Timing Reference High Resolution Signal A Too Few Pulses
Your engine's crankshaft position sensor isn't sending enough timing pulses to the ECU, like a metronome skipping beats. The computer can't properly sync ignition and fuel injection without these signals.
The ECU monitors the high-resolution crankshaft position sensor (CKP) signal for a specific number of pulses per crankshaft revolution. When pulse count falls below the expected threshold, the ECU detects a signal deficiency and triggers P0373. This sensor provides critical timing data for ignition and fuel injection synchronization.
| Parameter | Normal Range | Fault Condition |
|---|---|---|
| CKP Signal Pulses Per Revolution | 58-60 pulses (or model-specific count) | Below minimum threshold; insufficient pulse count detected |
| Signal Frequency/Consistency | Continuous, regular pulse pattern | Intermittent or degraded signal quality |
Code P0373 is a moderate fault. You can generally drive to a workshop, but avoid long trips or high-load driving (motorway, uphill towing) until it is diagnosed. If the code keeps returning after clearing, or if you notice the symptoms listed above worsening, do not delay professional diagnosis. Many moderate codes have multiple possible root causes — a mechanic with live OBD data can identify the exact fault more efficiently than part-by-part trial and error.
Once the fault is repaired, P0373 can be cleared using any OBD-II scanner. Connect the scanner, navigate to "Clear Codes" or "Erase DTCs," and confirm. The check engine light turns off immediately.
The code will return if the root cause was not actually fixed. The ECM re-detects the fault within 1–3 drive cycles and sets the code again.