OBD Guide

P03B3

Cylinder 4 Pressure Sensor Circuit

P03B3 is an OBD-II diagnostic trouble code meaning: Cylinder 4 Pressure Sensor Circuit. Common causes: open or short circuit in the cylinder 4 pressure sensor circuit, faulty pressure sensor. Estimated repair cost: $33–133.

Severity
⚠️ Medium
Can you drive?
Do not drive — repair immediately
Approx. repair cost
$33–133 (est.)

Symptoms

  • Check Engine light on
  • Reduced efficiency of cylinder 4
  • Slight reduction in engine power
  • Slight deterioration in fuel consumption
  • Possible misfire

Causes

  • Open or short circuit in the cylinder 4 pressure sensor circuit
  • Faulty pressure sensor
  • Damaged or oxidized sensor connector
  • Damage to the sensor wiring harness
  • ECU malfunction (extremely rare)

How to Fix

  1. Check pressure sensor circuit fuses
  2. Inspect the connector and wiring of the cylinder 4 pressure sensor
  3. Check the presence of power (usually 5V) at the sensor
  4. Check the sensor ground circuit
  5. Measure the sensor resistance and compare with the norm
  6. Replace the sensor if it is confirmed to be faulty

Related codes

Error P03B3 by Vehicle Brand

FAQ

What does the P03B3 code mean?

P03B3 is an OBD-II diagnostic trouble code that indicates: Cylinder 4 Pressure Sensor Circuit

What causes a P03B3 error code?

The most common causes of P03B3 include: Open or short circuit in the cylinder 4 pressure sensor circuit; Faulty pressure sensor; Damaged or oxidized sensor connector; Damage to the sensor wiring harness.

How do I fix a P03B3 diagnostic trouble code?

To fix P03B3: Check pressure sensor circuit fuses. Inspect the connector and wiring of the cylinder 4 pressure sensor. Check the presence of power (usually 5V) at the sensor. For a complete diagnosis, use an OBD-II scanner.

Is it safe to drive with P03B3?

Do not drive — repair immediately

How much does it cost to fix P03B3?

The estimated repair cost for P03B3 is $33–133. Actual cost depends on your vehicle, location, and labor rates.

See also: Russian version · NationStat