What the P0139 code means. P0139 is the OBD-II generic code indicating that the O2 sensor for bank 1 sensor 2 failed to have a voltage drop below . 2 volts for 7 seconds during a deceleration fuel cut off. This failure shows that the engine control module (ECM) has determined the sensor response is too slow.
What causes code P0139?
Diagnostic trouble code (DTC) P0139 stands for “O2 Sensor Circuit Slow Response (Bank 1, sensor 2).” It indicates that the powertrain control module (PCM) has detected a potential issue with the signal from the rear oxygen sensor on bank 1.
How do you fix a low voltage O2 sensor?
Repair any exhaust leaks before the sensor to prevent excess oxygen getting into the exhaust stream causing the low voltage readings. Check the O2 sensor for oil or coolant contaminants that could foul the sensor. Repair any harness that is damaged properly to prevent erratic readings from the sensors.
How do you fix a delayed O2 sensor?
How To Correct P013E O2 Sensor Delayed Response – Rich to Lean (Bank 1 Sensor 2)
- Replacing of faulty Heated Oxygen Sensor.
- Repairing the broken, damaged and burnt circuit wiring of the sensor.
- Effectively checking the troubleshooting ECM/PCM and replacing the components if needed.
What causes low voltage in downstream O2 sensor?
Too low fuel pressure can cause the engine to run lean, causing the O2 sensor to read low voltage as described in step 3. In this case, the sensor is accurate, and the lean running condition needs to be fixed.
How do I fix code P0139?
What repairs can fix the P0139 code?
- The O2 sensor for bank 1 sensor 2 should be replaced only after all other checks of the fuel and exhaust systems test okay.
- Testing the fuel system and replacing a leaking injector.
- Replacing the catalyst in front of the sensor.
What causes oxygen sensor slow response?
If the oxygen sensor is contaminated, the most common codes are P0139 to P0153 for oxygen sensor circuit slow response. These codes are set when the engine management system sees a lower than expected signal voltage, or the sensor is not switching from rich to lean.
What causes low voltage to a sensor?
A low voltage signal from the oxygen sensor indicates low oxygen content in the exhaust—a sign that the engine runs rich. The PCM responds by reducing the fuel going to the engine.
How do you check an O2 sensor?
How to test an Oxygen Sensor with a Clamp-meter
- Make sure the engine exhaust system is cold.
- Switch the clamp-meter on, to ‘DC current/DC amperage’ mode.
- Put the clamp around either of the oxygen sensor heater power wires (but not both). …
- Turn the engine on.
- Observe the reading, which should be between 0.25A and 1.5A.
Where is oxygen sensor located?
Location of the Oxygen sensor
These sensors are always located in the exhaust gas flow of your vehicle. Most cars have one O2 sensor located close to the engine, typically in the exhaust manifold. Some cars have two O2 sensors or more, and the second Oxygen sensor is typically installed behind the catalytic converter.
What does O2 sensor delayed response mean?
It means that your vehicle’s powertrain control module (PCM) has detected a delayed response time from the upstream oxygen sensor on Bank 1. Usually, any issue with the upstream oxygen sensor’s function can cause a decrease in engine performance, but it typically just triggers a Check Engine light.
How do you clean O2 sensors?
Zitat von Youtube: Take it out you know spray. It let it soak. Again you know rinse and repeat a couple of times try to get as much of the gunk out as possible. However you're very unlikely to be able to get.