasure to deal with. Got my 98 TJ going again and I even might have a few more horses to boot. Hope you get sorted.
Thanks lm going to remove starter and check that and earths first see how that goes fingers crossed !!!
 
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the jeep hasn't turned a wheel for 7years because of illness so l will check starter and wiring it could be full of muck which earth wire should l look for please.
There isn't any power getting to the starter motor from the key has anyone any ideas please ?
 
Right guys,

I am aware that the 1997 Wranglers in the UK have a certain immobiliser installed that is not the SKIM system installed into the 98 onwards models.

I am also aware that these May & Scofield units have problems, I unfortunately had the issue where the immobiliser would not deactivate using the key fob and the jeep was basically dead.

FEAR NO MORE! I HAVE THE ANSWER!

After lots of research I figured out a way to bypass and remove the unit eliminating the dreaded May & Scofield unit.

You are going to need a new reprogrammed ECU, I found a company called Flagship One based in NYC who sent me out a new ECU for £220 including postage. As far as I'm aware this is the cheapest I could find, they took my VIN number and basic info of the Keep gave me the quote called me up for payment and then it was just a case of me waiting for it to arrive.

Before you get all excited and throw your new ECU in there is something you need to do first, remove the immobiliser, this is located behind the guage cluster (you might have noticed thats where the click comes from when deactivating the immobiliser)

If you dont do this you risk the chance of it locking your new ECU out and you're back to square one..

To remove this is pretty simple here are the steps

1. Remove the 'knee plate' under the steering wheel. 2 screws hold this on

2. remove the long defrost panel

3. One this is done you will be able to access the screws for the plastic bezel surrounding the guage cluster. 2 on the bottom and 3 on the back near the windshield.

4. One this i removed you will be able to see the 4 screws holding the guage cluster to the dash, once you remove these the cluster pulls right out.

5. Now this is where it get interesting. You will see a blank metal plate. You will need to either try get behind where the studs are with your fingers and remove the nuts OR just drill the studs out.

6. Once you do this the plate will come away and you will see the black immobiliser attached to the back of said plate! Unplug this and (preferably) have a bonfire with it!

Now you are ready to install your new ECU

BE AWARE IF YOU REMOVE THE UNIT BEFORE YOUR NEW ECU ARRIVES YOUR JEEP WILL BE DEAD

The ecu is located behind the battery.. pretty simple to swap out just remove the battery take off the cover remove the 3 big clips, 4 screws and it comes away very easy.

I hope this helps anyone who needs it as it took me alot of work to figure all this out and put it into practice
Hi
Right guys,

I am aware that the 1997 Wranglers in the UK have a certain immobiliser installed that is not the SKIM system installed into the 98 onwards models.

I am also aware that these May & Scofield units have problems, I unfortunately had the issue where the immobiliser would not deactivate using the key fob and the jeep was basically dead.

FEAR NO MORE! I HAVE THE ANSWER!

After lots of research I figured out a way to bypass and remove the unit eliminating the dreaded May & Scofield unit.

You are going to need a new reprogrammed ECU, I found a company called Flagship One based in NYC who sent me out a new ECU for £220 including postage. As far as I'm aware this is the cheapest I could find, they took my VIN number and basic info of the Keep gave me the quote called me up for payment and then it was just a case of me waiting for it to arrive.

Before you get all excited and throw your new ECU in there is something you need to do first, remove the immobiliser, this is located behind the guage cluster (you might have noticed thats where the click comes from when deactivating the immobiliser)

If you dont do this you risk the chance of it locking your new ECU out and you're back to square one..

To remove this is pretty simple here are the steps

1. Remove the 'knee plate' under the steering wheel. 2 screws hold this on

2. remove the long defrost panel

3. One this is done you will be able to access the screws for the plastic bezel surrounding the guage cluster. 2 on the bottom and 3 on the back near the windshield.

4. One this i removed you will be able to see the 4 screws holding the guage cluster to the dash, once you remove these the cluster pulls right out.

5. Now this is where it get interesting. You will see a blank metal plate. You will need to either try get behind where the studs are with your fingers and remove the nuts OR just drill the studs out.

6. Once you do this the plate will come away and you will see the black immobiliser attached to the back of said plate! Unplug this and (preferably) have a bonfire with it!

Now you are ready to install your new ECU

BE AWARE IF YOU REMOVE THE UNIT BEFORE YOUR NEW ECU ARRIVES YOUR JEEP WILL BE DEAD

The ecu is located behind the battery.. pretty simple to swap out just remove the battery take off the cover remove the 3 big clips, 4 screws and it comes away very easy.

