... or am I just on crack? I have been using both TunerPro, and Tuner cat. How is it possible, that taking "X" .bin file and loading it into each, can come up with different results for a given item? Isn't "Y" location in the bin, what it is, and that's that? Example: I load up "X", and set the EGR enable value to 255* in tunercat. Then load the same .bin into Tunerpro and get something like 100*! (example values only) Some things are stable, some aren't. What gives? Have I been sitting in the sun too long?

What your probably seeing is the conversion values. Within the prom, all the calibration constants are stored as raw hex, and need to be converted to be human friendly. This means multiplying by some number, adding an offset, dividing by a scalar, etc. Sometimes the correct conversion isn't used, so in that case, you would see different values for the same thing. The hex value in the bin didnt change, its just displaying differently.

For example, say there is an RPM threshold to enable the EGR. We'll say its 1500 RPM. The ECM stores this RPM as RPM/25. In this case, the value stored in the bin is decimal 60, or $3C in hex. If the person who composed the XDF or TDF uses the wrong conversion factor, you will see something different. Say by mistake the conversion used was RPM = value x 10 instead of the correct RPM = value x 25. In this case when you open it in the other program, you will see 600 RPM instead of 1500 RPM for the EGR enable threshold. The value didint change, just that its not displaying correctly.

You would need to look at the conversion factors in the XDF or TDF to see which is correct, but this means intimate knowledge of the ECM that it was written for.

Everything Dimented said... To take the wrong conversion a step further, in the '7747 many of the CTS values are in raw ADC counts. To convert these a lookup table is required. The EGR enable temperature is one of these parameters.

In the '7747 there is also a linear -5 to 135 *C variable. So it is easy for the ECU creator to use the linear conversion for all of the CTS based parameters. While not realizing that there is really two separate CTS conversions. This is one of the '7747 idiosyncrasies that I hated.

Best bet is to change the conversion in the ECU/XDF so that the raw value is displayed (no change). Then use the lookup table from the hac to do the conversion manually. Note that this raw value is inverted, a value of 0 is 200C, while a value of 255 is -40C.

RBob.

And yet another nail in the coffin for the stock 7747... I've already emailed you on shipping rates for an EBL.

Thanks as usual to all you guys.