I posted this in the conversions & hybrids section, but have not gotten much response.

I am almost finished with the LS1/T56 swap into my 96 Impala SS.

status web page

I used the 2001 LS1 harness and the 96 LT1 harness. I used the LT1 underhood fuses/relays/harness and mapped all of the wires from the LS1 harness. It cranks and my fuel pump comes on, but I get no spark and I am unable to connect with AutoTap to see what is going on. AutoTap is working fine (connected to another vehicle). I confirmed the wiring, BAT and GND at the DLC as well as checked the BAT, IGN and serial data connections at the PCM. I get nothing from AutoTap.

How can I confirm that my PCM is good (anyone near Austin, TX have one I can try or a car I can plug mine into)? Can a dealer test it on the bench?

I did plug my laptop into a 2002 Tahoo and it works fine, so it is not my laptop or cable.

Thanks for any help or suggestions.

Scott

 

may like to chk the fuse for cig lighter as this fuse supple power to OBD connection

 

I know it is not the fuse as I have pulled the PCM and powered it on the bench as follows:

C1/C2 pins 1 and 40 > ground

C1 pin 19 > fused 12 volts with switch to simulate ignition switch

C1 pin 20 > fused 12 volts

C1 pin 57 > fused 12 volts

C1 pin 58 > serial data

I connected pins 4 and 5 on the DLC connector to ground, pin 2 to serial data and pin 16 to fused 12 volts.

Even with this very simplified “harness” I can not connect to the PCM.

The pin 16 provided power for the GM Tech 2. I am not sure if AutoTap or LS1Edit actually needs this power as the laptop has its own power, but I provided fused 12 volts on this pin anyway.

Thanks,
Scott

 

Problem solved. The person I purchased the engine and trans from neglected to mention that the PCM was new and had never been flashed.

Thanks,
Scott