OBD Guide

P3421

Cylinder 3 Exhaust Valve Control Circuit/Open

P3421 is an OBD-II diagnostic trouble code meaning: Cylinder 3 Exhaust Valve Control Circuit/Open. Common causes: broken wiring to the valve of the 3rd cylinder, solenoid valve malfunction. Estimated repair cost: $17–89.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$17–89 (est.)

Symptoms

  • Unstable engine operation
  • Power Loss
  • Increased fuel consumption
  • Check Engine Light Is On
  • Possible misfire in cylinder 3

Causes

  • Broken wiring to the valve of the 3rd cylinder
  • Solenoid valve malfunction
  • Problems with the engine control unit
  • Short circuit in the circuit
  • Mechanical failure of the valve mechanism

How to Fix

  1. Check the integrity of the wiring to the valve
  2. Test solenoid valve resistance
  3. Check connector contacts
  4. Diagnose the engine control unit
  5. If necessary, replace the faulty valve

Related codes

Error P3421 by Vehicle Brand

FAQ

What does the P3421 code mean?

P3421 is an OBD-II diagnostic trouble code that indicates: Cylinder 3 Exhaust Valve Control Circuit/Open

What causes a P3421 error code?

The most common causes of P3421 include: Broken wiring to the valve of the 3rd cylinder; Solenoid valve malfunction; Problems with the engine control unit; Short circuit in the circuit.

How do I fix a P3421 diagnostic trouble code?

To fix P3421: Check the integrity of the wiring to the valve. Test solenoid valve resistance. Check connector contacts. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P3421?

Limited driving only, diagnose soon

How much does it cost to fix P3421?

The estimated repair cost for P3421 is $17–89. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat