2011 Chevrolet Spark 1.2L Model with P0351 and P0352 Fault: No Spark, Fuel Pump Works, ECU Replacement Attempted

My 2011 Chevrolet Spark 1.2L has stopped starting completely after spending two months at a Chevrolet dealership. The technician initially diagnosed the issue as a faulty ECU and fuel pump, quoting an extremely high repair cost—up to 1000% more than typical in Indonesia. I took the ECU to Darwin, Australia for inspection, where it was confirmed as functional. After replacing the ECU back in Borneo, the car still failed to start. I then purchased an OBD2 scanner and found fault codes P0351 and P0352. The ECU was sent to Surabaya, Indonesia for repair; they reported that the ECU had been fixed but required a coil replacement. However, after installing the new coil, there is still no spark. I have replaced the spark plugs and ignition leads, yet no spark is detected during cranking. The fuel pump operates normally—audible sound when activated—and the crankshaft position sensor (CPS) is working as confirmed by OBD readings showing RPM feedback while cranking. I am currently measuring 12.4 volts at the center pin of the coil, which suggests proper power supply. Despite this, no spark occurs. I have no idea what to do next. The issue appears to be related to ignition system triggering or ECU signal delivery. Could it be a wiring issue, faulty coil, or an ECU that is not properly communicating with the coils? Any guidance on diagnosing whether the ECU is sending signals to the coils would be greatly appreciated.