Check all ground connections to the controller to ensure they are connected exactly as described in the manual and that they are not damaged.
It is very important not to use the body for ground as this can cause strange, intermittent behavior in the controller that is hard to diagnose.
Pins 15 and 16 are combined and must be connected directly to the engine ECU's main ground wire, as close to the ECU as possible.
ground connection in EFI