I am looking to by a spare PCM to keep in my trunk along with the spare ICM (newer Delco) that I have now. I have found several locally and will probably go with the 88999198 PCM but am wondering about the EPROM in them. Anybody know the compatible EPROM'* that will work in a 1988 C engine. I have heard that GM updated the EPROM often and was wondering if a newer issued EPROM would give better service. Any input on the above would be greatly appreciated.
I would also like to know what spare parts you guys keep in your trunk just in case you go dead way out somewhere. Can any relays make you stranded?
I currently carry a spare ICM and soon to be a spare PCM also.

Thanks

My somewhat educated guess is that you'll need a chip from a '88-'90 h-bod. I think that they changed a few things in '91, and that might have included the chip.

Right now my trunk stash includes jumper cables (not sure how old the battery is, and it'* iffy on those really cold days), and my old coil/icm unit (haven't had the new one on for long enough to be comfortable with it yet).

Lets see... I carry every tool I own [about 40% of trunk space], jumper cables [the good thick 30lb kind], battery charger [needs 110v, but i use it all the time], two ICM'* [old magnavox and spare delco, coils only for the magnavox], fluids [oil, tranny, coolant], wd-40/pb blaster, fsm, haynes, vacuum lines [about 20ft], big box of misc screws bolts nuts etc, rear passenger'* door panel, glove box, kitty litter, and most importantly of all --a cell phone.

I think I am prepared to take on the challenge of fixing just about anything that can be fixed on the side of the road. That, and there really isn't much space for all this stuff anywhere else. I usually have a sandwhich too, but that never lasts long in my hands.

You can grab an ECU from ANY 88-91 H-Body. Be sure to test your spare before throwing it in the trunk . Also, throw some bubble wrap around it, and try to keep it well stored, you don't want to kill a perfectly good ECU because you didn't package it nicely. H-Bodies include, Bonnevilles [duh], Park Avenue, LeSebre, Eight Eight, and something else I think I am forgetting. But, you get the point.


-justin

Good point about the jumper cables. Nothing less than 6 gauge wire, preferably 2 or 4. I've walked up to two cars having a hard time jump starting one of them with smaller cables, loaned them my 4 gauge, and the dead car was running right away. Size does matter.

Mine'* 0 gauge. JMFC is right, size does matter... at least in this case .


-justin

The two PCMs (actually were ECMs for the "C" 3800, with no "E" transmission and no ABS were 1228253 and 16198264. These are functionally identical - may just have been relabeled when the numbers changed - and either may be used.

PROM aka MemCal aka CalPac is unique to the specific year/axle ratio/engine/model but must be a "5B" (3800 engine family). These are identified by a four numeric digit code in the PROM memory and a four letter code in the parts book and on the PROM label.

Oh yeah... forgot about differences in final drive, etc. Best to get the number off of yours and hunt down the exact thing, I suppose.

Then again, what usually fails? The chip or the ECM? Because if it'* just the ECM and the PROM chip is still good, you could just get an empty ECM, and swap your chip into it as necessary, right?

Gee, I must have a LOT more faith in the electrical components in my car than some of you folk. About the worst thing that ever happened to me was the original alternator failed about 85,000 miles ago and I got home on battery power. Last summer the cam magnet disintegrated and I drove with the CEL on for about 2 weeks before I replaced it. So the only thing I carry in the trunk besides a spare tire is a spare(old) serpentine belt, some assorted sockets including an 18mm socket and breaker bar just in case I have to either put a new belt on, or possiblly replace the alternator. That and I'm a paid up menber with the Mobil Auto Club!

If I had the space to put all my crap elsewhere, I probably wouldn't carry much anything with me. But, since that isn't the case, it'* all in the trunk.


-justin