[Mk2] [Turbo] Rev 3 traction control

[alexturbo]

Have converted my rev2 to rev3 ecu and come across the code 47.
Looked about on here and looks to be related to the traction control so my question is do all rev3 have trc??
If not how do Toyota get around this because all there only seems to be one ecu part number?

[toxo]

No, not all rev3's have TRC. I would wager that you've got something connected to one of the TRC pins on the ECU that shouldn't be. That said I can't see 47 listed in my BGB.

[djpkins]

The traction control seems to be intergrated with the abs system, both physically and electronically...did the rev 3 ecu, that you've fitted, come from a t/c model?

[toxo]

The traction control seems to be intergrated with the abs system, both physically and electronically...did the rev 3 ecu, that you've fitted, come from a t/c model?

Erm, no it isn't. The ABS and TRC share wheel speed sensors but that's it. And all the ECUs are the same as far as I know, regardless of whether the car had TRC or not. It does have some pins that connect to the TRC system (labelled up like a second throttle position switch) but TRC itself is a separate box.

[alexturbo]

That's exactly what I'm saying if the ecus are the same Toyota must have come up with a way of bypassing the trc error on the no-trc models.

[dazzz]

When you reset the ecu does the code come straight back up or do you have to drive it?

[alexturbo]

It's there all the time. Even left the battery unhooked over night and it still came back straight away!
Going to remove the wire currently in the trc pin hole as suggested see what that does.
Could it just be a case of bridging the sensor earth and the trc pin?

[djpkins]

I reckon if it was as easy as removing the T/C butterfly and a bit of wiring to the speed sensors...T/C upgrades would be available on the second hand market...when i took the loom out of this T/C rev3, there were T/C boxes, the abs ecu under the dash had "T/C" on it ... I'm sure it's not "plug and play" without extensive modfication to a non T/C car...but everything i say is just an assumption based on what I can see on this loom here, I have never tried to fit this type T/C to another Mr2, and can't find a thread on anyone who has...which more than likely means it's too much work to do it.

[alexturbo]

Granted I'm sure it's a hugely complicated job to convert but Toyota wouldn't have made it that difficult to bypass an error code on a model without trc fitted. This is all asuming that the ecus are the same???

My ecu is as follows
89661-17450
175700-5671

[jon]

Does your ECU definitely read 89661-17450? All the Rev 3 ECUs I've seen are 89661-17460.

89661-17450 is listed as a California spec ECU:

CALIFORNIA SPEC
89661 89661-17420- 211420 MR2 01 9201-9311 SW21..CP..ATM
89661 89661-17430- 211420 MR2 01 9201-9311 SW21..MTM
89661 89661-17440- 211420 MR2 01 9311-9506 SW21..MTM
89661 89661-17450- 211420 MR2 01 9311-9506 SW21..ATM
89661 89661-17470- 211420 MR2 01 9311-9506 SW20
89661 89661-17510- 211420 MR2 01 9311-9506 SW21..MTM

[alexturbo]

Sorry yeah it is 17460 bloody tiny keys on my phone!!

[toxo]

I'm sticking with my theory of you having left something rev2ish connected to one of the TRC pins.

A lot of rev3 ECU diagrams that are floating around are actually mislabeled GT4 ones. You can spot them because they have pins like INT, LEV, etc. This stems from the fact that the rev3 ECU PCB has those names written on the pins (same PCB used for both ECUs).

My understanding from when I looked into my ECU conversion is that the signals from the 2nd throttle position sensor are fed through from the TRC ECU to the stock ECU onto pins IDL2, etc.