P0727 critical

Engine Speed Input Circuit No Signal

The P0727 code means the vehicle's onboard diagnostic system has detected: Engine Speed Input Circuit No Signal. This is a critical severity code.

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Keep driving?
No -- stop driving
DIY difficulty
hard
Estimated cost
$100 - $350 (parts and labor)
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ANCEL AD310 OBD-II Scanner

Read and clear transmission codes. Many trans codes are caused by low or burnt fluid -- check level and color before assuming the worst.

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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

  1. Check for engine RPM on scan tool -- 0 RPM while cranking confirms no signal

  2. Inspect CKP sensor connector for disconnection

  3. Measure CKP sensor resistance -- compare to spec (typically 200-2000 ohms)

  4. Check wiring from CKP sensor to ECM and TCM for breaks

  5. 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.

Sources

This page is built from documented references. Verify against your own service info before repair work.

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