OBD Guide

P21D8

Cylinder 10 Injector B Circuit/Open

P21D8 is an OBD-II diagnostic trouble code meaning: Cylinder 10 Injector B Circuit/Open. Common causes: open or short circuit in the injector circuit, cylinder 10 injector malfunction. Estimated repair cost: $17–56.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$17–56 (est.)

Symptoms

  • Misfire in cylinder 10
  • Reduced engine power
  • Increased fuel consumption
  • Unstable engine idling
  • Check Engine Light Illuminates

Causes

  • Open or short circuit in the injector circuit
  • Cylinder 10 injector malfunction
  • Problems with the engine control unit
  • Wiring harness damage
  • Corroded contacts or poor connection

How to Fix

  1. Check the integrity of the injector circuit
  2. Measure the injector resistance
  3. Check connections and contacts
  4. Replace the faulty injector if necessary
  5. Check and replace damaged wires

Related codes

Error P21D8 by Vehicle Brand

FAQ

What does the P21D8 code mean?

P21D8 is an OBD-II diagnostic trouble code that indicates: Cylinder 10 Injector B Circuit/Open

What causes a P21D8 error code?

The most common causes of P21D8 include: Open or short circuit in the injector circuit; Cylinder 10 injector malfunction; Problems with the engine control unit; Wiring harness damage.

How do I fix a P21D8 diagnostic trouble code?

To fix P21D8: Check the integrity of the injector circuit. Measure the injector resistance. Check connections and contacts. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P21D8?

Limited driving only, diagnose soon

How much does it cost to fix P21D8?

The estimated repair cost for P21D8 is $17–56. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat