hello all! this topic probably has been covered alot but i still cant find out what signals control the guage and ecm. can any explain what the signal is leaving the xmission, to the buffer then to ecm? if thats the correct order...
also, what kind of signals are they? ive heard ac at the xmission then the vss converts it to digital? then ecm reads? or vice versa?? any charts or schematics would help. i built a digital readout for the dash so i want to grab a signal from either of three (ac or dc) and convert it.
one more thing, if anyone has done their own readout, can they tell me how they did it? i have the electronics done, i just need a signal...

 

almost 4got, 2k and 4k, is that 2000 pulse per minute or mile? is it linear ??
meaning, if im going 30 mph will the output be 60000 pulses? or is it timed pwm (pulse width modulation). like i said before , i can convert the ac or dc signal to digital.

 

In what application? The '85/700r4 in your profile?

If so, it's cable driven to the speedometer, and there's a sine-wave generator in the back that sends the signal to the ECM.