P0373
UniversalTiming Reference High Resolution Signal A Intermittent/Erratic Pulses
Medium SeverityThis code indicates that the Powertrain Control Module (PCM) is receiving inconsistent or erratic signals from the crankshaft position sensor or camshaft position sensor, which are crucial for engine timing. This can lead to significant engine performance problems, including stalling or a no-start condition.
⚠️ Before You Begin (Safety First)
Always ensure the vehicle is turned off and cool before beginning any inspection or repair. Disconnect the battery's negative terminal before working on electrical components to prevent accidental shorts or injury. Use appropriate personal protective equipment, such as gloves and eye protection.
Common Symptoms
- Check Engine Light illuminated
- Engine misfires or rough idle
- Engine stalls unexpectedly
- Difficulty starting the engine
- Reduced engine performance
- Hesitation or poor acceleration
Common Causes
- Faulty crankshaft position sensor
- Faulty camshaft position sensor
- Damaged or corroded wiring/connector for the sensor
- Interference from other electrical components
- Loose or damaged reluctor wheel/tone ring
- PCM malfunction (rare)
Frequently reported on: General/Universal
Diagnostic Steps
- Retrieve and record all stored DTCs using an OBD-II scanner.
- Visually inspect the crankshaft and camshaft position sensors and their wiring harnesses for any visible damage, frayed wires, or loose connections.
- Check the sensor connectors for corrosion or bent pins. Clean or repair as necessary.
- If accessible, gently wiggle the wiring while the engine is running (if it starts) to see if the symptoms change, indicating an intermittent connection.
- With the ignition off and battery disconnected, test the resistance of the sensor (if specifications are available) and check for voltage at the connector.
- If the sensor wiring and connections appear sound, consider replacing the suspected faulty crankshaft or camshaft position sensor.
- Clear the code and test drive the vehicle to see if the code returns.
👨🔧 When to Call a Professional
If the code reappears immediately after clearing or if you experience significant engine misfires, stalling, or a no-start condition, it is best to consult a professional mechanic for advanced diagnostics.
Commonly Asked Questions
Can I drive with a P0373 code?
It is not recommended to drive with this code for an extended period. An intermittent timing signal can cause your engine to stall unexpectedly, potentially leading to dangerous situations or further engine damage.
Is the crankshaft position sensor or camshaft position sensor more likely to be the problem?
Both are equally possible culprits for P0373. Often, the crankshaft position sensor is more critical for engine operation and can cause more severe symptoms if faulty. Diagnosis should focus on both.
How can I tell if the sensor is truly bad or if it's just a wiring issue?
A thorough visual inspection of the wiring for cuts, chafing, or corrosion is the first step. You can also use a multimeter to check for proper voltage supply and signal output from the sensor, and for continuity in the wiring.
What is a reluctor wheel and how does it relate to this code?
The reluctor wheel (also known as a tone ring or trigger wheel) is a notched wheel that rotates with the crankshaft or camshaft. The sensor detects these notches to determine the engine's position and speed. Damage or misalignment to this wheel can cause erratic signals, triggering P0373.
After replacing the sensor, do I need to clear the code?
Yes, after replacing any component, it's essential to clear the Diagnostic Trouble Code (DTC) using an OBD-II scanner. Then, test drive the vehicle to ensure the repair was successful and the code does not return.