OBD Guide

P21F2

Cylinder 12 Injector B Circuit Low

P21F2 is an OBD-II diagnostic trouble code meaning: Cylinder 12 Injector B Circuit Low. Common causes: malfunction of the fuel injector of cylinder 12, open or short circuit in control circuit. Estimated repair cost: $28–89.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$28–89 (est.)

Symptoms

  • Unstable engine operation
  • Power reduction
  • Increased fuel consumption
  • Misfire in cylinder 12
  • Check Engine Light Is On

Causes

  • Malfunction of the fuel injector of cylinder 12
  • Open or short circuit in control circuit
  • Poor contact in the injector connectors
  • Engine control unit malfunction
  • Problems with injector power supply

How to Fix

  1. Check the resistance of the injector of cylinder 12
  2. Inspect the wiring harness and connectors for damage.
  3. Check the voltage in the injector control circuit
  4. If necessary, replace the faulty injector
  5. Scan the control unit for other errors

Related codes

Error P21F2 by Vehicle Brand

FAQ

What does the P21F2 code mean?

P21F2 is an OBD-II diagnostic trouble code that indicates: Cylinder 12 Injector B Circuit Low

What causes a P21F2 error code?

The most common causes of P21F2 include: Malfunction of the fuel injector of cylinder 12; Open or short circuit in control circuit; Poor contact in the injector connectors; Engine control unit malfunction.

How do I fix a P21F2 diagnostic trouble code?

To fix P21F2: Check the resistance of the injector of cylinder 12. Inspect the wiring harness and connectors for damage.. Check the voltage in the injector control circuit. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P21F2?

Limited driving only, diagnose soon

How much does it cost to fix P21F2?

The estimated repair cost for P21F2 is $28–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat