P0728 moderate

Engine Speed Input Circuit Intermittent

The P0728 code means the vehicle's onboard diagnostic system has detected: Engine Speed Input Circuit Intermittent. This is a moderate severity code.

My Garage →
Keep driving?
Short distances only
DIY difficulty
hard
Estimated cost
$100 - $350 (parts and labor)
Check Your Fluid First
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.

Check Price on Amazon

Affiliate link -- we earn a commission at no extra cost to you.

Read Transmission Codes
LAUNCH CRP123X (Reads All Systems)

Basic scanners only read engine codes. This reads transmission, ABS, and airbag too.

Check Price on Amazon

Affiliate link -- we earn a commission at no extra cost to you.

Common Symptoms

  • Check Engine Light illuminated intermittently
  • Random engine stalling
  • Occasional harsh shifting
  • Sporadic tachometer fluctuations

Probable Causes (Ranked by Likelihood)

  • Loose CKP sensor connector Very High
  • Intermittent break in CKP sensor wiring High
  • CKP sensor air gap changing with vibration Moderate
  • Failing CKP sensor Moderate

Step-by-Step Diagnostic Procedure

  1. Wiggle CKP sensor connector while monitoring RPM on a scan tool

  2. Check CKP sensor mounting bolt for tightness

  3. Inspect wiring for damage at stress points

  4. Monitor RPM signal during driving for dropouts

  5. Replace CKP sensor if intermittent signal continues

Frequently Asked Questions

Can I drive with code P0728?

Drive short distances only. Engine Speed Input Circuit Intermittent can cause unsafe or unpredictable transmission behavior.

What causes P0728?

The most common cause is a faulty sensor or wiring issue. Loose CKP sensor connector is the most likely cause.

Is P0728 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.

Explore More

Was this helpful?

Share carcodefinder.com with a friend who needs to decode their check engine light.