If there is incorrect or incomplete contact of the engine control module's ground line, the engine will not function correctly. Therefore, checking before further diagnosis can save a lot of aggravating time.
CAUTION
To prevent the possibility of permanent ECM damage, the ignition switch must
always be OFF when disconnecting power from or reconnecting power to the module.
This includes unplugging the ECM connector, disconnecting the negative battery
cable, removing the unit fuse or even attempting to jump your dead battery using
jumper cables.