Knowledge Base - Info:- Immobiliser Transponder Wiring Guide (rev4)

Thought I'd share this one as its been shrouded in mystery for years. Basically if you are fitting a rev4 (July 96-) engine into your Mr2, the engines ECU has its own security transponder, this consists of a chipped key, a pickup coil around the ignition barrel, a gold coloured chipped box on the steering column and a black plastic transponder ecu in the drivers seat belt reel area.
The chipped key basically allows the ECU to be turned on, without it it simply won't work. Up to now there hasn't been a guide on how to get past this, deemed secret information in mr2 engine conversion circles!

So here goes....
After you have of course fitted your rev4- engine (including replacing the passenger kick well to engine bay loom).

1. Remove the pickup coil from the ignition barrel

2. Remove the gold coloured 1" cubed box that the coil runs into

3. After the wires leave the gold box they enter a white plastic electrical connector, chop the wires 6" after this connector.

4. Locate the black plastic transponder ECU behind the drivers seat belt reel trim, this unit has around 13 wires coming from it, cut these leaving around 8" of wire on the box.

5. You will notice the 5 wires that exit the gold box all have a corresponding matching wire entering the black transponder unit, connect these 5 wires up.

6. Open the boot, and make the following connections on the white plastic body to engine harness plug, all you need to do is T these into the existing coloured wires in that location.

7. Connect the black/yellow wire on the black box to the black/yellow wire in the boot plug, this is 12v IGN for the transponder.

8. Connect the white/red wire on the black box to the white/red wire in the boot plug, this is 12v battery live for the transponder.

9. Connect the white/black wire on the black box to earth, ground it to the chassis.

10. Of the remaining wires 3 of them are blue with a trace colour running through each.... these 3 wires connect to their matching coloured wires in the white boot plug.

11. Ignore the solid blue wire and also the red/white stripe wire.

12. Tape the ignition key to the transponder pickup coil and tidy the whole lot behind the boot wall carpet,

That's it, the ECU will now work without issue.
I just thought this might take the pain out of this conversion for anyone wanting to have a go. Have fun!

Paul Woods

Copyright © by MR2 Owners Club All Right Reserved.


Created : 2011-10-05 15:33:45, Last Modified : 2011-10-05 15:33:45

Technical Disclaimer 

The MR2 Owners Club and its respective owners, editors and contributors make no representations about the suitability of the information contained in the documents, materials and related graphics published on  

By using this site, you hold the site and it's affiliates not legally responsible for any damages due to advice given here. This site and it's affiliates takes no responsibility for consequences of any actions that arise from advice given. Any opinion is given with information provided by you and can not be taken as absolute.

All repairs should be undertaken by a competent and qualified technician. By using this site, you understand and agree that all advice given and followed are at your own risk and do not hold this site or it's affiliates responsible for any damages.