Ecm/prom error?

[TheApocalyptican]

Got my tuning stuff today. Did all the socket work and everything, burnt up a chip, and took it out to the truck and got a flickering SES light, and wasn't able to connect in tunerpro.
Took the ECM back out, reburned the chip, then reflowed the solder on the board, put everything back together, took it out to the truck and it worked.
Drove the truck to datalog, came home, modded my VE table, burnt it to the chip and now I've got the stupid flickering SES again.
Took the computer out again checked the boards contacts for continuity to other parts of the board, made sure they weren't showing continuity to each other, also checked from the pins on the board to the actual part where the chips legs contact the socket.
Everything checked out as good. None of the traces on the boards look bad. Also, the chips erase, read, and re write fine according to flash and burn/tunerpro.

Ideas?

[EagleMark]

Chip has a notch, some go in and if you put it in wrong will damage chip. Some notch goes out like in a Memcal and IIRC will not damage chip if put in backwards.

What ECM, what chip? Offsets set correctly?

[TheApocalyptican]

7747 ECM.
Notch has been installed towards handle in the programmer and in the zif every time.
Offsets set per moates site: 00F000 -> 00FFFF for chip and 000000 -> 000FFF for buffer, with 27SF512 chips at 4k size.
Did originally do one chip at wrong offset, but erased it and also switched to my other chip which has been done correctly from the start and DID work when I went to datalog.

[TheApocalyptican]

Just tried reburning a chip again. Installed it and had flickering light, then light turned solid and everything works correctly again. Confused now!

[FSJ Guy]

Really odd....

You may also want to disconnect your ECM for a few seconds to clear the prom error code. I don't think that will solve your issue, but it's worth a try.

If you install the chip backwards in the '7747 ECM you will know it because your chip will get hot and no longer work after that. AMHIK.

The Burn2 program usually automatically sets the correct offset unless you go and manually change things. Double check that your have the chip securely seated in the ZIF, especially if your ECM is mounted with the chip facing the ground.

[EagleMark]

Just tried reburning a chip again. Installed it and had flickering light, then light turned solid and everything works correctly again. Confused now!

That's not right. With the chip in tap the ECM and see if it starts to flicker or stops. It sounds like a bad solder connection.

CEL should come on blink once and stay solid till engine is started.

When I was asking about the notch I was talking about in the ECM. 1227747 should be inside pointing to netres chip.

[JeepsAndGuns]

I know back in my 7747 days, if I ever turned on the key without a chip in the ecm, and got the flickering light, I would have to unhook the battery to clear the ecm before it would work again. Even if I put a proper chip back in, I would still get the flickering light untill I reset it.

[TheApocalyptican]

Since I got it working last night it has stayed working. A bad solder joint it what I figured the first time. I am far from being new to soldering but I figured, mistakes happen, so I went back and reflowed 'em all. Still had the problem after that. Checked all the traces where I worked with a multimeter and everything was fine. This is a big part of why I am confused at the problem.

I tried the whole unplug the ecm to reset it trick, and it wasn't helping.

I've got it working now tho, so I'll let you guys know if there's another problem or if I figure out what's funny.

[TheApocalyptican]

Still working just fine!

Had another question and didn't wanna keep flooding the forum with new posts:

My ecm is seeing batt voltage 1v below what the actual batt and alt voltage is. As a result, it has gotten down to the high 11v's at idle with accessories on. Isn't this too low for the ecm?
Should I run a new fused wire from the batt to the ecm and thus bypassing the fuse block?

[JeepsAndGuns]

Sounds like you need a bigger alternator, and battery. 11 volts at idle, wow
But if it is still showing a 1 volt diffrence, then I would think there something wrong with the wiring, and yea, I would probably run a new wire. But if its still getting down to 12v with engine running, I would definatly look into a better alt.

[TheApocalyptican]

Well the ecm is getting to the high 11's. Lowest ever was 11.7. But, I checked the batt volts vs the ECM and the ecm is a full volt lower, so I was somewhere around 12.7v at the batt at idle. This was with my stereo on, amps on and my a/c with aux fans on. I've currently got a 140amp CS-144 alt. Should have gone with the AD-244like in my Blazer tho.