testing vss in L

stamp_licker · Post by **stamp_licker** » Tue Aug 22, 2006 7:56 pm

anyone had any luck testing the vss in a L?hooked upa multi meter to the plug at the ecu,pin 29, turned on the ign spun the speedo cable nothing.i may have the wrong pin the only aus pinouts i got r 3 plug mines a 4 plug which i havethe american pinouts should be the same.

Chris_Rogers · Post by **Chris_Rogers** » Tue Aug 22, 2006 8:43 pm

what cluster? I have my 4 gauge dash one here with dash harness so I can look at it andr tell you.

I also have a early 3 pin ECU harness here too. is yours early or late?

stamp_licker · Post by **stamp_licker** » Tue Aug 22, 2006 8:58 pm

its the standard cluster temp fuel speedo tach.its a4 plug ecu.i'm looking for the pin at the plug ecu end.from the dia grams i've got i don't think it matters which cluster you've got as long as it a late model ecu .Ta

Chris_Rogers · Post by **Chris_Rogers** » Tue Aug 22, 2006 9:18 pm

give me a bit and I'll trace it.

Chris_Rogers · Post by **Chris_Rogers** » Tue Aug 22, 2006 9:28 pm

according to mine (dash side) its a grn/yel. should be able to find that at teh ECU. I looked at my cluster (ECU harness is removed from the actual harness.) for that so you should be able to find it at teh ECU as well.

Gannon · Post by **Gannon** » Tue Aug 22, 2006 9:42 pm

How have you been testing it?
You should be checking for continunity between pin 29 and the chassis?
The reed switch basically shorts pin 29 of the ecu to earth.

BTW im not doubting your electrical ability, just ruling out a possiability.

vincentvega · Post by **vincentvega** » Wed Aug 23, 2006 11:07 am

posty your not going to be able to see it on your multimeter. its switched to ground each time its pulsed, but you have nothing pulling it up to a higher voltage again so your not going to see anythng.

if you really want to see it, grab a 10K resistor and connect one end to your sensor wire, and the other to 12V somwhere. You will then see a 12V square wave coming out of your sensor.

I am assuming you have a decent meter that does frequency, switch it to that setting and you should be able to see a varying frequency with speed.

To really see whats going on though, you really need to use an oscilloscope. I can bring one to a club meeting or something if you like

by the way - the 10K thing is only needed if your testing the sensor on its own, if its stil plugged into your ECU then the ECU will pull the sensor up

stamp_licker · Post by **stamp_licker** » Wed Aug 23, 2006 3:43 pm

all i want to work out is if i,ve got the right pin,29 is what i have been looking at but mine is yellow red wire and man says grn yel .the way it operates is the same as a lib volt wise.i need this to make the auto shift properly and don't really want to put a lib cluster in if the l one will run it.Dane i will bring it to this months meeting. Thanks

Chris_Rogers · Post by **Chris_Rogers** » Wed Aug 23, 2006 5:42 pm

I see what you are doing. grab it off the cluster- easier.

stamp_licker · Post by **stamp_licker** » Wed Aug 23, 2006 6:53 pm

Chris_Rogers wrote:I see what you are doing. grab it off the cluster- easier.

yep the way i'm going to run my box is with one sensor connected to both tcu inputs as the centre diff will be activated by a switch. if you want it to run properly you need the one on the back of the box and the one on the cluster,something i might look at doing later but then i'll need a wrex tcu.if the car was a manual you can get away without it.also vdo makes something that'll work for vss if you got dollars to burn.