I hope this helps anyone who needs it as it took me alot of work to figure all this out and put it into practice
Hi,

that is a lot of research so thanks and well done
I have an XJ and am looking to replace the ECU, and I read on one XJ forum ( not as detailed as this forum !) that he got the programmed Ecu and then all he did was to cut a wire ( he didn’t say which - XJ guys eh) to neutralise the immobiliser. This makes a bit of sense as the key thing must be that the immobiliser wont function , regardless of whether it’s there or not . Would you agree ?
many thanks
 
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Thank you Sam for this post. The fob for my 1997 UK import Jeep wrangler with the May & Scofield unit installed finally bit the dust after 25 years of repeated resuscitation and terror that the immobilizer would be the end of the car. We have successfully removed the immobilizer as you described (and had a bonfire with it!) Instead of buying a new computer I sent the original computer to Mark at Wrangular Fix who was very helpful in the process and removed the skim. The car didn’t start right away once the original computer had been reinstalled minus the skim and the fear was it hadn’t worked, however after testing the starter motor we jerry-ridged a starter button to override the ignition and the car now starts! This feed was incredibly helpful! Thankyou!
 
Right guys,

I am aware that the 1997 Wranglers in the UK have a certain immobiliser installed that is not the SKIM system installed into the 98 onwards models.

I am also aware that these May & Scofield units have problems, I unfortunately had the issue where the immobiliser would not deactivate using the key fob and the jeep was basically dead.

FEAR NO MORE! I HAVE THE ANSWER!

After lots of research I figured out a way to bypass and remove the unit eliminating the dreaded May & Scofield unit.

You are going to need a new reprogrammed ECU, I found a company called Flagship One based in NYC who sent me out a new ECU for £220 including postage. As far as I'm aware this is the cheapest I could find, they took my VIN number and basic info of the Keep gave me the quote called me up for payment and then it was just a case of me waiting for it to arrive.

Before you get all excited and throw your new ECU in there is something you need to do first, remove the immobiliser, this is located behind the guage cluster (you might have noticed thats where the click comes from when deactivating the immobiliser)

If you dont do this you risk the chance of it locking your new ECU out and you're back to square one..

To remove this is pretty simple here are the steps

1. Remove the 'knee plate' under the steering wheel. 2 screws hold this on

2. remove the long defrost panel

3. One this is done you will be able to access the screws for the plastic bezel surrounding the guage cluster. 2 on the bottom and 3 on the back near the windshield.

4. One this i removed you will be able to see the 4 screws holding the guage cluster to the dash, once you remove these the cluster pulls right out.

5. Now this is where it get interesting. You will see a blank metal plate. You will need to either try get behind where the studs are with your fingers and remove the nuts OR just drill the studs out.

6. Once you do this the plate will come away and you will see the black immobiliser attached to the back of said plate! Unplug this and (preferably) have a bonfire with it!

Now you are ready to install your new ECU

BE AWARE IF YOU REMOVE THE UNIT BEFORE YOUR NEW ECU ARRIVES YOUR JEEP WILL BE DEAD

The ecu is located behind the battery.. pretty simple to swap out just remove the battery take off the cover remove the 3 big clips, 4 screws and it comes away very easy.

I hope this helps anyone who needs it as it took me alot of work to figure all this out and put it into practice
Hi, my auto electrician showed me your solution for the May and Scofield immobiliser problem, we followed your advice and have removed the immobiliser and taken out the ECU. Today I contacted Flagship One but when I asked them if the replacement would work without the immobiliser no one could give me a straight yes or no. Don’t want to order it if it won’t work. Can you give me any more help, it would be much appreciated. John Ritchie. ( [email protected] ) 07899 962605.
 
Hi, my auto electrician showed me your solution for the May and Scofield immobiliser problem, we followed your advice and have removed the immobiliser and taken out the ECU. Today I contacted Flagship One but when I asked them if the replacement would work without the immobiliser no one could give me a straight yes or no. Don’t want to order it if it won’t work. Can you give me any more help, it would be much appreciated. John Ritchie. ( [email protected] ) 07899 962605.

Contact @Wranglerfix He'll help you.
 
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Sorry to bring this thread back to the top. But I've used this as a source to remove the immobiliser from my 97 UK TJ Wrangler, it was being temperamental.

