Engine Swaps - Using an Immobilizer ECM

[atomic_hoji]

This thread is to document the process I used to get an Immobilizer equipped Engine Control Module (ECM) running a 2ZR-FAE from a 2016 Scion iM 6MT to work in a 2018 Toyota Yaris SE 5MT. While my experience is specific to this swap (found here: 2018 Yaris SE 5MT - T-Sport w/Valvematic! (http://www.yarisworld.com/forums/showthread.php?t=58839)) I will try to write it as an overview of steps to follow so that another user has a sort of guide to follow when trying to pursue a different vehicle source engine swap.

Over a few posts I will cover the following sections:


Information Resources
Verifying Compatibility
Registration ('Handshake') Process
Troubleshooting


I will spread each out over a few posts knowing I have a bad habit of drafting huge posts. :biggrin: This will also leave room to add updated information, pictures, etc.. in later.

-- Adam

[atomic_hoji]

TIS Techstream (https://techinfo.toyota.com/techInfoPortal/appmanager/t3/ti?_nfpb=true&_pageLabel=ti_home_page)
It is extremely worthwhile to get a 2-day TIS Techstream subscription and download the workshop manuals for your Yaris anyway if you plan to do any repairs on your own, but it is absolutely necessary for analyzing parts and wiring for an engine swap. While fairly tedious to open, print to PDF, name file, etc.. I found that once I setup a pattern of naming manual pages it went fairly quickly and the 2-day subscription was enough to get everything I needed. I recommend downloading the complete Electrical Manuals and Repair Manuals for your Yaris and the donor vehicle. At minimum you will need the Electrical Wiring Diagrams (EWDs), aka System Circuit Diagrams, and all the respective engine and security sections of the Repair Manuals for both the Yaris and the donor vehicle. The complete Electrical Manual will have the Fuse List, Location, Overall, and System Circuits sections and you will likely use them all at some point chasing down wiring comparisons.

Code Scanner
If you have a Windows laptop to run the Techstream software and the compatible diagnostic cable then while your subscription is active you will be able to read all the Diagnostic Trouble Codes (DTCs) from the ECM via the Techstream software. This is the best way to find out what is going on if you run into trouble. However, I have found that a generic Onboard Diagnostic (OBD2) scanner is still very useful as it will give you the generic OBD2 codes, which give you a starting point to work from - it is important to know though that not all DTCs are thrown via OBD2 and some codes may have different meanings for different manufacturers, e.g. B2799 that you may run into during registration is an engine immobilizer communication error for Toyota, but a suspension control circuit open on a GM vehicle. Depending what details your code scanner provides you may need to do some research.

...

Another resource I found was the following forum post on Club Lexus: Engine ECM, Immobilizer and Smart Key - Assistance needed (https://www.clublexus.com/forums/is-2nd-gen-2006-2013/721983-engine-ecm-immobilizer-and-smart-key-assistance-needed.html)

[atomic_hoji]

There are different types of immobilizer systems, but the one used in the 3rd gen Yaris (and likely the 2nd gen, but I would have to see the workshop manual) and Scion/Corolla iM (and likely the regular Corolla) is centered around a Transponder ECU. This central hub is connected to the Transponder Key Coil at the ignition where the key is entered and detects the key ID. If a valid key is detected, the Transponder ECU then communicates with the main engine ECM that it OK to start the vehicle. From the bit of legwork that I've done, it seems that Toyota/Lexus use this system in most (all?) of the modern cars - older Toyotas and of course other manufacturers may use different systems or the same style system but using a different communication protocol.

Using the Electrical Wiring Diagrams (EWDs), aka System Circuit Diagrams, is the easiest way to see how the system is setup, and is how we check that the wiring will match - or what wires need to be modified if they don't match. For all wiring comparisons that I do I pull each up and side-by-side; left side is what I have, and right side is where I'm going. It's not an infallible system, especially when you end up with dozens of EWDs open, but it generally works. I've put an example below of the EWDs for the Yaris Hatchback (left) and Scion iM (right).

59567

In doing our engine swap, we have all the components on the Yaris up to the point where the Transponder ECU is connected to the ECM - we know those components work together. The next step is to verify that the wiring and communication protocols between the Tansponder ECU and the ECM match.

