I have just finished installing a street and Performance TPI kit into my land cruiser. My symtoms are that when I turn the key on I get a quick blink of the check engine light but then it gos out. the truck will only start heavily advanced and it apears that the is no ECM control over the timing. If I jump A and B still no light. Tried to read with scan tool but failed to regonize ECM If I remove prom light comes on and stays on. Seems odd that resister packs don't take over for a bad eprom Any thoughts would be greatly appreiciated GM 1227730 Thanks Dave

I had a similar problem with my car, although I got no SES light at all, ever. Make sure the ECM constant power is hooked up and getting power, that turned out to be most of my problem. Are you not able to pull codes at all by jumping pins A+B? My ECM turned out to have a bad PROM socket, but the SES light would flicker on and off randomly (after I fixed the ECM constant power issue).

Thanks for the reply
I have pulled the ecm and checked the varios pins for both 12 volts and grounds. The motor will run if the timing is advanced
enough. It seems that the calpacs are suspect?
I will do another round of metering today.
Thanks Dave

I read your thread about the problem with the ses light...

And my car is doing the same thing,but the ses light will work and sometimes it doesnt...

It depends on the inside temp of the car.If the car has been sitting outside in the sun the ecm will get hot and the light will not function properly.but if I let the ecm cool off then the ses light will work correctly...

I checked all the 12V and ground pins to the ecm and there checking good"when the problem is happening"...

I read that you were suspecting a bad eprom..

well my question is did u fix the proublem?? and ifso how did you?? Thanks.............

Just curious how old is the actual ECM you are using? Has it at least been rebuilt? Your symptoms sound alot like the ECM itself is failing. Where did you get the ECM from?

I the past 3 months I replaced the ecm 3 times with a rebuilt unit from autozone...and ses light will function properly for a couple of days to a week...then it will only blink 1 time then off,and wont come back on...and when it's not working it wont let me pull any codes not even code 12...

The same prom chip has been used on all of the ecm's that I have replaced...since the rebuilt ecm's from auto zone require you to use your original prom.