What does O2 sensor circuit high mean?
What does O2 sensor circuit high mean?
The high voltage condition from the O2 sensor is indicating a lack of oxygen in the exhaust or other related problems, such as a leaking fuel injector or a broken up catalyst inside.
Why is my O2 sensor still reading the same code?
If you have to drive 10 minutes before the Check Engine light comes on with the same code with the new O2 sensors, then the O2 sensor may be getting coated or contaminated where it can no longer read the oxygen content in the exhaust gasses and the voltage signal from the O2 sensor remains high.
How do you test an O2 sensor in the garage?
Connect the red lead of the voltmeter to the O2 sensor’s signal wire using a back probe test lead. Take the black lead and connect it to a good ground. After connecting the leads, start the engine until it’s warmed up and reaches close-loop operation.
What is the diagnostic code for O2 sensor circuit Bank 2?
P0138 is a diagnostic trouble code (DTC) for “O2 Sensor Circuit High Voltage (Bank 1, Sensor 2)”.
When to shut off O2 sensor heater circuit?
Some computer systems will shut the O 2 heater circuit off until the codes are cleared. Now, with the ignition switch off, plug the test harness with the light into the vehicle’s O 2 sensor harness connection. The light should remain off until the engine is started. Once the engine is running, the light should come on steady or blink.
When does the O2 sensor turn on the Check Engine light?
The engine control module (ECM) sees the voltage of the O2 sensor for bank 1 sensor 2 above 1.2 volts when the ECM has commanded the fuel to a targeted lean condition on that bank of the engine. The ECM detects the voltage high problem and turns on the Check Engine Light.
What should I do if my O2 sensor is high?
Monitors O2 sensor data to see if the voltage is switching back and forth between low and high at a fast rate compared to other sensors. Checks the O2 sensor wiring and the harness connections for any corrosion in the connections. Checks the O2 sensor for any physical damage or fluid contamination. Checks for exhaust leaks before the sensor.
How to diagnose O2 sensor 1 for bank 1?
O2 sensor 1 for bank 1 can be used to diagnose O2 sensor 2 for bank 1 by looking at both sensors operation for comparison. The operation should be nearly the same, except sensor 2 should have a lower O2 reading since the catalyst should burn off the excess fuel and oxygen.
What is the diagnostic code for O2 sensor circuit high voltage?
P0138 is a diagnostic trouble code (DTC) for “O2 Sensor Circuit High Voltage (Bank 1, Sensor 2)”. This can happen for multiple reasons and a mechanic needs to diagnose the specific cause for this code to be triggered in your situation.
