Slow388LT4

iTrader: (2)

Anyone out there do the EFI 24X swap on there 1994 Fbody? Cant get the ECM to read or program with the supplied OBDII connection . . The ECM is not bad, for it can be programmed direct on the bench??
Thanks

mmihm06

iTrader: (2)

Make sure your harness is pinned properly at the ECM, i can't remember what pin the serial data wire is supposed to be right now. And check your pinouts at the 3 engine-to-car connectors as well, the connectors are the same but they switched around the pins over the years...just went through this swapping my 94 harness into a 96. Pinouts can be found at shbox.com

Also, make sure you have 12 volts at pin 16 on the ALDL connector under the dash, and grounds on pins 4 and 5. Pin 2 should be serial data, and you should have continuity between that and your ECM connector.

95mysticta

iTrader: (4)

X2 you have check the pinouts of the aldl connector. I had to do the same for my 94. Its been two yrs cant remember what had to be done. SHBOX outlines what your 94 is wired out as and you need to match it to a 96+