Anyone worked with the 16196397 yet?

[Xnke]

It's funny you mention the PROM size, as both my 4347 and 6397 have 256K chips fitted to the board. What's limiting the program size?

Yes, the widebands I am familiar with will drive a 5mA load, but I generally try not to ask much of the sensors I can't control-with so many wideband controllers out there, some of them may not drive a 5mA sink.

I'll do a little more digging around on the board before I close up the 6397 case, make sure things are working the way I'd need them to and confirm with you that A28 is a viable input for a wideband logging input.

EDIT: It looks like on the 6397, at least in a main-power-off state, that a 0-5V input results in a 0.9 to 1.5v change on pin AD4 on the E-side MCU. That's good enough for me, I believe that logging and reporting the voltage on that pin could be used to monitor AFR. Is there enough room left in the program to log 0 to 255ADC count as a linear 10.0 to 20.0 AFR? That would work out as a simple 0-5V wideband input, usable by most brands of WB02 controller out there.

[RobertISaar]

address pin 15 could be brought over to the PROM pretty easily, but then 2 other obstacles are left: flashing program would need changed to account for a 64KB PROM on at least the T-side and then would need to make sure that the aux chips that the T-side accesses over the parallel address/data bus wouldn't be effectively disabled with the new PROM's addressing space. logic gates/address decoders would probably be ideal here, I can't remember how much control the 6811 has over its CS circuits.... probably not enough to do it through code alone.

that's really about it.

[RobertISaar]

EDIT: It looks like on the 6397, at least in a main-power-off state, that a 0-5V input results in a 0.9 to 1.5v change on pin AD4 on the E-side MCU.

you might need to elaborate a bit here... are you saying minimum voltage achieved was .9 and maximum was 1.5?



also, did some simulating of the MAP sensor, I see why the ECM uses a 51K pulldown for them now... other values cause the sensor linearity to suffer. with a 1K pulldown, it was rather interesting charting out pot position vs what the a/d converter saw.

[RobertISaar]

playing with the sim, assuming a 3-terminal sensor(essentially a pot), if the pulldown resistance actually has a HUGE effect on the signal the a/d converter sees. using a 5K pot with 5 volt reference with a 5K pulldown, center voltage is 2.0.

with a 10K pulldown, 2.22 volts.
20K pulldown: 2.35
50K: 2.44
100K: 2.47
200K: 2.48
300K: 2.49

to get back to 2.50 volts(rounding to the 1/100ths digit): you need to use a 624K(or greater) pulldown.

considering the a/d converter has a resolution of ~.02 volts, that 200K pulldown is pretty safe. response at the a/d converter is extremely linear everywhere through the range as well.

now, this was with a sensor that has 5K of impedance end to end. with a 1K pot, the same trend of needing a pulldown with 40 times the impedance of the sensor itself to keep with .02 volts of accurate through the full range seems to work here as well.

[RobertISaar]

alright, got a VERY clean looking 6397 coming in from California for $13.97/shipped. they even included a picture of the p/n sticker, has a BPJH calibration though I don't have a cross-reference for what that could be(and the lower/tearaway half of the sticker is gone), have to pull communicate with it over ALDL and check the part number that way.

[Xnke]

I know that BKRK is the 3100 Beretta Manual Trans, and BNFM is 3.4L Camaro Automatic, but BPJH I am not sure of. Possibly 3.4L Camaro Manual.

Yes, that's what I meant about the 0.9 to 1.5v range-I was using an adjustable bench supply, but the ECU was NOT powered up.

Looking at the result you had with the simulation, I am rethinking just closing up the case. Looks like I'll have to hunt down that 1K resistor and remove it, then fit a 200K or 470K resistor (I am pretty sure I have some SMT 470K's laying around...somewhere...)

[RobertISaar]

beretta manual? I have most if not all of the calibrations GM released for this whole lineup of PCMs, but there was never a manual 3100 anything released in the US.

with a .6 volt range, you would have roughly 30 a/d counts to work with. that would be pretty rough, considering that's a little worse than what a 5-bit A/D converter would produce.

if you really wanted to.... you could always lift the pin off of the board and setup your own filter/pulldown rather than attempt to hunt down the existing components. at this point, there isn't going to be a huge difference in the amount of work/risk required.

[Xnke]

Ohhh, the things that this computer can do provided that a bigger PROM space is workable...

Digging through things, I *think* I see all the hardware needed to drive a Bosch LSU4.2 wideband O2 sensor, although it would make better sense to just interface a Bosch CJ125 Wideband Controller chip and run the new super-cool LSU4.9 sensor.

[Xnke]

Yes, beretta manual. I pulled it myself, was a 1994 Beretta, manual transmission, 6397 computer. Had 3100SFI across the upper intake manifold, as far as I can tell it was "stock" but it could have been a swap.

I'll just lift the pin and put a proper interface on it, 10K isolation with a 470K pulldown resistor, if I can't hunt down the 1K pulldown that's in there. Lifting the pin would likely be easier...

I'm almost done with the intake port work, the exhausts won't need hardly anything. After that, the heads/intake/accessories get bolted up and the accessory drive gets finished...I am gonna need an idler for the power steering bracket, belt wrap over the supercharger is less than ideal and belt wrap around the power steering pump is laughable without an added idler.

[Xnke]

I am just now realizing that while I have a good handle on the 3.4L camaro harness wiring, I know next to nothing about how my pickup is wired...or what the dash sensors need to see.

Anyone got some thoughts on which parts of the truck harness absolutely have to stay? I'm gonna be un-looming the whole engine bay harness, removing the engine control wiring, leaving the alternator/starter wiring in place, and the dash gauge wiring will stay in place. I have NO IDEA where most of that wiring is at yet-basically I'll strip the whole forward assembly down to the frame, removing everything from the firewall forward, pressure-washing the frame and scrubbing it clean, then I'll start un-wiring the engine harness from the body.

I'd like to use the original dash wiring if I can-but there really can't be that much wiring in this old truck. The dash wiring in my Datto wasn't bad at all...