2018 Gen V swapped in a 55 belair no spark or injector pulse getting a code p0685

[Authority Automotive]

I have a friend that wanted some helping getting is LS swap in his 55 belair running. at first I found there was no spark and no injector pulse so I checked all grounds on the block and body they are good Im getting full voltage at the fuse box while cranking so I completed a VATS delete by going into the VCM editor processor and clicked disable VATS and still no spark or injector pulse. Watched data while cranking and there was RPM signal so I assume the crank sensor is working. The only code I am getting is a p0685. Am I missing something else I am suppose to do to get the vehicle started?

[5FDP]

Was the VATS delete done with a write entire?

Did you disable the starter check if it's there or what about any theft DTC's??


Past that we'd need the tune and logs to see if everything is working and it wants to start.

[Authority Automotive]

I have no theft codes, I did write entire and all I did was disable the vats I did not disable anything else

[5FDP]

If there is a start check in the OS tab, that needs to be disabled.

Would need the tune and a log file to see what else is going on.

[Authority Automotive]

If there is a start check in the OS tab, that needs to be disabled.

Would need the tune and a log file to see what else is going on.

I finally got the vehicle in to my shop and deleted all codes that are no longer related to this vehicle and then did a complete write and everything is working now. Thanks for your help

[jpliss]

Somethign else to look at in the future. If you use the ignition wire from a factory style harness, ensure it is powered during crank. If not you may need to jumper the ignition switch for the power to the ignition wire