Knock sensors, ESC modules, and ECM's oh my! (My 91' C1500)

[scoob8000]

So THIS thread is what brought me to these forums.

So I just bought a 1991 C1500 truck. It's got a older style (non centerbolt heads) TBI 350 and 700R4 in it.

I'm trying to fix up a lot of hacks from the previous owner.

The ECM is a 1227747, the ESC module is a 16065711, and the knock sensor is missing, wire just hanging.

According to all the auto part websites, that ESC module doesn't seem right for a truck. Rock auto crosses it to a LXE7, but the parts list calls for a LXE6. The knock sensors KS6 and KS7 seem to coincide with the ESC's, and auto or manual tranny. Which knock sensor should I try, or should I be replacing the ESC as well?

I have two PROM's that came with the truck. "Stock" and a Hypertech Thermocrapper. For some reason, my TCC never locks up with the "stock" PROM, but it does with the Hypertech. I'm thinking it's been tinkered with as well. Also, shouldn't the knock sensor being unplugged be setting a code, because it's not. (Or can that be programmed out?)


My next purchase is going to be the Moates BURN2, take a look at the "stock" chip and compare to some of the bins posted on here.


Sorry for the long winded post, hope that makes sense to you all! :)

[EagleMark]

Sorry for the long winded post, hope that makes sense to you all! :)

No need to apologize for an informative good first post!


I think you nailed it with:

I'm trying to fix up a lot of hacks from the previous owner.

Something is wrong?

First does your CEL work? Yes it should set a code for knock sensor not working and yes it can be programmed out. There are some stock chips that do not have knock circuit in them, only ones I know of are HD applications, which would also not have TCC commands. So what is the BCC on chip?

You have the answers to knock sensor and ESC already! They must match, not sure of the outcome if they don't as I've never tried...

Check the classifieds as someone had a good deal on Burn 2 and stuff awhile back.

[scoob8000]

Thanks for the reply!

My CEL does work.

So I'm correct in thinking it doesn't matter which ESC/KS combo is installed, as long as they are a matched pair?

ACSZ 0050 is what's on my "stock" chip. When I looked it up, it looks like its for 1987/1988 1 ton truck with a manual 4 speed. That explains the ESC being from a manual too. No clue why he would of changed any of that though.

[EDIT] the Sticker on my ECM has ARJT on it (ARJT matches what my truck really is)

So that explains the TCC not working, and the knock sensor business.

So with the Burn2, does my chip (with plastic carrier piece) plug right into it or do I need some kind of adapter too?

Thanks again!

[EagleMark]

If you have an Auto trans then you should use that knock sensor and ESC. Cost can be kept to minimum with used parts, mine still work at 22 years old and 130k miles!

Stock chips are EPROM Erasable Programmable Read Only Memory problem with that is a UV light is needed to erase them, the Burn 2 will not program them. There is anceint technoligy to do this but it is not fool proof and you end up with EPROM paperweights.

EEPROM are Electrically Erasable Programmable Read-Only Memory meaning you can put them in Burn 2 and click erase, and burn 1000s of times.

Take my word on this and save the research time, let alone programming time and frustration. When your at Moates website get a G2 adapter and 27SF512 chip or 2. Adapter needs to be soldered in to ECM, it's not hard if you have soldered, Moates will also do this. There are other ways to stick a DIP socket or ZIF socket into old spot where chip was, solder a jumper wire, cut some pins off... or do it correctly with the adapter!

With your fleet of vehicles, a couple adapters and TunerPro RT software your going to be addicted in no time!

[scoob8000]

Okay I get it now. I thought the OEM chips were reusable, you need the adapter to use the newer style, reprogrammable chip.

I just found a 7747 ECM with adapter already installed with a blank 27F512 chip. Going to pick that up and a G2 and see what I can break. :)


I'm still wondering the difference between the Auto vs Manual ESC's. I wonder if the manual version is less sensitive due to gear noise. In which case, might be better with my older style motor (flat tappet cam etc).

[EagleMark]

The adapter address the issue of stock chip being 24 pin and new chip being 28 pin.

Some guys solder in a DIP socket, then slip the G2 adapter in, then add the chip and cover does not clear, which is OK. I solder the G2 straight into ECM board, add chip and cover clears.

So what's soldered in? If it's a DIP socket you can solder a wire around a few legs of a 27FS512 chip, and slide it in with no adapter. The adapter does this so no modification of chip is necessary.

[scoob8000]

It looks like a 28pin socket was soldered in where the original one went.

[Six_Shooter]

It could be a DIP socket with the addressing lines shorted, to keep a low profile. When I modify the C3 style ECMs, I solder a standard DIP socket to the daughter board, then use another DIP socket with the address lines shorted, to keep a low profile, so that the cover will be able to be re-installed. I find that the foam on the back of the cover just places some pressure on the EEPROM, to hold everything in place nicely.

What I'm getting at, is that you will need to wait until you get it, to figure out if the DIP socket is just that, a standard DIP socket, or a modified DIP socket, or EEPROM.

[EagleMark]

I saw that on eBay, lots of stuff we do here ends up for sale there. Some done right! But that auction did not say what was done? If done correctly the DIP would be modified before being soldered in, that way chips are unmodified. Can't just cut 4 legs off and solder it in...

[scoob8000]

Another update. I just installed the knock sensor that matches the ESC and threw the laptop on. It looks like it's working. I see knock at 0 before I crank and 20 or so after cranking. After a couple hot and heavy passes it's only up to 40 or so. Seems good.

Now to get some other issues straightened out.
(I can't get my base timing right, thinking the chain is stretched or the cam is off a few teeth on the chain) But thats another thread! :)

[scoob8000]

ECM is on it's way. Gonna make sure the adapter in it is kosher, then order my Burn2. Stay tuned. (get it, stay tuned? lol)

[EagleMark]

Oh that's an old joke around here...

Welcome to tuning!

That was a steal for that ECM on eBay...

[scoob8000]

Okay, I got my Burn2 and just flashed the stock ARJT bin for a baseline.

I assume I just line up the notch in the chip with the notch in the socket? (Looking at it like in the picture, with the notch on the left)

[EagleMark]

1227747 or any C3 ECM notch goes inside towards Netres chip.

In the Burn 2 chip goes to bottom of soccket away from handle with notch up towards handle.

[corvetteracing]

i had this all workig with the 1995 pcm 16197427 parked car now wont start have code 43 checked wire had burned on header replace knock sensor with white connector for manual , should I have used the black one for auto trannys ???? and wire to pcm B15 place on lap top still showing code 43 & wont start ????? did I short out the pcm ?????? help thoughts would be helpful thanks