Topic

So ive just changed the ecu set in my car from mems2j to mems3. Not ive got the full mems3 set but ive just plugged it in to my car with my hybrid loom and its talking just fine. First question the lucas fob is turning off the alarm and unlocking the doors just fine and its from the old car.
Is this expected?
Does this mean the car will start or is it still immobilized as its not paired together and i still need to replace 5as and fob before it will start the car.?
Next question can i pair a lucas system with my ecu if i didnt have the matching set. Only reason i ask is that ive a few mems3 sets about and would be handy spares for future if mine died.
Lastly pscan has read out the eka code and its showing 2 codes. As my car is an mgf do i read the top code? See pics

Thanks as always...

To turn off the alarm and control the central locking remotely the fobs have to be linked to the alarm. If they came together then they are still linked.

This doesn't mean that the engine will start.

To start the engine the MEMS has to be linked with the alarm (by using the "learn EMS" feature).

So you need both things, fobs linked to the alarm, and MEMS linked to the alarm.

Concerning matched sets, if you have a pscan you don't need matched sets because you can match the MEMS to the alarm yourself. The only caveat is that you can't do any of this with Rover 75/ZT ECUs as they use the BMW security system. A MEMS3 from a 25,45,MGF or MGTF can all be matched to any 5AS or Pektron, or swapped in in place of MEMS1.9 or MEMS2J as well.

If the 5AS came from an MGF originally then it's the top number.

Just note that if MEMS3 ECU is remapped one then there is possibility that your MEMS3 has removed neccessitiy to have paired alarm ECU with MEMS3, meaning, you could start car without any pairing. If you start the car but it die within 2 seconds then you need to pair the alarm ECU with MEMS3.

So when I swapped over the ECU, it did as you described it started and died after about 1sec.

So I put in the matching fob and 5AS and it then worked just fine..

So you say there is a learn feature - I believe this could be super useful to me as I have loads of fobs / 5AS units that could be used to pull me out of a hole...


Imaging I have just put in any 5AS into my car just now with a matching fob - how do I pair that to the ECU?
Is this the "Learn EMS" feature you describe and if so can you please tell me the steps to use this feature?

thanks as always...
Trev.

You have a www.pscan.uk or a T4 to match the fob to the 5AS and to the engine ECU. It is really easy using the pscan by using the immobiliser fob programming option.

To match your engine ECU to your 5AS:-
1. Optional step. Log into the 5AS and change the EMS to one of your liking. If you have multiple 5AS and give them all the same EMS code then any engine ECU matched to one 5AS will be matched to them all.
2. Press unlock, make sure the alarm LED is unlit.
3. Switch on the ignition.
4. Log into the engine ECU.
5. Select immobiliser, or extra functions (depends on the ECU).
6. Select Learn EMS.
7. Follow the on screen instructions.

Great news, thanks for this instructions....

And its even better that I can program them to have a matching EMS code that means they are interchangable should one fail in the future.

Last question on this subject I promise...
For reference is the same kind of programming / matching available on the pektron set?

Can I follow similar instructions to match any pektron to any ECU assuming I still have a matching fob to unlock / immobilize it first.?

Thanks as always, trevor.

I don't believe that it's possible to change the EMS code on a Pektron (except by sending it off to Technozen, maybe).

The feature in the engine ECU to match it is exactly the same with Pektron and 5AS.

Additionally an engine ECU that matches to a 5AS will also match to a Pektron and vice versa. The format of the code on the wire seems to be the same with Pektron and 5AS.

The same is true with early Freelanders which had an EMS code in the body controller.

The Rover 75 and later Freelander went to the BMW system and these are not interchangeable with 5AS/Pektron.