Configuration Resistors on 3VZ-FE ECU

[jon.sole]

Hi,

Has anyone played around with the configuration resistors on the 3VZ-FE ECU circuit board? I haven't seen any information on the internet, so I thought I'd post what I've learnt so far...

On the back of the PCB with the CPUs on, there are 3 resistors that look like they are used to configure the behaviour of the ECU, in the photo below the resistors are marked in red (position of the fuel/ignition CPU marked in yellow).



Toyota made a number of variants of the 3VZ-FE ECU (M/T, A/T, EGR, non-EGR), I reckon that these resistors are used to enable/disable certain features.

What are these features? To be honest, I don't know for sure, but I was bored at lunchtime and had a play around.

Moving R753 over to R754 didn't seem to have much effect :icon_conf, maybe it disables EGR?

Undeterred, I reverted the change and tried moving R752 over to R751. Now this one did have an effect :hehe: Taking into account that the 3VZ-FE is still in a Camry, I noticed that the idle now drops when drive or reverse is selected. Before the ECU would compensate for the additional load of the auto box, the idle would stay at 750rpm before the resistor change, now it drops to 500rpm. Also gears changes by the auto box are harsher, as if the ECU isn't bothering to retard the timing when the auto box changes gear!

Could this be the key to getting the ECU working with the manual gear box?
Unfortunately I don't have a V6 MR2 to test the idea, any one up for giving it a go?

The 7M-GE ECU can also be configured by modifying some resistors, for anyone interested, pop over to http://www.supramania.com/forums/showthread.php?t=73379, the guys there have been reverse engineering the ECU.

Cheers,
Jon