Engine Speed Input Circuit No Signal
What does P0727 mean?
The P0727 code means the vehicle's onboard diagnostic system has detected: Engine Speed Input Circuit No Signal. This is a critical severity code.
Common Symptoms
- Check Engine Light illuminated
- Engine cranks but may not start
- No tachometer reading
- Transmission will not shift
Probable Causes (Ranked by Likelihood)
- Failed crankshaft position sensor Very High
- Broken CKP sensor wiring High
- Sheared reluctor ring or key Moderate
- TCM or ECM engine speed circuit failure Low
Step-by-Step Diagnostic Procedure
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Check for engine RPM on scan tool -- 0 RPM while cranking confirms no signal
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Inspect CKP sensor connector for disconnection
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Measure CKP sensor resistance -- compare to spec (typically 200-2000 ohms)
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Check wiring from CKP sensor to ECM and TCM for breaks
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Replace the CKP sensor if it tests faulty
Frequently Asked Questions
Can I drive with code P0727?
Do not drive. Engine Speed Input Circuit No Signal can cause unsafe or unpredictable transmission behavior.
What causes P0727?
The most common cause is a faulty sensor or wiring issue. Failed crankshaft position sensor is the most likely cause.
Is P0727 expensive to fix?
Typical repair costs range from $100 - $350 (parts and labor). Sensor replacement is the most common fix.