Every chip I burn results in WinALDL showing an error code of 51 PROM error. OR, With the stock chip, and another one I burned several days ago (an EEPROM) when one of these two chips is loaded, the SES light flickers pretty fast, and with weak lighting (compared to the 'normal' appearance of, say the solid SES light). Are these two chips bad??? One of the chips that acts up like this is a brand new EEPROM,,, This sucks that I can't run the stock chip, or a copy of it..

I know somwone will correct me if I`m wrong,and I may be.I think I read somewhere the fast flickering was the signal for a bad ecm.Was the car running before you started tuning?

I had a similar problem which turned out to be a bad ECM (actually I had 2 bad ones). My SES light would flicker randomly, like a bad connection or something. What ECM are you running? The 86-89 TPI (1227165) ECM's seem prone to cracked solder joints. On one of the bad ECMs I had, I could get the ECM to function normally by presing down on the memcal through the hole in the ECM box, slightly bending the ECM board - that's how I finally figured out it was something wrong with the ECM. I do seem to remember getting a code 51 sometimes too - I'm pretty sure mine had bad solder joints somewhere on the memcal socket.

Sorry, the ecm is a '7747 in a '90 TBI 350 truck... Truck was running before I started messing with it, but always throwing the SES light.

The truck still runs, just always says prom error in winaldl and runs doggy.

A bad ecm? Is there a way to test it??? Where can I get a new one, which ecm(s) will work for me?

This truck is my daily driver.

Thanks!

It's most likely running in limp mode, which will cause poor gas mileage, and reduced power. I would check the junkyard for ECMs, I'd be willing to bet that ECM is in lots of TBI vehicles around '90 model. Check in chevy trucks, vans, f-bodies, caprices, etc - TBI came in a lot of stuff. I don't know of a good way to test an ECM, the factory has specialized equipment for that.

Edit: found an ECM application list:
http://www.cruzers.com/~ludis/c3xref.html#1227747

A rapid flicker I understand is a prom error.

So what do you guys think, is it the ECM or the chip???

I'm half tempted to get another ECM just for a backup anywhich way.

Will I need to look for one with a BCC of ASDU_9567 which is what I had?? Or, will something else work?

Thanks
Chase

I'm going to the junkyard tomorrow, I know they have some other 7747 ECM's, but I don't know if they have one with the chip broadcast code (BCC) ASDU 9567.... Can I use any 'K' engine code 7747 ECM?? Or do I need to get the ASDU that came from my truck. “K”: ACSU, ACSW, AKAL, AKAJ, AKAR, AMUR, ANLW, ANLX, ANLZ, ARHT, ARJT, ARJU, ASDU, ASDW, ASDZ, …



I found this site http://www.cruzers.com/~ludis/c3xref.html#1227747

You can use any '7747. The BCC just refers to what is on the EPROM itself, and has no bearing on using a different BCC in it.

Do you get the rapid flashing SES with the stock EPROM?

Yes.

Thanks!

I have 4 chips total. 3 EEPROMS + 1 stock EPROM. only ONE EEPROM will NOT give a rapid flashing SES, but still says prom error/failure in WinALDL.

Is the chip in ECU correctly? If reversed it may blinky rapid.

Fixed the solder, and determined the stock chip is junk.