OBD Guide

P12F8

Cylinder Deactivation Exhaust Flow Valve Feedback Circuit Low Frequency Bank 2

P12F8 is an OBD-II diagnostic trouble code meaning: Cylinder Deactivation Exhaust Flow Valve Feedback Circuit Low Frequency Bank 2. Common causes: malfunction of the exhaust gas flow control valve, open or short in the feedback circuit. Estimated repair cost: $33–89.

Severity
⚠️ Medium
Can you drive?
Yes, but get it checked soon
Approx. repair cost
$33–89 (est.)

Symptoms

  • Deterioration in acceleration dynamics
  • Increased fuel consumption
  • Unstable engine operation
  • Check engine light comes on
  • Disabling the cylinder deactivation system

Causes

  • Malfunction of the exhaust gas flow control valve
  • Open or short in the feedback circuit
  • Poor contact in valve connector
  • Problems with the engine control unit
  • Contact corrosion

How to Fix

  1. Check the integrity of the valve feedback circuit
  2. Check valve resistance and operation
  3. Inspect connectors and contacts for corrosion
  4. If necessary, replace the exhaust gas flow control valve
  5. Reset the code and check the system operation

Related codes

FAQ

What does the P12F8 code mean?

P12F8 is an OBD-II diagnostic trouble code that indicates: Cylinder Deactivation Exhaust Flow Valve Feedback Circuit Low Frequency Bank 2

What causes a P12F8 error code?

The most common causes of P12F8 include: Malfunction of the exhaust gas flow control valve; Open or short in the feedback circuit; Poor contact in valve connector; Problems with the engine control unit.

How do I fix a P12F8 diagnostic trouble code?

To fix P12F8: Check the integrity of the valve feedback circuit. Check valve resistance and operation. Inspect connectors and contacts for corrosion. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P12F8?

Yes, but get it checked soon

How much does it cost to fix P12F8?

The estimated repair cost for P12F8 is $33–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat