1994 F body pcm for 1996 Y body obd II to obd I conversion?

[Lockdun1]

Sweet I got my 051 pcm for free and did the resistor mod today for the knock sensors. I started with a 95 ybody bin the copy pasted timing/ fuel tables from the tune I got from from stevos tool on fbodytech, deleted vats/egr/air and made sure the vette maf cal was patched in. Should be ready to go when my aldl gets here.
Ok that’s very good to here that both of you seem to have had good look with the trans working fine. I hope mine does to.
I’m trying to decide what I want to use to flash with I hear eehack can be hit or miss with bricking but it does have that silence Orion for the y body. I can just get get cats it’s no issue. What do you guys think?

[steveo]

if your serial connection to the ECM is stable, eehack's tool should work fine, people have done lots of flash writes with it without issues.. but cats winflash is definitely more well tested, and commercially supported. if my free flash tool bricks your ECM you're on your own. no tool will save you from an unreliable serial connection.

[lionelhutz]

I'm pretty sure if CATS software bricks it you're on your own too. Use EEhack and just make sure the battery voltage is good and the comms are stable.

[steveo]

I'm pretty sure if CATS software bricks it you're on your own too.

he does offer a repair service, last i checked (i think he built himself an in-place bench reflashing thinger)

[steveo]

its also worth mentioning that one advantage to eehack's flash write is that it's designed to write less packets. it remembers your last bin write and only flashes the half of the ECM you've changed, and it doesn't write anything to areas of the bin that the ECM doesn't actually look at.

technically this should make it safer, but i think tunercat's tool is still more mature. he probably understand's EE's code better, and does this for a living, while i'm just a nerd who wanted to prove that i could write a flash tool that works.

[Lockdun1]

I’ve been wanting to use eehack since last year but I had to sell that project. I believe that it is the way to go and a lot of folks seem to think so as well. I hear there are things you can do to help make it safer. Like unplugging the fans and such that cycle during the flash. I’m going to run a charger on the car and use my mini desktop for the tuning that will be plugged into the wall.

[Lockdun1]

Well the day kinda ended in disappointment my red river cable will only work with 94/95 scan program as of now. Winflash or eehack just won’t communicate with the 94 pcm. I tried everything tried different windows compatibility whe whole deal. Reinstalled drivers and all kinds of stuff. Short of making a bench set up idk what else to try.

[Lockdun1]

Success! Started pulling fuses and the airbag/ccm ones did it. Specifically the ccm 3 is the one that does it. Well anyways she worked! Eehack kicks ass. I noticed I have a code 43 so I guess my solder mod for the knock sensor didn’t work, I’m goin to take it out of the ecu and try it in line. I’m getting a code 96 as well from the trans so I know I’m going to need to do the valve body but I’m very happy right now! Everything will come together soon.

[Lockdun1]

Well my Speedo hasn’t worked really since a week after I got the car. Dash just reads full values for everything needs to be repaired.I put original pcm in I get no vss fault at all it’s only with the obd I one so I’m assuming it’s simething to do with ccm but idk. I’ll look at a pinout and see if I can inspect the wire. The fault may be from me pulling the ccm fuses while datalogging and the wire gets no resistance while it’s unplugged ya know .

[kur4o]

The ccm drives the digital display on the dash, so it is likely to not work when you pull the fuse.
I suggest you make an idle traffic log with obd1 pcm and with the obd2 pcm and post it. I will see what is exchanged and can the obd1 pcm be hacked, to send the same data format.

The vss should work, but I noticed that sensor pins are reversed. On 95 pin a goes to low, and pin b goes to high. On 96 pin a goes to high and pin b goes to low. The wires color coding is the same though.
As a last resort you can switch the pins on the vss connector.

EDIT
I just realized that the code is for the vss output signal.

The wire goes to ccm, cruise, radio and real time damping module, so it is not clear what happens with the signal when you turn the ccm off.

[Lockdun1]

Without it plugged I don’t think it gets the signal resistance is needs and since I can’t datalog properly with it hooked up testing what the problem is well.... problematic. I’m pretty sure it’s that though when I first hook up the cable and pull the fuses it’s not shooting the code it only comes on later after they have been out for a bit . I have the new knock sensor in hand but it decided to rain today so getting to my buddy’s shop isn’t happening. Hopefully sometime this week and then it’ll be perfect. Afr is good ,Timing was dumbed down for 91 octane and I’m running 93 so even without me letting it pull timing at the moment it should be fine.

[lionelhutz]

I zero'd out all the knock retard stuff on my engine. With the roller rockers and headers it was retarding the timing to the max almost any time the pedal was being pushed.

From my understanding, the only way to change when knock is detected is by changing the knock filter. There are claims the knock detection can be tuned, but it's really just tuning how fast it retards timing and how much it retards timing. I didn't see anything for the thresholds of knock or anything like that.

No-one knows what's inside the knock filters and the LT4 filters are stupidly priced these days. I'm sure it could be possible to reverse engineer the filter since it's likely a passive component filter, but I can't be bothered. I tuned it fairly safely and am aggressive with the transmission so it doesn't lug the engine to reduce the chances of actually having knock.

[Lockdun1]

Sweet I have em tuned out still. What I will say it was cutting out on me before the swap at random places at wot before and still was with the new pcm so I had a look in the tank and it was fubar ,someone must have not liked the P.O. because the tank has crap in it that is not rust. Tank surface is clean but there was a lot of black powdery junk that had to have been put in. I need a new pump and another filter. I changed the injectors and filter when I got is because they were jacked up. Something corroded the filter and it had come apart on the inside. Maybe it’s filter elemaent idk but I need a new pump and to clean the system before I can do anything else.