P2668 moderate

Cylinder Deactivation System Slow Response

The P2668 code means the vehicle's onboard diagnostic system has detected: Cylinder Deactivation System Slow Response. This is a moderate severity code.

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Keep driving?
Yes, but fix soon
DIY difficulty
hard
Estimated cost
$100 - $1500 (parts and labor)
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Common Symptoms

  • Check Engine Light on
  • Hesitation during V8 to V4 transition
  • Rough mode transitions
  • Slight shudder during deceleration
  • Delayed engagement of cylinder deactivation

Probable Causes (Ranked by Likelihood)

  • Low or contaminated engine oil Very High
  • Worn AFM/DFM oil control valve High
  • Partially clogged oil passages to deactivation lifters Moderate
  • ECM software calibration issue Low

Step-by-Step Diagnostic Procedure

  1. Read freeze frame data and confirm P2668 is present

  2. Check engine oil level and condition

  3. Monitor deactivation solenoid response times with scan tool

  4. Perform oil system service and retest

Frequently Asked Questions

What does P2668 mean?

P2668 indicates a problem with the cylinder deactivation system slow response. This affects the vehicle's ability to deactivate cylinders for improved fuel economy.

Can I drive with a P2668 code?

You can drive with this code, but fuel economy will be reduced since the cylinder deactivation system is disabled.

How much does it cost to fix P2668?

Repairs typically cost $100 - $1500. Simple solenoid replacement is less expensive, but collapsed lifter repair can be $2,000 or more.

Sources

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

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