Luckily, in this swap the wire terminals from IMI and IMO on the ECM connectors correspond, so we have no wiring changes to make. If you did need to modify the wire terminals on the ECM connector use the last pages of the EWD to match - don't forget to verify the size of terminals as well; that can bite you!

What is not shown is how the Transponder ECU communicates with the ECM. I can't post the whole workshop manual section, but recommend having a read through the section ('Theft Deterrent' or 'Wireless Door Lock' or similarly named chapter found under the 'Interior' section in Toyota manuals) and determining how the signals are sent back and forth; you're looking for waveforms for EFII and EFIO. In this case both systems use the same communication protocol (signal) to communicate, so they should be able to talk.

Given the system components, wiring, and communication protocols match we should be able to make them talk to one another. The part not shown here is that each component has a unique ID, and each ID must be valid to work in the chain of components. Setting the ID is the next post.

[atomic_hoji]

As noted above, in order for each component in the chain to communicate they must have valid IDs linked to one another. The process of setting these IDs is called Registration. In our engine swap case where we are swapping only the engine ECM and no other component in the Immobilizer system, we only need to register the ECM's communication ID with the Transponder ECU. Referring back to the Toyota manual chapters noted above there are different procedures depending which components were replaced. In the 2018 Toyota Yaris manual the process is covered by step 8. Procedure 'E', also referred to as the 'handshake' procedure, as follows:

WARNING - Ensure you understand what you are doing before following these steps! There are notices in the workshop manual that are very important, e.g. limits on number of tries before Transponder ECU is unusable.


Jumper TC and CG on DLC3 (OBD2 port) using SST
Turn IGN to ON position
Wait 30 minutes
Check that engine starts


Here's my rendition of the SST - it's a piece of wire. lol
59569

The instructions don't list when to remove the jumper, but I found that (as indicated) it did not start on the first try. I returned the key to the OFF position, removed the jumper, and then started the engine. Assuming the rest of your swap is setup correctly, the engine will start and run if the registration process was successful.

If your engine does not start successfully it's time to start troubleshooting - this could be the immobilizer or, as I found, it could be some other issue with your swap.

[atomic_hoji]

Troubleshooting afterward - because sometimes it's not the immobilizer (and sometimes it is..)

[tmontague]

great idea for a separate thread on this, looking forward to seeing how you got this to work.

I assume the techstream was the turning point as I'm pretty sure the dealership can make a new ecu mate up to the original immobilizer ecu located at the ignition

[ArmstrongRacing]

This is so awesome. Great work man!

[atomic_hoji]

Updates to the original post completed today; need to rough out a troubleshooting section. Since I didn't end up having trouble with the Immobilizer system I'm not sure how much I'll have to write in that regard. Figure I'll make a note of some other things that I did run into and leave it for room to grow as we collect more information - as hopefully some more folks will give it a try and we'll have more information to collect and document.

great idea for a separate thread on this, looking forward to seeing how you got this to work.

I assume the techstream was the turning point as I'm pretty sure the dealership can make a new ecu mate up to the original immobilizer ecu located at the ignition

I actually only used Techstream to download all the manuals for the two vehicles; due to some other issues that are not Immobilizer related I have ordered a fairly inexpensive Techstream compatible cable now, but I didn't need it to complete the registration procedure. It turns out that the registration procedure is actually fairly straight forward once you establish that the components you have can communicate with each other. And I don't mean to say that to put anyone out about using the non-immobilizer ECMs; it was a gamble that they would actually communicate correctly based solely on reading the workshop manuals and finding the post of a successful swap of a 2UR in place of a 2GR in an IS350 on the Club Lexus forums. The dealer making it work was in my back pocket as a last resort if the registration or a bypass trick didn't work out - I was not looking forward to explaining what I had done to a dealership if I didn't have to, lol.

In hindsight I wish I'd pulled the manuals for the 2nd gen. Yaris and the Scion xD for better comparisons, especially because there are xD components that I ended up using. I'd really like to run down the 2nd gen., Corolla, and xD EWDs and see how they compare.

This is so awesome. Great work man!

Glad I can contribute back to the community with some information that is (hopefully) useful to the next person. :thumbsup:

-- Adam

[CrankyOldMan]

Glad I can contribute back to the community with some information that is (hopefully) useful to the next person. :thumbsup:

-- Adam

Absolutely! This means that there are other possibilities for us in the future, like a stock 3ZR swap. :thumbup: