Error Code P0137
Moderate Issue
DTC Code P0137 indicates a low voltage issue in the O2 Sensor Circuit for Bank 1 Sensor 2. This code is triggered when the Engine Control Module (ECM) detects that the Heated Oxygen Sensor (HO2S) voltage is less than 50 mV, suggesting a potential short to ground.
What symptoms indicate Error Code P0137?
- Engine Light ON: The check engine light or service engine soon warning light illuminates, indicating an issue with the O2 sensor circuit. This is often linked to
such as a faulty O2 sensor or wiring issues. - High Fuel Consumption: The vehicle may experience increased fuel consumption due to incorrect air-fuel mixture readings. This symptom is often associated with
like a malfunctioning O2 sensor or exhaust leaks. - Excessive Smoke from Exhaust: There may be visible excessive smoke from the exhaust, which can be a result of improper combustion. This symptom is typically linked to
such as a defective O2 sensor or issues in the exhaust system.
What causes OBD code Error Code P0137?
- The rear heated oxygen sensor on Bank 1 may be faulty, leading to incorrect voltage readings.
- An open or shorted harness in the rear heated oxygen sensor on Bank 1 can disrupt the circuit.
- Poor electrical connections in the rear heated oxygen sensor circuit can cause low voltage signals.
- Variations in fuel system pressure, either low or high, can affect sensor readings.
- Contaminated fuel can lead to improper combustion and affect sensor performance.
- Faulty fuel injectors may cause incorrect fuel delivery, impacting sensor readings.
- Exhaust gas leaks can introduce false air into the system, affecting sensor output.
- Engine vacuum leaks can alter the air-fuel mixture, leading to incorrect sensor voltage.
How to fix OBD code Error Code P0137?
- Verify DTC Code: Confirm the presence of DTC P0137 using an OBD-II scanner to ensure accurate diagnosis.
- Inspect Wiring and Connectors: Check the wiring and connectors for the O2 sensor Bank 1 Sensor 2 for any signs of damage, corrosion, or disconnection.
- Test Sensor Voltage: Measure the voltage at the O2 sensor connector with a multimeter. A low voltage reading indicates a potential sensor issue.
- Check Exhaust Leaks: Inspect the exhaust system for leaks that could affect the O2 sensor readings and cause a low voltage condition.
- Evaluate Sensor Performance: Use a scan tool to monitor the O2 sensor's performance and compare it to expected values to determine if the sensor is functioning correctly.
- Replace O2 Sensor: If the sensor is faulty, replace the Rear Heated Oxygen Sensor Bank 1 Sensor 2 as it often resolves the issue.
- Clear DTC and Test Drive: Clear the DTC code and perform a test drive to ensure the issue is resolved and the code does not return.