P0161 2/2 O2 Sensor Heater Failure
NAME OF CODEO2 Sensor Heater Failure
WHEN MONITORED
The O2 Heater Monitor runs during O2 sensor cool-down period, after a hot drive cycle, when engine is shut-down with the ignition key turned "OFF".
SET CONDITION
Using O2 sensor signal voltage readings, during O2 sensor cool-down period, with heater OFF compared to O2 sensor signal voltage with heater ON.
THEORY OF OPERATION
The oxygen sensor is a voltage generating device. The PCM receives exhaust gas information from this O2 sensor. The sensor detects exhaust gas content by a galvanic reaction within the sensor that produces a voltage. After measuring the amount of oxygen in the exhaust gases. This O2 sensor serves as an indicator of oxygen content. The heater element helps the O2 sensor quickly reach a normal and steady operating temperature, which is required for proper emission control.
POSSIBLE CAUSES
- Open heater element circuit
- O2 sensor failure
- O2 heater wiring
- Powertrain control module failure
- Connector terminals
- Connector wires
- ASD Fuse(s)
- Open ASD Relay Circuit