map sensor scaling

[Snake4309]

Hi. Wondered if anyone could assist scaling GM 3 bar sensor.
I have used settings I found online and also calculated myself.
I believe the sensor displays absolute pressure.
In my case 9psi at idle.

Is there a way for show - value in vacuum?

I have seen videos from other users doing this successfully.

I did read to subtract 1.00 from 'b'
But doesn't seem to have made a difference

[ArT]

Hello.

I sent you mail reply 2 days ago for this case. I'm quoting it here:

Please send me output table for this sensor, I'll need two values correlated with pressure (bar) for 0V (or 0.5V) and for 5V (or 4.5V).

On screen is 1.62V = 0PSI (0 BAR) and 5V = 28PSI (1.93 BAR) which should give:

a = 0.57 and b = -0,93 <---- it's for absolute pressure, b is with minus. If you would like to deduct 1atm pressure, b should be +0.07, so:
a = 0.57 and b = +0.07

Scaling is always in BAR, but displayed unit can be in PSI.

[Snake4309]

Hey..

I apologise, maybe junk filter caught your email as can't see it. Thanks for your efforts, I do appreciate it.

I'm sure your correct with what you have written is correct.
I clearly misunderstood the - 1 bar part..

Once I have daylight here. I shall upload and see how it goes. Hopefully all will be well. I shall update you and upload voltage table if required.

Thanks.
Jake

[Snake4309]

Well to update. I believe map sensor is faulty. It seemed to work briefly displaying vacuum. then next time ran the car displayed some figures that definitely weren't correct.
So have ordered a Bosch Motorsport sensor to try instead.