Hello,

I have designed my own OBD reader, and have greatfully used the sources found here (many thanks Florian ). It is a miniature version, to be build in the dashboard. More info can be found here, it is in dutch however, sorry for that.

My OBD reader will be used in my lupo 3L and is for 99% finished now.
I can read all measuring blocks from my ECU, there is one read value however which troubles me now, the 3rd value of measure block 5

Measure block 5 yields the starting conditions:

• 1: Engine speed = 0.2*A*B
• 2: Start injection quantity = A*B/256
• 3: Start synchronization =(B-128)*A*0.01
• 4: Temperature = 0.1*A*B

My obd reader gives 12.7 degrees but it should be within -3.. +3
Vag com yields 0.0 or 1.0
I also read the raw integer values (A=10 B=1) which means the formula is correctly processed and it seems I am using the wrong formula.

So my big question does anyone know the correct formula ?

Hello foppe,

I guess I can help you if you show us the complete answer
from the ECU if you request block 5.

best regards

Andreas