To operate efficiently, an engine must have the correct air-fuel ratio. The PCM/ECM (powertrain control module) decides how much fuel is injected into the engine. The sensors around the engine help it calculate the correct levels. The oxygen sensor (O2) is one of its most important components. Oxygen sensors can be found before and after the catalyst converter. When calculating fuel distribution, the PCM uses signal 1 from sensor 1. The PCM uses the sensor 2 signal to determine the condition of a catalytic convert.
To function correctly and to transmit accurate data, each oxygen sensor needs to warm up. The sensor has a heating cable that allows it to reach its operating temperature faster. The PCM will set the P0037 error code if it receives either a low voltage from the heating circuit of the sensor 2 after the catalytic convert or if it does not receive any signal. The row 1 is the side of your engine that contains the number one cylinder.
This particular fault code is common to Toyota, VW (especially Nissan Titan), Ford, Honda and Chevrolet.
Table of Contents
What Are the Causes of Fault Code P0037?
- Faulty oxygen sensors (Bank 1, Sensor 2)
- Faulty sensor heater circuit
- If fitted, O2 sensor fuse has blown
- Damaged cables and poor connections can cause problems with the heater control circuit.
What are the symptoms of fault code P0037?
The vehicle will still run if the fault is in the oxygen sensor heating control circuit. You may still experience symptoms such as
- The engine fault light is illuminated
- Increased exhaust emissions
- The PCM can put the engine in safe mode
- Engine performance problems
- Fuel consumption increases
How to Fix Fault Code P0037?
- If the code appears again, check the O2 sensors cables and connections.
- Cables are damaged by excessive heat from the exhaust.
- Any cable problems, such as fraying or breaking the cables, should be repaired.
- Check the connector connections, and tighten if necessary.
- It is possible that the fuse for O2 sensor heating circuit has blown. Replace it if needed.
- Test the O2 sensor with a voltmeter. If the O2 sensor is defective, replace it.
How serious is fault code P0037?
The PCM will put the engine in safe mode when it detects an error with the O2 sensor heating circuit. Depending on the vehicle’s manufacturer, safe mode can lead to a variety of driving problems. Safe mode will remain active until the problem is corrected. Engine hesitation, irregular operation and reduced performance are possible symptoms. It is important to diagnose the fault as quickly as possible in order to avoid damage to other components.
