Anyone worked with the 16196397 yet?

[Xnke]

That's the weird part-it happens at exactly 50kpA manifold pressure. I can simulate driving by using a trigger wheel simulator and operate the MAP sensor with a hand operated vacuum pump-the PCM will kick the AC compressor clutch off at 50kpa. If I pull a little more vacuum, the clutch will lock back in again.

As far as all the files, all the current patch code is included in the XDF, as well as what it replaced. To patch the bin, Start with the Rev3.01 patch, then the 2-bar patch, the wideband patch, and the fuel injector voltage patch, in that order. That's exactly what I have running in the truck now-I haven't changed them in months.

There is an N/V ratio to consider the truck at WOT and disable the A/C, but it doesn't seem to matter what I set it up to, the 50kpa switch point stays the same.

[kur4o]

I think I found the cure. It matches exactly the symptoms 36 mph and 50kp.
There is one byte changed at the spi comm that is used in ac routine.

Change 819d to ff and 819c to ff.

[Xnke]

Nice! I'll look at that tonight, and I'll post the segment of code I think you mean to make sure I understand what you're saying.

You're saying:

On the T-Side, change the SPI communication byte that is part of the A/C on-off routine, at location 819D from whatever it currently is to FF, and at 819C from whatever it currently is, to FF.

[kur4o]

Patch reconfigures one of the SPI comm byte that is used in ac routine. This byte is compared with 819d and 819c. Stock settings are $24 and $80.
$24=36 and is really close to the MPH you reported. $80 might be considered 50kp. Still not clear how one byte value will be responsible to mph and map at the same time. There might be some bugs in the SPi side of the patch.

Change these two bytes to ff and report result. If it doesn`t work I wll look deeper in the code

[Xnke]

The patch changes the MAP value from 1 bar to 2 bar-so what originally would have been a 100kpA value, is now a 50kpA value. That could explain half of it-the other half, I do not know.

Basically, the T-side does the MAP analog conversion to digital, keeps the baro value, and sends the raw map ADC value across the SPI bus to the E-side. Then E-side then takes the MAP ADC value and does the math to generate a 2-bar MAP value, and also a 1-bar emulated value to send back to the T-side for transmission control stuff-because there isn't room in the T-side to do the 2-bar MAP rework over there. (also the T-side does the inital ADC, but then sends it to the E-side for the math.)

The wideband patch just slots in the wideband ADC value to the SPI bus, and sends it to the T-side so it can be put into the normal datastream sent out to the laptop. All the ADC values and conversion is done on the E-side.

I'll give this a try tonight, and we'll see if it works tomorrow morning when I drive to work. (40 miles of highway driving, the A/C almost never works on the highway.)

[Xnke]

OK, so byte 819C is already in the XDF as the "N/V (tach/speedometer vss) ratio to use WOT Disable", and the stock F-body bin it's 36, in the stock L-body bin it's 101. Byte 819D isn't defined in the XDF yet, so what I will be doing is adding it as a new scalar, naming it "Possibly the MAP value to disable the A/C", and I will play with it to confirm if that's it or not.

[kur4o]

Did you manage to test it out? I got some other ideas too, if it wont work.