What is the P0143 fault code What is the O2 Sensor Circuit Low Voltage Bank 1, Sensor 3 malfunction description? How to fix P0143 fault code What are the causes and symptoms of the P0143 error code?
What is the P0143 fault code? What does it all mean?
When the powertrain control module, PCM detects that the oxygen sensor signal voltage is lower than the factory specifications, a code P0143 will be set. The description of the code states that the bank containing engine’s number 1 cylinder is “Bank 1”. “Sensor 3”, refers to O2 sensor located furthest away from the engine, following the catalytic converter.
It is crucial to ensure that the catalytic conversion works efficiently. Failing to operate the catalytic converter can result in reduced engine performance and increased harmful emissions. The PCM uses both upstream oxygen sensors, which are located before the catalytic engine, to calculate the amount of fuel to inject into an engine. It also uses downstream sensors to monitor the efficiency and performance of the catalytic generator. These sensors are located on both the exhaust manifolds and exhaust pipes.
The voltage signals of the sensor vary depending on how much oxygen is in the exhaust. The exhaust is considered to be lean if it contains too much oxygen. A voltage of 0.9V means that the exhaust has been enriched. The PCM will trigger a P0143 code if it detects that the voltage signal from O2 sensor is too low for a given time (e.g., less than 156mV)
The P0143 fault code can affect Chevrolet (especially Silverado), Ford and GMC as well as Jeep, GMC, Jeep and Volkswagen.
What is the P0143 Fault Code and Why Does It Happen?
This error code could be triggered by:
- – Defective oxygen sensor (bank 1 sensor 3)
- – Wiring issues with the O2 sensor circuit (short and open wires touching the exhaust)
- False readings due to air leakage in the exhaust
- – Defective PCM
What are the symptoms for P0143 fault code?
The following symptoms may be experienced by anyone who has a vehicle coded P0143.
- – Illumination for the check engine light
- – Increased exhaust emissions
- If the exhaust is leaking, exhaust gases could seep into the passenger compartment.
The post-catalyst O2 sensors don’t cause any issues with driveability as they do nothing to affect fuel delivery, but instead monitor the effectiveness of the catalyst. If other codes are used in conjunction with P0143, engine performance problems such as poor idle, rich, or lean conditions, can arise.
How to Fix the P0143 Fault Code
- – Check for any exhaust damage or leaks that could cause the O2 sensor to malfunction before installing it. Repair if necessary.
- Repair or replace the wiring or connections to O2 sensor, bank 1 sensor 3.
- – Replacing O2 sensor (bank 1, sensor 3)
