What is P2237 fault code exactly? What is the O2 Sensor Positive Current Circuit / Open Bank1 Sensor 1 error code description? How do you fix the P2237 fault code What are the causes and symptoms of the P2238 error code?
What is the P2237 Fault code? What does it all mean?
A P2237 code indicates that the powertrain controller module (PCM), has detected a positive current imbalance in the O2 sensor on engine bank 1. “Bank 1” Is the row of the engine containing the number 1 cylinder. “Sensor 1” This is the oxygen sensor nearest to the engine, prior to the catalytic convert. The negative current control circuit uses a low voltage circuit.
Modern engines use voltage signals from heated oxygen sensor (HO2S), to measure exhaust oxygen and monitor the effectiveness of the catalytic convertor. The oxygen sensor is made from a zirconium dioxide sensing element that is placed in the middle a vented steel enclosure. The oxygen sensor connector connects with small platinum electrodes. All oxygen sensors must be attached to the exhaust pipe. The sensing element is located close to the center line of the pipe. The exhaust gases from combustion chamber are emitted through the exhaust pipes and catalytic converter. They then pass over the oxygen sensors. The exhaust gases fill a small chamber at the center of the sensor, through holes in its housing. The temperature of the chamber heats the air, determining the amount of oxygen ions. This causes changes in the voltage. The PCM interprets the changes in the voltage signal to indicate the oxygen level in the exhaust system. A low signal is indicative of excess oxygen in exhaust (poor conditions), while a high signal indicates that the exhaust has low levels of oxygen (rich conditions). In accordance with this information, the PCM adjusts engine’s air fuel mixture.
If the PCM detects a fault in the heater element control loop of the oxygen sensor and receives no signal or an inconsistent signal, it will set fault code P2237, activate the check engine light, and notify the customer.
Vehicles susceptible to the P2237 fault code include but aren’t limited to: Toyota, Ford and Volkswagen models; Honda, Seat, Acura models; Mazda, BMW, Porsche, Suzuki; Lexus, Peugeot; and Opel models.
What causes the P2237 Fault code?
Fault code P2237 can be triggered by the following common causes:
- Damaged, melted or disconnected wiring and/or connectors for the oxygen sensor internal heat circuit.
- – Poor electrical connections
- – Defective oxygen sensor (Bank 1 Sensor 1)
- – Leakage in the exhaust system
- – A PCM that is not working properly or has to be reprogrammed (rarely).
What are the symptoms of the P2237 Fault code?
You may experience the following symptoms if your vehicle has the code P2237:
- – Turn off the engine light if it is not lit by the PCM.
- – Increased fuel use
- – Engine misfires and irregular running
- – Setting misfire codes, or other fault codes in relation to Rich / Light fuel mixture
- – Exhaust fumes emitting black smoke
- – Reduced engine performance
- Failure to fix the code in a timely manner could lead to the catalytic converter malfunctioning.
- – PCM may enter failsafe mode to limit engine power
How do I fix the P2237 fault code?
There are several repairs that can resolve the P2237 fault code.
- Repair of damaged, melted or broken wiring to the O2 sensor circuit and heater circuit
- – Repairing damaged, corroded and loose, weakly electrified, sockets and connectors
- – Repair of exhaust leaks
- – Replace the O2 sensor if it is damaged.
How Serious Is the P2237 Fault Code
A P2237 code means that there is an open circuit or short circuit in O2 sensor heater circuit. This code may be set on some vehicles so that the PCM can restrict fuel delivery or enter fail-safe mode. There may be misfires and poor engine performance. This code should not be ignored and must be fixed immediately.
