HO2S Heater Resistance (Bank 2, Sensor 1)
How does a P0059 code trigger the check engine light? This code will trigger the check engine light as follows:
The vehicle Powertrain Control Module monitors the oxygen sensor heater control circuit current draw. The check engine light will illuminate when the current requirements are too high or too low.
Possible causes for this check engine light code include:
Blown oxygen sensor fuse
Open circuit in oxygen sensor harness
Open circuit internal to oxygen sensor
Open circuit in PCM
Short circuit in oxygen sensor harness
Short circuit internal to oxygen sensor
Short circuit internal to PCM
To diagnose a P0059 check engine light code we will need to test out the oxygen sensor wiring and also test the circuits through the oxygen sensor itself. The internal processor circuits are a possible cause but are much less likely, so the other areas are thoroughly tested first. See our article Automotive Circuit Testing 101, if you need more assistance with this. If concern is determined to be intermittent, check out our article on Intermittent Diagnosis and wiggle test connectors and wiring, attempting to duplicate concern. You may also use the “Get Help” link if you need specifications or have any other related questions. Remember to refer to an appropriate manual for specific instruction.