P0155 - 02 HEATER CIRCUIT MALFUNCTION SENSOR (BANK 2, SENSOR 1)

The Oxygen Sensor (O2) is equipped with a heating element, which reduces the time for the sensor to enter a closed loop. This diagnostic code refers to the front Oxygen Sensor (O2) in the bank number 2. When the O2 sensor heating element reaches operating temperature, the O2 sensor responds by switching according to the surrounding exhaust oxygen content.

The Engine Control Module (ECM) monitors the time taken by the O2 sensor to switch. Setting the fault code P0155 OBD2 means that the Oxygen Sensor (O2) heating element is exceeding the time limit set for it to heat up.

• The Check Engine light comes on.
• Fuel consumption is more than usual.
• The vehicle may constantly be shut down.
• Black smoke comes out of the exhaust.

The code P0155 OBD II could be established because of the following facts:

• The heating element resistance of the Oxygen Sensor (O2) may be high.
• The heating element of the Oxygen Sensor (O2) may be short-circuited.
• Perhaps a fuse in the O2 sensor circuit has been damaged.
•  The Coolant Temperature Sensor is not working properly.
• The O2 sensor (Bank 2, Sensor 1) may be defective.

To solve the diagnostic code P0155, you could do the following:

• Perform an inspection of the cable system leading to the Oxygen Sensor (O2). Make sure they are in good condition, not worn or rubbing against other components. If you find inconsistencies in any of these, repair or replace it if necessary.
• Changes the O2 sensor (Bank 2, Sensor 1).