no gear changes..stays in first.VSS ISSUE.Thoughts please

[zen]

hi..getting there..slowly..i must admit i dont fully understand all parameters yet, but i am trying...i have searched and re re re read manuals..i expect i made a silly mistake...this is on the car..not bench..

ms2x ecu talkng to megashift..controlling zf24 hp eh box..(4 speed)i am using setup as 4l60, not using sol3 just sol a and b to control gearchanges.
pwm on pc solenoid and on/off for tc.
pc is working fine..
reverse is working fine..
speed input is noisey..i will be dealing with that i hope tomorrow..(see below)
my speed crt from box using zf box is twin wire..vvs input is + and - with a shield..i have connected + to vss in and both - and shield to gnd..any suggestions?

but the main issue i have is the megashift just stays in 1st gear..it will jump into 2nd but changes straight back to 1st..the gauge on TS dash indicates
its in first..its NOT i think a wiring issue with solenoids..its only 2 wires after all, and it does sometimes try to change into 2nd.(but changes stright back to first)
the speed readout. though noisey is roughly accurate so the gearchange table is working and shows it should be 2nd, 3rd etc..but no still in first..

i have the paddle shift inputs not connected..and also brake,led outputs.table switch is turned off (says default table 1)

i enclose msq if anyone could cast an eye over please..i know you wont be familiar with zf box, but its the settings in TS in am after checking if you dont mind..

PLEASE dont panic about table 1..it was as table 2 but was playing with to make it change up earlier..it made no difference whatever i put in it..also dont worry about engine msq, thats in progress(car only been legal a day or two)

thanks simon..

[zen]

I was wondering
Would dirty vss cause this due to hysterisis on gear change etc?

[Ap67et10]

I found that VSS can cause all kinds of problems. No shift is one of them. It looks like you uploaded the MS2 tune, not the GPIO tune. Do you have a datalog you upload also?


Andrew

[zen]

anyway..got gear changes now..it is the vss signal...ZF24HPeh gearbox..USING OE gearbox wiring loom with plug and play socket cut from old oe gearbox ecu..
oe ecu is bosch..

my speed reading on ts jumps up to 100mph almost immediatly.but once up to 30 or so starts to stabilse..(kinda)

i have gpio earths tied directly to gearbox.except for pin 17, which is vss earth AND serial data link earth..PROBLEM??

have set vss masking to 85%.no change.
have altered error resets,,no change.
have altered min speed in vss setup..no change..
pwm diode is installed..
have altered resistance on vss circuit, all that did was give me no speed reading till 10mph..
tried earthing here and ther, just makes things worse..

so am left with changing vss crt to schmitt crt...though am not so sure that will work??
toying with idea of gutting out the oe loom and running screened cable directly to gpio, but then i lose "plugging in oe ecu if it fecks up capability"..the oe loom has engine signals sent to it..ie tps,tacho etc..though they are not connected to gpio..would rather not gut loom, but if i have to i will..

is there an aftermarket/alternative vss conditioning crt/board available??

if all else fails thinking of using car speedo output. which is from cable operated pulse generator (i think reed switch)..4 pulses per cable revolution driven from gearbox speedo cable..but as this is not standard on my car (it is from 1992 onwards and my car is 1971) it would mean i lose my mechanical speedo and would have to get rather creative to get a working speedo in my 40 odd yr old instrument cluster..

oh car is very very early range rover with 4.6 supercharged nitrosed v8..

any thoughts please, and thanks for your support ,,simon

[Addicted]

Are you in a position to scope the signal from the VSS?

I assume it was working fine with oe tcu?

[zen]

Yes it was working fine with oe controller

And yes i can scope vss signal

Re vss wiring..it runs a pair of wires marked vss+
And vss-
Both are screened..i have connected vss+ to gpio vss
In and vss- to earth on pin 17 .the screen is on another earth
.would it help to put screen on pin17 as well??

Have ordered lm2907

Thanks

[Addicted]

I know with my own VR sensors I have the screen grounded seperatly... in fact my Audi loom connects it to a chassis ground close to TCU.

[zen]

this is starting to hurt my head now..no speedo reading till 3ish mph, then reads 100mph!..though if i put transferbox in neutral and allow to drive reads ok*(ish)

so decided to do away with Range rover gearbox loom and plug and play setup..i will be using the loom but gutting it to just the essentials and hard wiring straight to gpio socket.
i will be building the lm2907 crt, in a screened box hard wirinng vss cables into it,.
i may even do away with gearbox vss and use external (speedo)cable driven pulse generator from speedo output...(already installed , 4 pulses per cable rev..8000ish per mile), though this means getting bespoke cable made from pulse generator to speedo head.

the ign feed into gpio is quite clean, though i will be adding large capacitor and any other noise filtering i can think of..

other than above i cant think of anything else to try...this thing shows soooo much promisse that i can't give up and reuse the sooo crap oe ecu...
thing is i move house in a week!!!and need to drive car to new place, not trailer!!

[Bernard Fife]

zen,

Have you tried any of the tips here: http://www.msgpio.com/manuals/mshift/vss.html ? If you haven't tried them, you should. If you have tried them, which ones? And what results did you get (ideally with datalogs)?

Lance.

[zen]

hi Lance

well today i spent 8 hrs on it...and only made things worse

i have tried everything on said page you mentioned except the schmit input trigger mod..however i built a circuit around the LM2907 and optocoupler..
all that did was crash the gpio!!yes it gave a nice square wave out, but even when car staionary speedo was reading 44mph!..there appears to be a tiny pulse on the output with that circuit , even if the engine is not running...gets worse if i apply the brakes...
yes i have no idea what is causing this...so thats now removed...it wouldnt even allow me to engage reverse!

i have tried so far..(JUST USING gpio crt no lm2907)..complete rewireing of gearbox loom..(ie now just the essentials).vss is twin screened cable, vss- and screen earthed at pin 17.(using OE cable)
running power directly from battery.
altering gpio resistances to make less sensitive.
altering all vss software settings, one at a time and also all at once..
pwm circuits are diode protected.
car is 1971..there are no noise sourese except gpio and ms2..alternator has been disconnected just in case too..
i have tried resistance is series with vss and also in parallel..

everything i have tried has made vss crt imoperative or worse...I WILL try schmit drt mods on gpio..nothing to lose..

next is either fire..or doing away with gearbox vss and using speedo transducer run from cable speedo drive from transfer box ..though this means i will lose the oe speedo..which is bad, cos i would like a speedo..have to get this sorted, moving in less than a week and need to have car mobile..
simon