[Mk2] [Turbo] ECU wiring help

[b8ucks]

Hi guys,

I bought a rev 3 turbo project (non runner with a number of issues) a while ago to use on the track. One of the issues was that the previous owner cut through the loom, just before the ECU. Rather than change the engine loom, I decided to solder on new connectors to the existing (cut) loom.

All was going well, until I realised that Toyota have helpfully put in several wires of the same colour, which I am unable to identify! They are as follows:

2 thin white wires
2 thin brown wires
2 thick brown wires
2 thin red wires with a blue stripe
2 thin white wires with a red stripe
2 thin red wires
3 thin black wires

Since there is no way of identifying them, would I be able to identify them using a multimeter? If so, does anyone have any ideas what they do?

Alternatively I'm open other suggestions to resolve it!

Thanks in advance.

[b8ucks]

No one? Could do with some help!

[b8ucks]

OK bit of an update. Looking at the pinouts for the non connected wires, I believe the wires correspond to the following:

Left connector
Top row:
E01 (brown) power ground
RSO (red) ISC valve
HT1 (red/white stripe) Ox sensor heater



Bottom row:
E02 (brown) Power ground
VISC (red) AS idle up valve
IGT (white) Ignitor
M+ (Brown) Intercooler water pump?



Middle connector
Top row:
VF (red white stripe) Check connector
VTA2 (Red blue stripe) Throttle position?
Ox1 (black) Oxygen sensor
THA (Black) Air temp switch
VC (Red blue stripe) Air flow meter



Bottom row:
TE 1 (black) Check connector
VTA (white) Throttle position sensor
E2 (brown) sensor ground



Can anyone confirm or deny the above for me?

[thomp1983]

you should be able to confirm most of them yourself with a multimeter set on continuity

[thomp1983]

Also not sure if the turbo is the same but my old rev3 na ecu had the pin info printed on the pcb which you could see by removing the lid

[mr2magic]

Maybe a thing to note: toyota wiring often has two markings
1) the insulator color (single colour/main colour with longitudinal stripe of different colour)
2) silver band(s)

The bands tell you which loom the wire belongs to. This can help you find which wire it is when you have more than one wire with the same colour. Exception (as always) is brown i think, as this is always earth (as is white/black)

[b8ucks]

Hi guys, thanks for all the advice. As mentioned, I used a multimeter to look for the earths. Then had a play with the other wires and.....it runs!

Albeit rather badly. Firstly it stinks and smells as though it's running really rich.

Secondly, it hunts really badly on idle, as though it has an extremely aggressive set of cams (who knows, maybe it has!).

In any case, checked for error codes and I get:

Error 21 - OXYGEN SENSOR SIGNAL/OXYGEN SENSOR HEATER SIGNAL
Error 24 - INTAKE AIR TEMPERATURE SENSOR SIGNAL

At this point I got all excited and thought it was a simple case of swapping over the 2 black wires on my centre plug which correspond to these two; alas sadly this made no difference. Will give it some thought and come back to it tomorrow.

Thanks again for all the helpful advice. Any other tips are welcome.

[tiff_lee]

Why was the loom cut originally? is that the original ecu then?

I would line check (multimeter on continuity/ohms) from those 2 sensors to the respective wires at the ecu.

What revision/market ecu is that as the pin outs seem to vary.

[b8ucks]

Thanks for the tips. Wiring is now sorted thanks to a decent multimeter.

Error codes have now cleared as well which is a good sign.

Sadly the car is still running really rough. It ticks over, but smells very rich and doesn't idle nicely or rev cleanly. I changed the injectors and turbo before rewiring the ECU so I wonder if something has been put back incorrectly. I'm left scratching my head a little bit.

The most obvious thing would be that maybe the injectors were wired in the wrong order. I'll double check this when I get some light tomorrow.

I'll also change the lambda as I have a spare one and see if that improves things. Then I guess I'll check the timing and look at the ignition side of things.