3.1 ECM Issue

[jmgtp]

1990 Beretta GT
5 speed
~100k miles

Car ran perfectly... parked it for 3 days, today it did a start/stall several times. Then it started and loped terribly, opening up the throttle resulted in severe bog and basically no increase in engine RPM.

Now the extra weird shit:
1.) It was about 80* outside... but as soon as I turned the key on (before I even cranked) the engine temp gauge was about 1/3 of the way up (it's usually at bottom of the scale at this outside temp)
2.) Battery Voltage gauge registered absolutely nothing (this car has the digital dash so all info that the dash gets is fed via the ecm *I believe*)
3.) Radiator fan runs any time the ignition is on
4.) This is the kicker, no SES light when key on with engine off AND no SES light when I jumped the aldl terminals to pull codes

At first I thought the coolant temp sender was bad or disconnected because the ecm fan was on at all times but then the display of 0 volts (which is obviously wrong since the battery had plenty of juice to crank the engine) and the lack of an SES light made me think otherwise.

So... safe to assume the ECM is the problem... but is the ecm toasted or just the eeprom? Because it did start and idle, (with a +/-400 rpm lope!) maybe this is limp home mode?

Question 2: if the ecm was good but the eeprom was bad would the dash display the SES before startup and when I jump the aldl terminals?

I'm basically trying to find out if the eeprom is to blame or if the whole ecm clunked out.

I didn't investigate more than jumping the terminals because I had to go somewhere so I took another car... and it's a bit dark out now to tinker with it. I'll pop the cover off the ecm tommorow and make sure the memcal is seated, but I imagine they don't come loose so easily.

Anyone got an ecm for sale?
Beats me what the ## is, but I'm sure someone can fill me in on that. All I can say for it is that its by the glovebox, it's metal cased and doesn't have weather-pack connectors. Ben burned the chip I have been using for the past 6 months or so; as far as I know it's a stock code chip that I had him enable lean cruise on.

Thanks
-John

O ya... I'm officially 22 yrs old today... so a free ecm would make a sweet birthday gift

[DEI37]

Sounds like it did indeed fry an ECM. I almost want to say the the chip may still be good, but the computer itself is toast. I THINK that's the way it works. The fan being on is an indicator that it is roasted.

[jmgtp]

Ya, I talked to Ben afterwards and he came to about the same conclusion. I purchased an ecm from an 88 (so I gotta throw in my chip) on ebay but it hasn't arrived yet. Today I turned the key on and was playing with the radio for a few minutes all the while the fan running and gauges whacked out. BUT, then after 5 mins or so, the fan stopped gauges returned to normal and the SES light came on! I turned the key and it started and ran normal. Shut it off, key back on and the fan was on and no SES again! I hope that was just a fluke and that the ECM is really bad... otherwise I may have a faulty wiring problem

[TheDirtyBen]

when you jump the aldl, do you get code 12? one pulse, then two? if not, then ECM is definitely toast.

btw, why did ya go the ebay route? i can get em all day long at the junkyard for $40.

[jmgtp]

Ya, as stated above, even when I jump them I don't get diagnostic code 12.

O you can get them for $40? Boy do I feed like a chump! I only paid $27 shipped to my door for one. Can I paypal you the $13 just for piece of mind? :P

[TheDirtyBen]

sure, send it here. cuz if mine don't work, i can take it back the same day and exchange it for another one. no shipping involved and no waiting.