OBD Guide

P28B1

Cylinder 9 Ion Current Sense Circuit Range/Performance

P28B1 is an OBD-II diagnostic trouble code meaning: Cylinder 9 Ion Current Sense Circuit Range/Performance. Common causes: open or short circuit in the ion current circuit, malfunction of the spark plug of the 9th cylinder. Estimated repair cost: $17–67.

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

Symptoms

  • Unstable engine operation
  • Power Loss
  • Increased fuel consumption
  • Check Engine Light Illuminates
  • Possible misfire in cylinder 9

Causes

  • Open or short circuit in the ion current circuit
  • Malfunction of the spark plug of the 9th cylinder
  • Problems with the ignition coil
  • Low cylinder compression
  • Engine control unit malfunction

How to Fix

  1. Check the integrity of the ion current circuit of the 9th cylinder
  2. Replace the spark plug in cylinder 9
  3. Check and, if necessary, replace the ignition coil
  4. Measure compression in cylinder 9
  5. Diagnose the engine control unit

Related codes

Error P28B1 by Vehicle Brand

FAQ

What does the P28B1 code mean?

P28B1 is an OBD-II diagnostic trouble code that indicates: Cylinder 9 Ion Current Sense Circuit Range/Performance

What causes a P28B1 error code?

The most common causes of P28B1 include: Open or short circuit in the ion current circuit; Malfunction of the spark plug of the 9th cylinder; Problems with the ignition coil; Low cylinder compression.

How do I fix a P28B1 diagnostic trouble code?

To fix P28B1: Check the integrity of the ion current circuit of the 9th cylinder. Replace the spark plug in cylinder 9. Check and, if necessary, replace the ignition coil. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P28B1?

Limited driving only, diagnose soon

How much does it cost to fix P28B1?

The estimated repair cost for P28B1 is $17–67. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat