Hi everybody,
I'm back with my VW Golf running for one week all day long with my Vems 3.6,and I think i'm on the right way :D.
Now I'm on the fine tune step and going to connect all the peripheral device.
My questions today is about a very strange Tacho issue:
I've wired the Tacho output on EC36 pin 3 with a pull up resistors,when I check it with DVM, I have exactly the same signal as the original Bosch ECU give out: positive 7 volt average and +/- 30Hz at idle,frequency increasing with Rpm.
Do I miss something?
Does the ecu give ground to the dashboard/tacho by a specific wire on the original ecu harness?
Ps:when I swap the ecu and put back the Bosch motronic the tacho work very well....
Any suggestions :'(
Michele
i tapped into the tach signal in wire that normally would come from the stock wiring.. instead of the feed wire coming from stock harness into fuse block i connect pin 4 with 1k pullup to the wire going into the fuse block. i can pin it out on the CE2 block if you need me too as well, however i will have to go out and lookin my car i do not remember which plug it is. i believe it a G1 or G2 plug.
Do you have Audi A3??
no its wired like that in the VW
I've tried to wire directly the Vems p259 output to the T10 orange connector and still doesn't work....
Now i'll try to by-pass all the harness and try on the 32 pin blue dashboard connector.....
Michele.
it is on a G1 or G2 plug, (clear plugs)
i will get pin tomorrow when i can look at the bentley diagrams.
well did the pin i gave you work?
i have pullup internal on my pin4 so i just run a wire right to the pin i emailed you on the fuse block..
like that i alost every vw
I have a tacho problem to,
When engine starts it shows rpm nicely but after 10sec tacho dies.
Voltage is 12v pullup through a 510ohm resistor on the P259 tacho output
When tacho dies voltage droppes to 6.6v engine kees running nicely?????
Any ideas anyone?
cheers andré
i changed resistor to a 1k and most newer ecu's come with a 1k in it now..
it is aleast easy to try.