424 11p Park Nuetral Switch?

[h4x0r]

304 Running 424 11p & Trimatic auto.

I am having trouble with the idle tune when I switch from park/neutral to reverse or drive. Sometimes it can stall. Do I need to set a park/nuetral switch? if so how? what settings should I put in 11p to use a trimatic?

This is my wiring: viewtopic.php?f=32&t=1352&start=0

[Jayme]

you have two options... the dodgy way is to frig with idle settings to make it not stall... one way to do that is to bring up stall saver rpm so that if it goes under say 600 rpm it adds 20 steps immediately and stops it from stalling.

the correct way is to hook up a park/n switch, because the PCM has 2 seaprate memories for the idle speed.. in gear vs out of gear. if you hook up the p/n switch, when you put the stick in gear the pcm will immediately add the nessesary steps to maintain idle speed in gear.

[h4x0r]

How do I wire up a Park Neutral Switch on a 424?
If you look at the link for the 424 wiring I don't see an obvious park neutral switch like I do on the 808

[Jayme]

you may have made it harder for yourself using a 424.... they must do the idle logic from the range switches...
here is a chart.

Transmission-Fluid-Pressure-Switch-Assembly.jpg (52.8 KiB) Viewed 3205 times

so Mayyyyyyybe you can fudge it? might be worth experimenting. based on the diagrams, I suspect the PCM has internal pullup resistors... so a disconnected wire would show 12v on that circuit. so it 'should' show D2 at the moment. if you earth D2, it should show P/N on the ADX logging, then let go should be D2. so you may be able to use that to control the idle??

[h4x0r]

So far I have 12 volts being measured on these 3 pins:


Which matches your prediction. Only problem is TunerPro isn't displaying any transmission data....? It doesn't even display D2, nothing is set. Do I need something wired or programmed to allow automatic transmission data?

[Jayme]

my only theory at the moment is that its erroring/bugging out since at keyon there is no oil pressure in the gearbox to trigger any switches, so at keyon, Range sw B would be earthed. maybe try earthing range switch B at keyon then see if the ADX behaves?

[h4x0r]

I spent today playing with the pins on the transmission pass thru plug. But still nothing. I tested the Economy/Power switch and it doesn't even signal any changes in tunerpro. It's like nothing from B1 to B12 on the pcm plug is doing anything.

[h4x0r]

OMG ITS WORKING

So to get B1 econ/power switch working you need to set both flags in the general settings.. Not relevant to the pn switch but a follow up.

I got the transmission data working by re-downloading the adx file. I must of fooked up a setting sometime in the past. After that the transmission data lit up like a xmas tree

You were spot on Jayme. Without the auto pass thru plug connected it shows Drive 2. You just need to ground each range switch (B2, B3 & B4) to change gear selection. I owe you a beer

Hopefully I can solve my idle tune when selecting in and out of park/neutral now.

[Holden202T]

yeah i had to use a bit of a relay switching combination of pins to get the 424 to work properly with the hydraulic T700