OBD Guide

P21D1

Cylinder 3 Injector B Circuit/Open

P21D1 is an OBD-II diagnostic trouble code meaning: Cylinder 3 Injector B Circuit/Open. Common causes: open or short circuit in the injector circuit, cylinder 3 injector malfunction. Estimated repair cost: $17–67.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$17–67 (est.)

Symptoms

  • Uneven engine operation
  • Increased fuel consumption
  • Reduced engine power
  • Check Engine Light Is On
  • Possible misfire in cylinder 3

Causes

  • Open or short circuit in the injector circuit
  • Cylinder 3 injector malfunction
  • Problems with the injector connector
  • Engine control unit malfunction
  • Wiring harness damage

How to Fix

  1. Check the resistance of the injector of cylinder 3
  2. Inspect wiring and connectors for damage
  3. Check for voltage at the injector
  4. Replace the faulty injector if necessary
  5. Reset the error code and check if it returns

Related codes

Error P21D1 by Vehicle Brand

FAQ

What does the P21D1 code mean?

P21D1 is an OBD-II diagnostic trouble code that indicates: Cylinder 3 Injector B Circuit/Open

What causes a P21D1 error code?

The most common causes of P21D1 include: Open or short circuit in the injector circuit; Cylinder 3 injector malfunction; Problems with the injector connector; Engine control unit malfunction.

How do I fix a P21D1 diagnostic trouble code?

To fix P21D1: Check the resistance of the injector of cylinder 3. Inspect wiring and connectors for damage. Check for voltage at the injector. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P21D1?

Limited driving only, diagnose soon

How much does it cost to fix P21D1?

The estimated repair cost for P21D1 is $17–67. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat