I installed a shiftkit into my AU yesterday, performs as it should, today I installed the other shiftkit which disables the S3 and S4 solenoid by earthing the output from the ECU, this means the S5 solenoid is also bypassed.

I used a DPDT switch and had the bottom tabs earthed through two 27ohm resistors, the middle tabs were the feed FROM the ECU and the top tabs were the feed TO the TRANS. With the shiftkit off the car is as normal and I can use the other shiftkit to change between soft and hard shifts. As soon as I turn the bypass "on" the car goes into limp home mode (3rd gear), and stays in that mode untill I turn the engine off and the bypass switch off. Also the first time I turned this bypass on the traction control light came on.

could be the type of switch

or the fatc just f**k the second kit off!

yeah i wouldn't run both kits! i had a s**t kit built into my new box and was told not uses the one i put in as it may cause issues,so would say to just pick one and stay with it!!!

What's the theory behind disabling 3 and 4?

Sorry im out of touch with shift kits

Yeah, I'd like to know that too.
Since both my cars are manual now - I'm a bit out of touch with autos.

I think you'll find that S3 and S4 still need to operate for the hydraulic sequencing of the other solenoids to operate normally, otherwise, you'll get LHM.
Even though electrically wise the ECU sees the solenoids, the pressure is not there, and that's where it all falls down.
The conventional shift kits that operate S5 work fine because all they do is vary the current flow throughput.
I haven't referred to my manuals, so this is by memory only.

The normal shiftkit is great but it still allows some slip, I want my gearbox to have a fighting chance when running boost.


[quote name='turbotrana' date='Nov 22 2004, 06:10 PM' post='189998']
To all the guys running serious mods thru their Auto trans that are having a hard time having it hold clutches and bands.

The cats out of the bag so I might as well be the first on this forum to tell everyone about it.

Disconnect S3 and S4 solenoids (somewhere close to the computer) and put a dummy load to earth, dummy load for each solenoid should be a single 27 ohm 5 watt resistor to ground, one for each wire on the computer side to stop computer going into limp.

I've been using this for a while with absolutely NO line pressure mods and it gives very hardshifting shifts. For us hardcore guys this mod is worth its weight in gold as it will save the bands and cluches in the trans. (long term consequences not exactly known at this stage, but what ever they are, the trans will still last longer than not doing it). The pussys who like soft shifts wont like it but I have also done this mod to give soft shifting on normal driving and hard on load but thats a whole lot more complicated.

Goodluck with it
[/quote]

Check the ECU codes, that should tell you which solenoids are an issue - then you can check your wiring for it.
While the other solenoids are controlled by the ECU then go to earth, the S5 is an exception in that it has an ECU wire, but goes to ign 12v on the other side.
You can increase your resistor value also (say try 50ohms), as I'd say you might find the existing ones will get pretty hot after extended operation.

thanks I'll try that

NP

ok, there was nothing wrong with my wiring diagram, it was just an earthing issue, ran my own earth and it works perfectly