Engine Speed Input Circuit Range/Performance (P0726)
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 due to 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 inaccurate reading can cause drivability issues.
01. Most Common Causes
- Faulty crankshaft position sensor
- Damaged or loose wiring/connectors to the sensor
- Incorrect sensor gap or mounting
- Faulty ECM (rare)
02. Symptoms You Will Notice
- Check Engine Light illuminated
- Engine stalling or rough idle
- Hard starting or no start
- Poor acceleration or hesitation
03. Step-by-Step Diagnosis
Step 1: Scan for codes and record freeze frame data.
Step 2: Visually inspect the crankshaft position sensor and wiring for damage or looseness.
Step 3: Test sensor resistance and AC voltage output while cranking (should be ~0.5-1.0V AC).
Step 4: Check sensor gap and alignment; adjust if necessary.
Step 5: If sensor and wiring are good, test ECM input signal; replace ECM if faulty.
04. Commonly Affected Makes
05. Frequently Asked Questions
Is it safe to drive with this code?▼
It is not recommended to drive with P0726 as it can cause stalling or no start, leading to unsafe conditions. Have it diagnosed promptly.
How much does it cost to fix?▼
The cost typically ranges from $50 to $150 for a sensor replacement, plus diagnostic fees. Labor is usually 0.5-1 hour.