Is there a relay for ecm? Where is it?
I recently had to charge my battery while in the car, and the battery leaked acid into fog lite relay shorting;
1] fog lite bulb
2) BURNing wire to bulb in fog lite contol switch in half
3) ruined fog lite relay.

I have since fixed these issues, but now I am receiving error code: 5-1 [ecm prom checksum bad]. In addition I am now having trouble getting computer into diagnostic mode jumping a&b on connector under dash. I now have to flash ign key on/off and/or disconnect reconnect battery, several attempts each time to finally get computer diagnostics mode active. If I am lucky enough it will work for a while then just quit, error codes are:

1) 1-2 [NO RPM]
2) 5-1 [BAD ECM PROM CHECKSUM]

Where is the Electronic Control Module on 88GTA w/350, TPI ? Wells book tells me to inspect said module?

Engine will sometimes start & run for a little while 20-50 minutes then just quit. I have to unhook battery & let sit for a while to get restarted.

Someone help Meeeee~

 

The ECM is most likely a silver box up underneath the passenger side of the dash. Check above the kick panel

 

I have an 89 gta and I am on my third ecu in ten years. It doesnt take much to toast one. On the plus side they are relatively cheap to replace. My last one cost around 85 bucks at autozone with a one year warranty. Next time you put a charger on your battery I would suggest disconnecting the negative cable. And when you swap the ecu disconnect both cables and turn the ignition to the run position for a few seconds to drain any residual power that may be in the system. Some of the circuitry inside the ecu runs on 5 volts instead of 12 so the slightest arc will fry it.

 

Thanks for info on that, it most likely is Prom/memcal going bad. The ecu has been acting strange for some time, finally zap, dead. Also my Prom that plugs into ecu has gone bad, that rectangular Blue/tan box. I replaced ecu seveal times and nothing, still no responses. Where can I find one of those at reasonable cost? The ecu is a 1227165 with broadcast code of AKXZ marked on factory case & on chip.

Thankx,

 

A new prom is probably going to run you anywhere from $150 to $250 or more depending on which one you go with. IIRC the dealer charged me right around $180 about five years ago and aftermarket ones are generally more. I don't know if they can be tested or not. To troubleshoot mine I found a car for sale on a local lot with the same engine and took it for a test drive to "borrow" the prom for a minute. Kinda risky but I felt a lot better paying that much when I knew for sure it was bad rather than buying an expensive, non returnable part and hoping. If you look around you can probably find a good used one. Check the classifieds here, I just scored one for $50 bucks. As long as its from a 165 ecm and the donor car has the same engine and trans it should work.