OBD-II Trouble Code Description for P0155 GMC

O2 Sensor Heater Circuit

What does this mean?

OBD2 Code P0155 GM definition:
This code definition:the front oxygen sensor on Bank 2. The heated circuit in the oxygen sensor decreases time needed to enter closed loop. As the O2 heater reaches operating temperature, the oxygen sensor responds by switching according to oxygen content of the exhaust surrounding it. The ECM tracks how long it takes for the oxygen sensor to begin switching. It the ECM determines (based on coolant temp) that too much time elapsed before the oxygen sensor began operating properly, it will set P0155 GM. See also: P0135 GM (Bank 1).

Symptoms

Possible sumptoms of OBD code P0155 GM
You will likely notice poor fuel economy the illumination of the MIL.

Causes

Possible causes of OBD code P0155 GM
A code P0155 GM may mean that one or more of the following has happened: O2 Heater element resistance is high Internal short or open in the heater element O2 heater circuit wiring high resistance open or short to ground in the wiring harness

Possible Solutions

Repair short or open or high resistance in wiring harness or harness connectors Replace oxygen sensor (cannot repair open or short that occurs internally to sensor)