7747 $42 ECU

I enabled Highway mode and could see in the data log where the engine went open loop. I have read this shows the engine is in highway mode. The first run shows sporadic highway mode. Looking at the scalars there is one named "HiWay Max MAP". The value is 74.92 kPa. I often have about 77 to 85 kPa at 55 to 60 MPH (305 with a cam in a 5k lb FJ40). I believe that means the engine drops out of highway mode when the MAP is above 74.92 kPa. Since I am quite often above that value I decided to raise it to 90.05.

I also changed the "HiWay - MPH Enable" from 55 to 50.

I ran a test and the log shows the engine never went into highway mode. What am I missing? The above values should allow longer stints in lean cruise, shouldn't it? Do I have "HiWay Max MAP" backwards? I assumed the engine had to be running under this value for lean cruise to be available.

Steve

 

There is also a coolant threshold for highway mode.

The actual MAP value needs to be below the threshold, so that is OK.

RBob.

 

Thanks for the reply RBob. The temp threshold is 70c so that shouldn't be a factor. I think a 90 MAP threshold might be too extreme so I plan to move it back to 80.



P.S. Attached is my current bin with the MAP threshold at 80. Need to datalog it.

 

I looked at my last bin and the hiway patch showed an indeterminate status. I figured something corrupted. I started over and it is working again.