What is the P0151 fault number? What is the description of O2 Sensor Circuit Low Voltage Bank 2 Sensor1 malfunction? How can you fix P0151 fault code What are the symptoms and causes for the P0151 fault code
What is the P0151 fault code? What does it all mean?
A code P0151 stands for “O2 Sensor Circuit Low Voltage (Bank 2, Sensor 1).” This means that the oxygen sensor voltage remains lower than factory specifications (below 0.21 volts) for a period of time (more than 2 minutes).
The P0151 fault code is very similar to P0136 and P0137. This code means that the “upstream oxygen sensor” is malfunctioning and the catalytic convertor on Bank 2 is not working properly. This sensor determines how much oxygen is in the exhaust before it enters a catalytic convertor. This information is used by the powertrain control module (PCM), to adjust vehicle’s air/fuel ratio. “Bank 2” refers to the bank in which the engine’s number 2 is located.
The PCM constantly tests the catalytic converter using voltage signals from downstream O2 sensors. If the PCM finds that the upstream O2 sensor signal is lower than specified, it will turn on the engine check lamp and assign fault code P0151. Low voltage signals indicate excess oxygen in exhaust. At the command of PCM, injectors will inject additional fuel to make the engine run richer.
What is the P0151 Fault Code and Why Does It Happen?
P0151 fault codes can activate for a variety of reasons. Here are the most common causes.
- – Defective O2 sensor (Bank 2 Sensor 1)
- – An issue with the circuit of O2 sensor (e.g., damaged wires, corrosion, or loose connections).
- – Poor working conditions
- Exhaust leaks could be present near or in front the O2 sensor. When the engine is cold, exhaust leaks can be more severe but may decrease when the engine heats up.
What are the symptoms for P0151’s Fault Code?
- – Illumination for check engine light
- – The engine in the rich mixture will consume excessive fuel
- – Engine hard start
- – Inadequate engine performance during acceleration
How to Fix the P0151 Fault Code
- – Replace the O2 sensor if tests reveal a failed sensor
- – Replace or repair wiring or connections to O2 sensor
- – Repair of exhaust leaks
- – Remediating oil and coolant leaks which could cause contamination to the sensors
How serious is the P0151 Fault code?
The O2 sensor may be defective, and the PCM will not be able to control the engine’s fuel/air mixture ratio. This results in extremely high fuel consumption that can contaminate spark plugs.
