P0374
UniversalThe Powertrain Control Module (PCM) has not detected the expected high-resolution timing reference pulses from sensor "A".
High SeverityThis code indicates that the Powertrain Control Module (PCM) is not receiving the necessary high-resolution timing pulses from the crankshaft position sensor or a related timing reference sensor. This lack of signal prevents the PCM from accurately determining engine speed and position, which can lead to a no-start condition or severe engine performance issues.
⚠️ Before You Begin (Safety First)
Always ensure your vehicle is parked on a level surface with the parking brake engaged before attempting any work. Allow the engine to cool down to prevent burns. Disconnect the battery's negative terminal before working on electrical components to avoid accidental shorts or shocks.
Common Symptoms
- Engine cranks but does not start
- Engine stalls unexpectedly
- Rough idling or misfires
- Reduced engine power
- Check Engine Light illuminated
Common Causes
- Faulty Crankshaft Position Sensor (CKP) or Camshaft Position Sensor (CMP)
- Damaged or corroded wiring or connectors to the sensor
- Shorted or open circuit in the sensor harness
- Missing or damaged reluctor wheel (tone ring) on the crankshaft or camshaft
- Faulty Powertrain Control Module (PCM) (rare)
Frequently reported on: General/Universal
Diagnostic Steps
- Visually inspect the Crankshaft Position Sensor and its wiring harness for any obvious damage, frayed wires, or loose connections.
- Check for signs of corrosion at the sensor connector and clean if necessary.
- Using a digital multimeter, check for proper voltage supply to the sensor and verify the sensor's resistance (refer to a vehicle-specific repair manual for values).
- If accessible, remove the sensor and inspect for physical damage or metal shavings sticking to its magnetic tip.
- Ensure the engine's main timing components are intact and the reluctor wheel is not damaged (this often requires more extensive inspection).
👨🔧 When to Call a Professional
If after basic checks of wiring and connectors you cannot pinpoint the issue or if you suspect an internal engine timing problem, it is crucial to consult a professional mechanic for advanced diagnostics, especially using an oscilloscope to verify sensor signal integrity.
Commonly Asked Questions
Can I drive with a P0374 code?
No, it is highly unadvised to drive with this code as it indicates a critical engine timing signal loss, which can lead to engine stalling or prevent it from starting.
What's the difference between a crankshaft and camshaft position sensor?
The crankshaft sensor typically tells the PCM the exact position of the crankshaft for fuel injection and ignition timing, while the camshaft sensor tells the PCM the position of the camshafts to determine which cylinder is on its compression stroke. Code P0374 usually points to the primary timing reference, often the crankshaft.
Is it possible to clear the code after fixing the sensor?
Yes, after repairing or replacing the faulty component, you can clear the code using an OBD-II scanner. It is recommended to perform a test drive to ensure the repair was successful and the code does not return.
What if the sensor is replaced but the code returns?
If the code returns after replacing the sensor, the issue might be with the wiring harness, the reluctor wheel (tone ring) itself, or, less commonly, the Powertrain Control Module (PCM). Further electrical diagnostics are required.
How can I test the crankshaft position sensor?
You can test the sensor by checking for proper voltage supply, ground, and signal output using a multimeter or oscilloscope, following the specific procedure outlined in your vehicle's service manual.