P03B3

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