OBD Guide

P03B2

Cylinder 3 Combustion Performance

P03B2 is an OBD-II diagnostic trouble code meaning: Cylinder 3 Combustion Performance. Common causes: worn spark plug in cylinder 3, malfunction of ignition coil/high voltage wire. Estimated repair cost: $22–167.

Severity
⚠️ Medium
Can you drive?
Limited driving only, diagnose soon
Approx. repair cost
$22–167 (est.)

Symptoms

  • Unstable engine operation
  • Vibration at idle and under load
  • Power Loss
  • Increased fuel consumption
  • Possible misfire in cylinder 3

Causes

  • Worn spark plug in cylinder 3
  • Malfunction of ignition coil/high voltage wire
  • Nozzle contamination/coking
  • Low cylinder compression
  • Uneven wear of piston rings
  • Valve sealing problems
  • Malfunction of the camshaft position sensor (for systems with VVT)

How to Fix

  1. Read all fault codes and stored freeze frame data
  2. Conduct a visual inspection of the ignition system elements in cylinder 3
  3. Measure the compression in the problem cylinder
  4. Check the condition of the spark plug
  5. Evaluate the operation of the fuel injector (balance test or ultrasonic cleaning)
  6. Test ignition coil/high voltage wire
  7. If necessary, replace faulty components
  8. Reset ECM adaptations after repair

Related codes

Error P03B2 by Vehicle Brand

FAQ

What does the P03B2 code mean?

P03B2 is an OBD-II diagnostic trouble code that indicates: Cylinder 3 Combustion Performance

What causes a P03B2 error code?

The most common causes of P03B2 include: Worn spark plug in cylinder 3; Malfunction of ignition coil/high voltage wire; Nozzle contamination/coking; Low cylinder compression.

How do I fix a P03B2 diagnostic trouble code?

To fix P03B2: Read all fault codes and stored freeze frame data. Conduct a visual inspection of the ignition system elements in cylinder 3. Measure the compression in the problem cylinder. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P03B2?

Limited driving only, diagnose soon

How much does it cost to fix P03B2?

The estimated repair cost for P03B2 is $22–167. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat