* Faulty Ignition Control Module (ICM): This module controls the ignition coils. A bad ICM will prevent spark even if all other components are fine. This is a very common culprit in COP systems.
* Faulty Ignition Coil(s): While you mention replacing the *rotor button* (which doesn't exist on a COP system), did you actually replace the individual ignition coils located directly on top of each spark plug? One or more could be bad even if they visually seem okay. A coil test is needed here.
* Wiring Problems: Look closely at the wiring harness leading to the ignition coils. Inspect for broken wires, corrosion, or poor connections. A damaged wire can disrupt the signal to the coils.
* Camshaft Position Sensor (CMP): While less common than a bad CKP, a faulty CMP sensor can prevent the engine from firing. It's crucial for proper timing.
* Power Issues: Check the fuses and relays related to the ignition system. A blown fuse or bad relay can cut off power. Also, test the battery voltage and ensure it's providing adequate power.
* PCM (Powertrain Control Module) Issues: The PCM controls the entire engine. A faulty PCM could be preventing spark, although this is less likely if the other components are functioning. This is a more advanced diagnostic step.
Troubleshooting Steps:
1. Verify CKP Sensor Installation: Make absolutely certain the crankshaft position sensor is correctly installed. Even a slightly misaligned sensor can prevent proper operation.
2. Test the Ignition Coils: You need a multimeter or a specialized ignition coil tester to check the resistance and function of each ignition coil. A bad coil will show incorrect resistance values.
3. Inspect Wiring: Carefully inspect the wiring harness from the PCM to the coils. Look for visual damage, broken insulation, or corrosion.
4. Check for Codes: Use an OBD-II scanner to read any diagnostic trouble codes (DTCs) stored in the PCM. These codes can pinpoint the problem.
5. Test CMP Sensor: If the above steps don't yield results, testing the camshaft position sensor would be next. This often requires a scan tool or multimeter.
Recommendation: If you're not comfortable performing these tests, it's best to take your Cirrus to a qualified mechanic. Diagnosing ignition problems can be tricky and requires specialized equipment. Continuing to troubleshoot without proper tools and knowledge could lead to further damage.
