1G-GTE ECU question....

**cambelt** · 14-07-2006, 11:55 PM

I saw a gen 3 one last week and it had the screw as well .
Dave

**Fattony** · 15-07-2006, 01:14 AM

ive seen this adjusting knob on vl ecus aswell, it allows you to swith the ecu into a diagnostics mode where you can read lights on teh ecu to see if the OBD has thrown any codes

**Karma Supra** · 15-07-2006, 03:36 AM

But on the supra you access diagnostics mode via the diagnostis port!

**Fattony** · 15-07-2006, 09:38 AM

Originally Posted by Karma Supra

But on the supra you access diagnostics mode via the diagnostis port!

yes thats true, but this little trim pot you have might be a way of switching the ecu into diagnostics mode so you can read if it has thrown any codes via the ecu, i had never had to do a diagnostics check on my toyota, i had a 1g in a ra23 celica so i didnt exactly have a engine check light in the dash to check if it had thrown any codes once you bridge the 2 ports in the diagnostic plugs, just thinking toyota/mines might have made it easy for you to read the codes rather than birdgeing the port

mic* · 15-07-2006, 10:19 AM

Firstly, I cant see any LED's...

And on Nissan's I dont think there is a diagnostic port under the bonnet is there? On the RB30 ECU iv played with, you turn the knob full clockwise, then back full anticlockwise with the ignition in the ON postion i think, and then note the flashing sequence of a red & a yellow LED.

It also said something about being an idle speed adjustment when not being manipulated as above for diagnosis. Im thinking its more likely something along those lines...

**Fattony** · 15-07-2006, 10:22 AM

only on the rb30 will there be the LEDs and yeh they are used for diagnostics and also used to check the fuel mixtures and to see if the ecu is also running in closed loop mode, the toyota has none of this.

The idle speed adjustment on the 1g was always done on the throttle body on my 1g

mic* · 15-07-2006, 10:37 AM

The gregory's manual for the R31 skyline had under bonnet instructions for adjusting the idle too.

It was just something i recall written on or near the knob on the ECU.

Anyway, if there is no LED's on the Toyota ECU, and you have no dash light, how would you use this knob for diagnosis?

**Fattony** · 15-07-2006, 10:40 AM

i never played with a r31 skyline i played with vl dunnydores so there might be some differnce, might also be a difference with the RB30ET not sure though. In the case of the toyota there is part of the diagnostics plug you can put a test light in and that will be able to flash to you the code its thrown, been a while since i played with it so im not sure which ports need to be bridged for it, but im sure if searched on the old forums there will be plenlty of post covering the ports

mic* · 15-07-2006, 11:55 AM

Just for interest, ive got a couple of bad pics showing the RB30 (R31/VL) ECU diagnosis / idle speed knob & LED's (black hole to the left)...

There is also an adjusting screw on the IAAV / ISCV under the bonnet...