Rev 1 to Rev 3 NA Conversion

Discussion and technical advice the SW20 MR2. 3S-GTE, 3S-GE, 3S-FE etc
Anything and everything to do with maintenance, modifications and electrical is in here for the Mk2.

Moderators: IMOC Moderators, IMOC Committee Members

Post Reply
Stefen
Posts: 185
Joined: Thu Nov 10, 2005 12:12 pm
Location: Northern Ireland

Rev 1 to Rev 3 NA Conversion

Post by Stefen »

After pulling out the Rev 1 engine and lifting into the Rev 3 I was very pleased indeed to discover that almost everything fits and lines up, including the connectors in the engine bay fuse box.
Having got the Rev 3 ECU with the engine I fitted it and inserted all the connectors, but there is one which is a different shape which connects to the Rev 1 loom:

Image

Image

Image

Has anyone overcame this issue before?

I have the loom from the old engine and was thinking about cutting off the connector and soldering it onto the Rev 3 loom, but there are more wires on the Rev 3 loom, so I'm unsure as how to proceed!
Stefen
Posts: 185
Joined: Thu Nov 10, 2005 12:12 pm
Location: Northern Ireland

Re: Rev 1 to Rev 3 NA Conversion

Post by Stefen »

This wire is called the "ENGINE WIRE AND ENGINE ROOM MAIN WIRE", it is referred to as the EA1 in the electrical diagrams.

So, on the Rev 1 connector there are 5 wires:

Blu/Wl
Blu
Blu/Or
Red/Gr
Blk/Wh

These match up with five on the Rev 3 side. So going through the diagrams their purposes are as follows:

Blu/Yel - Cooling fan light
Blu - Engine cooling fan temp sensor
Blu/Or - Engine cooling fan temp sensor
Red/Gr - Engine lid switch
Blk/Wh - Ground for (Ign or Starter relay, not sure yet)

The left overs on the Rev 3 side are:

Brn - Speed sensor
Yel/Red - Airbag (Maybe, not sure about this one)
Gr/Wh - Engine check light

I need to double check the colours in the daytime to be sure, but that looks like the mystery solved...

Time to use the connector from the old Rev 1 engine and see what happens.
PW@Woodsport
Posts: 7642
Joined: Tue Dec 14, 2004 6:40 pm
Location: durham
Contact:

Re: Rev 1 to Rev 3 NA Conversion

Post by PW@Woodsport »

You have more than just that connector to worry about.

The 22pin ECU plug that used to plug into your rev1 ecu has different pin locations than your rev3 ECU, so quite simply it won't work unless you repin that plug.Your engine bay fusebox also has different pinouts even though the plugs fit.
Image
Stefen
Posts: 185
Joined: Thu Nov 10, 2005 12:12 pm
Location: Northern Ireland

Re: Rev 1 to Rev 3 NA Conversion

Post by Stefen »

Thanks for the hint.

As far as I can see with E6 (the 22pin Rev 1 connector which is plugged into the Rev 3 ECU) the following is my understanding:

Pins 1-11 are okay
Pin 12 Circut opening relay is also okay
Loom Pin 13 (B1) now needs to be linked to ECU Pin 12 (B) (this could be unnecessary as there may be a join in the loom.

Pin 17 (FC) on the widest connector that the ECU has now has to go to Pin 14 on E6 to also operate the circut opening relay.
(Edit: Not sure about this one - will review in the morning).



With regards to EA-3 (18 pins, engine bay fuse box) most of the pins are okay:

1-13 are fine, as are 16-18.
Rev 1 loom is expecting pin 14 to provide a signal from the ECU for the A/C clutch. However the Rev 3 is expecting to receive a signal from the Inlet Air Temp.
Rev 1 loom is using pin 15 to channel a signal from the inlet air temp sensor to the ECU. However the Rev 3 is expecting nothing.
So the solution is to move pin 15 over to pin 14's position.


The other connector in the fuse box, I haven't just go around to figuring it out, mainly due to a shortage of data. The wiring diagrams I have are all for turbos and the 94 diagram doesn't have the via routes (which connectors) for the circuts. So if someone has the wiring diagrams for the Rev 3 I would be most appreciative of a copy!
TUDE 5976
Posts: 2
Joined: Wed Nov 11, 2015 9:25 pm

Re: Rev 1 to Rev 3 NA Conversion

Post by TUDE 5976 »

I'm doing the same conversion

What wires did you join up to make the looms work with each other??
TUDE 5976
Posts: 2
Joined: Wed Nov 11, 2015 9:25 pm

Re: Rev 1 to Rev 3 NA Conversion

Post by TUDE 5976 »

With regards to the EA1 plug which wires did you move to connect up with the rev 3 loom??

Do you have a pinout list for the rev 1 EA1 plug??
Post Reply

Return to “MR2 MK2 1990 - 1999 NA & Turbo”