P0372 - Timing Reference High Resolution Signal 'A' Too Few Pulses

P0372 is set when the Engine Control Unit (ECU) detects an insufficient number of pulses from the high-resolution timing reference signal 'A' over a specific period of engine rotation. This high-definition signal (often 360 or 720 pulses per revolution) is used for precise injection and ignition timing control. If the pulse count falls below the calibrated threshold, the ECU loses fine-tuning capability. This can trigger a fail-safe mode, as the engine can no longer guarantee optimal combustion timing, potentially leading to hard starts or stalling.