Set a code 51 eprom error and now its gone

[INEEDAGN]

I had the instrument cluster loose today at work to lube the speedometer cable, halfway through it I had to pick up my daughter from preschool. I ran it with the instrument cluster loose which kept the alternator from charging, i shut it off at home and had to jump it to get back to work. At work I figured out the whole alternator charge light thing, the battery is old and didnt pass a load test after charging so I replaced it. After battery replacement the car will randomly die. Set a code 42 est circuit failure once and then it did a code 51 eprom error thereafter. Which puts it in calpak mode which doesnt agree with my 60 lb injectors and translator plus/extender setup too well LOL. Unhooked the ecm and reset it and it sat in the driveway and ran fine for a long time. I didn't know if it was just a random glitch with battery replacement or if low voltage driving around town might have damaged the ecm or eprom. I have a spare ecm with turbotweak chip I can throw in it if it does it again, and I'll know this weekend when I take it 2 1/2 hours from home . Has anyone ran into a similar problem? I can't drive it anymore over the next couple days, gonna road test it on the way to KC.

 

[INEEDAGN]

I should add that the car died multiple times on me, the extender chip anti theft sequence has a courtesy mode which means that if the engine stalls, you don't have to redo the anti theft sequence as long as the key is not turned to the off position. Well that feature wasnt working. It wouldn't restart until I shut the key off and reset the anti theft sequence. Making me wonder about the eprom. It did this 3-4 times until I reset the ecm and now it hasn't acted up since then.

 

[TurboBob]

loose or corroded chip socket? try retensioning the fingers in the socket.

Bob

 

[mgmshar]

I'm one of those people who programs his own PROM chips. I occasionally will program a chip on my programmer, confirm that it's OK in the programmer, and have it do the kinds of things you describe when I put it in the ECU. Sometimes I can see that one of the pins is bent or otherwise out of place. Other times I just program another chip with the exact same program, install it, and it works fine.

As Bob said, take the PROM chip out and take a close look at the pins. If any are out of place or bend, try gently bending them back. If that doesn't work, try your other chip.

Good luck,

Mike
Sent from my HTC Droid Incredible using Turbo Buick

 

[TurboBob]

Over the years I have seen a couple chips get flaky, but have seen more than a few sockets get loose. They were not designed to be unplugged and re-plugged as many times as we do it.

So use a small safety pin or something similar and bend the fingers out a little.

I can reburn the chip for you as well.

Bob

 

[INEEDAGN]

I figured if the chip really did flake out, that you'd reburn it for me. The thing about the pins is, I can't think of a single time I've had the chip out of that ecm since I stuck it in there 4-5 years ago. Since I have multiple 148 ecms laying here, I can use a different ecm for every chip, which I have no need to change because the translator plus is just that freaking awesome. I had a local guy burn me a low timing street chip for stock injectors years ago at a gathering and it ran fine except under boost. It was like the valet mode in the extender chip. He reburned it and all was well and I still have it. I will casually mention that the ECM is a GM reman unit.

It hasn't missed a beat since I reset the ECM. If it gives me any trouble I'll mess with the chip socket, etc. Spare ecm is in the trunk along with the TT chip I bought used "just incase". The only time I ever used the TT chip was when someone wanted to buy a stock ecm and maf from me, so I converted it back to stock to test them both. The "normal" ecm wasn't touched. Anyway, guess that 'bout sums up this thread. Thanks for the input!


Oh, did I mention how stupid GM is? The wires for the boost gauge and tach are routed back behind the dash harness through a clip so there's no f'n way to completely remove the damn cluster without ripping the dash apart. I managed to lube the cable with the cluster still in my way. If the cluster would ever have to come out of the car, I'm cutting the wires to the tach/boost gauge. They are both worthless anyway and I have a spare that I'll hand to the next owner. (rant over)

 

[RmvBfrFlght]

With the issues starting after the battery replacement I would double and triple check that the battery cables are tight.

RemoveBeforeFlight

 

[TurboBob]

With the issues starting after the battery replacement I would double and triple check that the battery cables are tight.

RemoveBeforeFlight

the memory backup wire also.

 

[TurboBob]

....


Oh, did I mention how stupid GM is? The wires for the boost gauge and tach are routed back behind the dash harness through a clip so there's no f'n way to completely remove the damn cluster without ripping the dash apart. I managed to lube the cable with the cluster still in my way. If the cluster would ever have to come out of the car, I'm cutting the wires to the tach/boost gauge. They are both worthless anyway and I have a spare that I'll hand to the next owner. (rant over)

I just pulled mine out last week. You can get it, but your arms will be a bit scraped up. If you can keep from cutting the wires, the core is worth more.

I recalibrated mine myself (pain in the A), Caspers service on these is really the way to go. I wanted mine working because the new ignition system has features that use the tach and I don't want to install an aftermarket one.

Bob

 

[INEEDAGN]

I got the car out today. Made it 3 miles down the highway, died. code 51. Took the chip out of the socket, stared at it for a minute, didn't see anything out of place, put it back in. Drove it around another 20 miles and it hasn't missed a beat. If it does it again I'm putting the extender chip in a known good ecm and driving it again, if it happens after that I'll swap to the TT chip and suspect the extender chip. But it might have just needed a wiggle. I will look at the battery cables again and the ecm wire just for grins.

 

[INEEDAGN]

Put a good 6 hours driving time on it this weekend. Never missed a beat, except once it died backing into a parking stall in Topeka. A/C was on and it didn't get much idle time since the battery reset, so I figured that was probably an IAC reset issue. If you don't hear from me again, assume it's not broken