Timing Reference High Resolution Signal A Intermittent/Erratic Pulses
The P0373 code indicates that the Powertrain Control Module (PCM) has detected intermittent or erratic pulses from the high-resolution timing reference signal A. This signal is typically generated by the crankshaft position sensor or camshaft position sensor and is used for precise ignition timing and fuel injection control. Erratic pulses can cause misfires, poor performance, and may prevent the engine from starting. Common causes include a faulty sensor, damaged wiring, or issues with the reluctor wheel.
01. Most Common Causes
- Faulty crankshaft or camshaft position sensor
- Damaged or corroded wiring/connectors to the sensor
- Damaged reluctor wheel (missing teeth or debris)
- Intermittent electrical connection or short circuit
- PCM software or hardware failure (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine misfire or rough idle
- Hard starting or no start condition
- Reduced engine power and poor fuel economy
03. Step-by-Step Diagnosis
Step 1: Scan for additional codes and freeze frame data to identify related issues.
Step 2: Visually inspect the crankshaft/camshaft position sensor wiring and connector for damage, corrosion, or loose connections.
Step 3: Test the sensor's resistance and AC voltage output using a multimeter while cranking the engine.
Step 4: Inspect the reluctor wheel for damage, missing teeth, or debris through the sensor mounting hole.
Step 5: If all checks pass, replace the sensor and clear codes; if problem persists, test PCM signal circuit.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with P0373 as it can cause engine stalling, misfires, and potential damage to the catalytic converter. Have the vehicle diagnosed and repaired promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for a sensor replacement, including parts and labor. Additional costs may apply if wiring repairs or PCM replacement is needed.