Oxygen Sensor Heater Circuit Malfunction (Bank 2 Sensor 1)

FAULT ID
P0155

TITLE
Oxygen Sensor Circuit Malfunction (Bank 2 Sensor 1)

BACKGROUND
The engine control module checks whether the heater current is within a specified range when the heater is energized.

RANGE OF CHECK & SET CONDITIONS
The oxygen sensor heater current is either lower than several dozen milliamperes or higher than several amperes.

EFFECT
Limp-in

PROBABLE CAUSES
- Open or shorted oxygen sensor heater circuit.
- Open circuit in oxygen sensor heater.
- Engine control module failed.