Syvecs Forums

I've been told that the'05 JDM STi has an air temp sensor mounted on the underside of the plenum, wired to the ecu, but only used by the group N ROM.

Rather than plumb in a new IAT sensor to the FMIC pipewwork and connect it to the old temp sensor wiring for the MAF, it seems to make sense to make use of this sensor.

Does anyone know the pinout of the '05 JDM STi (believed to be the same as the '05 UK STi) so I can trace the wiring through and make use of it? Specifically I need to know the pins for the MAF temp sensor as well as the plenum-mounted sensor.

OK - found a wiring diagram and it looks like ECU pin "D6" is for the intake temperature sensor. Can anyone confirm which of the MAF pins is the temperature sensor pins - then I can try swapping them at the Syvecs connector and seeing if it works

And are the ECU pins easy to identify?

Tim,

If you look here you'll see the pin that the MAF ACT enters the ECU at is B27. Would suggest moving the pin from "D6" over to B27... please note that the connector letters may not be the same between your wiring diagram and the one here... make sure you get the right connector!

Cheers,

Pat.

Thanks Pat

Finally got around to doing this.

I buzzed the sensor wire back to pin E14 at the ECU, but I don't have a proper pin extractor for the connectors and although I tried with a very small jewellers scredriver I gave up for fear of damaging things. In the end I cut the wires in the engine bay and connected the MAF temperature sensor wire to the plenum sensor...and all seems to be good

But, for '05 JDM STi's it might be worth changing the PnP wiring to make use of the oem inlet temperature sensor?

FYI, when I refer to connector E, I mean E as per subaru workshop manual which looks like the connector below - I think you call this connector A?

Tim,

Thanks for the heads up on the pin location for the stock ACT sensor, if nothing else we can provide instructions for which pin to move! If memory serves there is a pin lock on the MY099 and later plugs that needs to be removed before the pins can be extracted, whilst it was obviously present on the MY99-00 plugs (it is a different colour), I seem to recall that the one on the MY01- is the same colour and not obvious.

With regard to changing the PnP carrier board to allow the OEM sensor to be used, that's non-trivial and the fact that a simple pin swap will achieve the same goal means it is unlikely that we'll re-route the board and produce new Artwork for the PCB.... if we'de got something major "wrong" (like getting the wrong pin for the crank and hence no way of getting that in without moving a pin) then it'de be a no-brainer to redo the carrier, but as it stands it is a minority of cars that actually have the sensor...

Cheers,

Pat.