With the great support of @Wranglerfix I've successfully installed the new PCM, as well as removing the immobiliser, not had the bonfire yet, from behind the dashboard, draining power in-between. But.... I still seem to have an issue with the jeep not starting on a key.

Current Behaviour
- When I turn the key the fan and stereo switch off, engine doesn't turn over.
- With the ignition on, I can short the starter motor and the engine starts quickly and runs fine as ever
- If I quickly plug the old PCM in and try to start the engine by shorting the starter, engine turns over but doesn't fire up. Suggesting new PCM works!

So what's been done to date;

1. Removed immobiliser, drained power and installed new WranglerFix PCM - DONE
2. Installed new relay - DONE
3. Engine can start by shorting the starter..

Any thoughts? My currently thinking of getting an engine starter button kit to use as a way to short the starter, as this does seem to work...

Speaking with @Wranglerfix we think there's some other gremlin in the fix... thanks for any help or views...
 
Sorry to bring this thread back to the top. But I've used this as a source to remove the immobiliser from my 97 UK TJ Wrangler, it was being temperamental.

With the great support of @Wranglerfix I've successfully installed the new PCM, as well as removing the immobiliser, not had the bonfire yet, from behind the dashboard, draining power in-between. But.... I still seem to have an issue with the jeep not starting on a key.

Current Behaviour
- When I turn the key the fan and stereo switch off, engine doesn't turn over.
- With the ignition on, I can short the starter motor and the engine starts quickly and runs fine as ever
- If I quickly plug the old PCM in and try to start the engine by shorting the starter, engine turns over but doesn't fire up. Suggesting new PCM works!

So what's been done to date;

1. Removed immobiliser, drained power and installed new WranglerFix PCM - DONE
2. Installed new relay - DONE
3. Engine can start by shorting the starter..

Any thoughts? My currently thinking of getting an engine starter button kit to use as a way to short the starter, as this does seem to work...

Speaking with @Wranglerfix we think there's some other gremlin in the fix... thanks for any help or views...

Does anyone have a wiring diagram of how the immobilizer is installed and what wires were cut to put it in place? There has to be an ignition wire in there that needs to be put back to OEM status would be my first guess.
 
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Here is an ignition switch connector diagram for a 97.

signal-2023-01-12-064340_002.jpeg
 
Hi, it would seem that I too have just fallen victim to the immobilizer of doom... I have a RHD 1997 TJ Sport (2.5) in the UK fitted with what appears to be the dreaded Scofield unit.

Red light is flashing (not solid) but unlock button on the key fob no longer turns off the light and so car won't start when the key is turned (dash lights up and radio still works tho). Replacing the fob battery doesn't solve the problem. There doesn't appear to be anything obviously wrong with the fob itself, either. Car battery is new and had full charge when I ran it a few days ago.

Thinking I would check the terminals of the unit itself, taking off the dash panel was easy enough, but any advice how you got that bloody metal plate off without resorting to drilling it out???

Thanks!
 
Finally got that b*stard plate off, below pics shows what lies beneath!!! (answer; rust!!! and dirt)

It is indeed the dread Scofield unit... any suggestions how to proceed?

Will removing this thing in order to clean it up kill my ECU/PCM?

IMG_20230806_161657.jpg


IMG_20230806_161810.jpg


IMG_20230806_161851.jpg
 
Update: After cleaning up the gunk from the connectors and re-assembling everything, I can now hear the solenoid clicking inside the Schofield unit when I press the lock/unlock button on the key fob - however, the light on the dash is now solid red and the car shuts off 1 sec after starting... Any ideas??? Have I somehow bricked the ECU??? I've tried ringing Schofield and they said one of their engineers will call me back...
 
Update: After cleaning up the gunk from the connectors and re-assembling everything, I can now hear the solenoid clicking inside the Schofield unit when I press the lock/unlock button on the key fob - however, the light on the dash is now solid red and the car shuts off 1 sec after starting... Any ideas??? Have I somehow bricked the ECU??? I've tried ringing Schofield and they said one of their engineers will call me back...

Hi,
Have you managed to sort this issue out? My TJ 2.5 1997 is doing the exact same thing..
 
Ken, I concur with Charles. I got my TJ going again and the old unit had been removed for a month or two before new one arrived. Remove immobiliser and skim before installing new ECU. I'm in Ireland also ken so if you need assistance just ask.

Hi Tommy, I'm in Tipperary and have a 97 xj sport diesel which is dead. Won't unlock the doors or turn over. Don't know if it's the fob or the may and schofield unit.