Engine Speed Input Circuit Range/Performance
The P0726 code indicates that the Engine Control Module (ECM) has detected an engine speed (RPM) signal from the crankshaft position sensor that is outside the expected range or not performing correctly. This can be caused by a faulty sensor, wiring issues, or mechanical problems affecting the signal. The ECM uses this signal for fuel injection, ignition timing, and other critical functions, so an incorrect reading can lead to drivability issues.
1. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine may crank but not start
- Engine stalling or rough idle
- Poor acceleration or hesitation
- Intermittent no-start conditions
2. Most Common Causes
- Faulty crankshaft position sensor
- Damaged or corroded wiring/connectors to the sensor
- Incorrect sensor gap or mounting
- Damaged reluctor ring (tone wheel) on the crankshaft
- ECM software or hardware failure (rare)
3. Step-by-Step Diagnosis
Step 1: Use an OBD2 scanner to confirm the code and check for additional codes.
Step 2: Visually inspect the crankshaft position sensor and its wiring for damage, corrosion, or loose connections.
Step 3: Test the sensor's resistance and output voltage with a multimeter according to manufacturer specifications.
Step 4: Check the reluctor ring for damage or debris that could affect the signal.
Step 5: If all else is normal, replace the crankshaft position sensor and clear the code.
4. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with P0726 as it can cause stalling, poor performance, or a no-start condition, which could be dangerous.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for a DIY sensor replacement, or $150 to $300 if done by a shop including labor.
5. Commonly Affected Makes
This is a generic OBD2 code, potentially applicable to any manufacturer using this diagnostic standard.