Map sensor supply

[Denmark]

Hi All.

I have been having a problem with the subaru´s when using the oe Mapsensor, as i cant scale it in, becource i cant slope it enought to get in to show the real data in megatune,
I have since found out that i only got 4.82volt at the sensor, and that on all the subaru´s were i have used the oe sensor,
so i suspect that the vems have a 5volt supply that is to weak,
have any of you guys had a problem like that?

Thanks,
Skassa

[lugnuts]

Are you using Pin 28 (5v Supply) or 29(TPS Supply)?

Pin 29 (TPS Supply) is weaker, I have run into this problem when supplying a TPS and a Baro sensor together, the TPS was off.

[Denmark]

It is when using the 5volt supply, and TPS is feed direct from the TPS supply.

I´m thinking that maybe they more thing connected in the Subaru wiring, and the oe 5v supply is stronger,


/Skassa

[GintsK]

It is when using the 5volt supply, and TPS is feed direct from the TPS supply.

I´m thinking that maybe they more thing connected in the Subaru wiring, and the oe 5v supply is stronger,


/Skassa

Can you measure current in both 5V?

[Denmark]

I have just in the process to make a few more Vems ecu for Impreza´s, and i have just notised that there is no 5volt supply  from the oe ecu seperate to the mapsensor,
there is only one 5v supply from the ecu, and that goes to both TPS and MAPsensor,and that is probbely why i always had mapsensor problemswith the vems ecu,
Can i make just one , 1amp supply, and use that instead of the weak 100mamp that is installed on the vems ?

thanks,
Skassa

[GintsK]

What pin from EC36 you use?
If you take 5V for mentioned components from pin 29 (BTW with confusing name in documentation) - it is normal to get voltage drop.
For your OE harness EC36-28 is right pin for common 5V.

Pin 29 is supplied from 28 trough 270Ohm resistor inside ecu. It is for some full-proof when TPS is wired wrongly.

Gints

[Denmark]

Jep, i have just found out, it's a 270ohm, that's also why i miss some voltage and only measure 4.8v at the mapsensor plug

thanks
Skassa