What is P0043 fault code? What is the description of HO2S Heater Circuit Low (Bank 1 Sensor 3)? How do I fix the P0043 fault code What are the symptoms and causes for the P0043 fault code
What is the P0043 Fault code? What does it stand for?
The powertrain control module (PCM), when it detects a problem with the heater element in the oxygen (O2) sensor, will set a P0043 code. Vehicles with multiple engine banks will have “Bank 1” and “Sensor 3”. The oxygen sensor closest to the engine is the one that contains cylinder 1.
These sensors measure oxygen levels in the exhaust stream. These sensors can be found in the exhaust manifold, or in the pipe downstream from the manifold. Newer sensors often have a heating element, which allows them to quickly reach operational temperature. To send a voltage signal, they must be at least 572 F. They react faster to mixture changes at higher temperatures (1752 F).
The PCM controls the HO2S heater circuit on some vehicles. Others use a 12V supply battery and a ground wire from the PCM to power the heating element when it is turned on. The PCM monitors the voltage signals within the heater circuits continuously. When voltage signals fall below the specified range, the PCM stores the P0043 fault code.
What is the P0043 Fault Code?
- – Defective oxygen sensor (Bank 1 Sensor 3)
- – HO2S heater circuit, or short to ground (Bank 1 Sensor 3)
- – Blown H2S heater circuit fuse (if necessary)
- – The PCM is not functioning properly or needs to be updated.
What are the symptoms of the P0043 Fault Code?
- – Illumination for the check engine light
- – Sometimes, the engine may not start or it will consume more fuel.
- – Most cases are not accompanied by any symptoms, other than the check engine lamp coming on.
How to Fix the P0043 Fault Code
- – Repair of damaged wires, broken connections and short circuit issues in the HO2S Circuit
- – Replacing fuse for HO2S heater circuit
- – Test the circuit of the sensor and replace the sensor if there is excessive undervoltage (Bank 1 Sensor 3).
- – Reprogramming or replacement for a defective PCM
How Serious Is the P0043 Fault Coding?
P0043 does not typically cause other symptoms than the check-engine light turning on. It is therefore not a serious code. It is recommended that you have the engine checked as soon as possible if it is running irregularly or hard, and if fuel consumption is increasing.
