2007 Ford Mustang 4.0L P0300 Random Misfire Detected - No Spark, Won't Start
I recently replaced the serpentine belt, ensuring it was routed correctly. After installation, the yellow engine warning light illuminated. I drove to Oreilly's for a diagnostic scan, which returned code P0300 — Random Misfire Detected. The engine ran smoothly at the time and has not shown any misfiring symptoms during regular use over the past week. However, one week later while driving on the highway, the car suddenly shut off and would not restart. Fuel pump activates and both fuse and relay are confirmed good. There is no ignition spark reaching the plugs. I replaced the ignition module, but the issue persists — engine turns over without spark and will not start. What could be causing this? Any insights or troubleshooting steps would be greatly appreciated.
Please confirm if you have any current diagnostic codes. Is there absolutely no spark at all on the plugs? Next, check for 12 volts at the coil pack. Then verify the switching signal — use a test light to see if it flashes properly. Could the crankshaft position sensor (CKP) have been disturbed during belt installation? Consider inspecting the CKP electrical connector, which is located between the bottom pulley and the belt tensioner.