I have a 1988 GMC Sierra 1500 truck with a stock 1227747 ECM that now won’t start.


Here’s the problem, I was trying to solve a progressively worse idle/ stall situation:



  • Tried to install “tuner pro” software from a purchased disc, anti-virus would not allow the full install
  • New ALDL cable plugged in from truck to laptop
  • Started the truck, ran for 15 seconds, then died.
  • Downloaded “winALDL” from the internet, “freescan 207”
  • Now I can see 4 rows only of data while cranking......no start!
  • Tried the paperclip trick.....no codes
  • Tried resetting the ECM by disconnecting the battery.
  • Confirmed no spark via timing light, now fuel via visual



After a couple of days off from the above, now it fires for 3 seconds and dies.


Hopefully someone here can help get my truck back up and running. Did I fry my ECM?? What should I be looking at to troubleshoot?


Thanks in advance!
88 GMC