O2 Oxygen Sensor Heater Circuit Malfunction (bank 2 sensor 1)
When the P0155 code is present, it is an indication that the heater element of the oxygen sensor is taking longer than the normal to heat up. The power control module (PCM) will store the P0155 trouble code and the Check Engine Light will come on to alert your 2008 Saturn Vue 's operator to the problem.
Some or all of these symptoms may be present with the P0155 trouble code.
In most cases, the presence of this code indicates that the oxygen sensor needs to be replaced. Before doing so, the following steps should be taken:
Use an OBD-II scanner to collect the trouble codes that have been stored by the power control module (PCM).
Visually inspect the wiring that leads to the oxygen sensor for breaks in the wires or bare wires.
Use the OBD-II scanner to view live data in order to make sure the oxygen sensor is working properly.
If the coolant temperature sensor is not operating properly, the power control module (PCM) will store this code as well, so this should be inspected and tested as well.
In rare cases, the power control module (PCM) may be defective and this would require advanced diagnosis to make a determination as to whether this is the problem. This should be considered last, and only after every other possible attempt at repair has failed.
Replacing the oxygen sensor before inspecting the other components
Not inspecting the wires leading to the oxygen sensor for breaks and/or bare wires before the oxygen sensor is replaced
The P0155 trouble code is considered to be a moderately serious code. The reason for this is that drivability problems and poor fuel consumption is possible when this trouble code is present.
The removal of the oxygen sensor can be difficult if you do not have an oxygen sensor set and propane tank . The oxygen sensor can be difficult to reach, depending on your 2008 Saturn Vue . If the oxygen sensor has ceased in the exhaust, which is common, a heating element will be required to remove it.