Thread: VSS problem
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Old 06-12-2016, 08:39 AM   #1 (permalink)
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VSS problem


This is not the first time i try to solve this.. had given up, but now saw the MPGuino in the drawer again..

In my first car, a Alfa romeo 155 it worked flawless. Now in my Alfa romeo 75 I cant get a good VSS signal?.

Up until 20-40km/h MPGuino actually shows the speed, but then goes the oppesit way down to Zero beyond that speed??.


This is from the lead going directly into the MPGuino, .. I actually have no clue how to operate this handheld device, kinda blindly push buttons.. just, i can see that there actually is a signal, and that i had to put it at "5v" to get it to best fit the screen.

Any ideas?. I have seen many schematics of ways to alter the signal and etc.. But is that something I should try?.
Is the signal too strong?.

A little info: The Transducer speed sensor sits in the gearbox (gearbox in rear of car), and goes to a little box under the backseat, pulse generator/amplifier and then to the speedometer itself.

Update: Have tried to run a shielded cable directly from the pulse generator to the MPGuino, same happens.
And run test procedures on the pulse generator and transducer, all seemingly ok.

Actually the signal seems up to 12v strong in pulses.

Last edited by mirkwood; 06-12-2016 at 10:40 AM..
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