P0138 2015 GMC Sierra Code - HO2S Circuit High Voltage Bank 1 Sensor 2
Quick Answer
The P0138 diagnostic trouble code (DTC) for a 2015 GMC Sierra refers to a problem with the HO2S (Heated Oxygen Sensor) Circuit High Voltage for Bank 1 Sensor 2. Common causes include Faulty oxygen sensor, Wiring issues such as frayed or damaged wires, ECM malfunction. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
- What it means
- P0138 2015 GMC Sierra indicates HO2S Circuit High Voltage Bank 1 Sensor 2.
- Common causes
- Common causes include Faulty oxygen sensor, Wiring issues such as frayed or damaged wires, ECM malfunction.
- Severity
- Moderate - service should be scheduled soon.
- Can I drive?
- The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.
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Code P0138 2015 GMC Sierra Description
The P0138 diagnostic trouble code (DTC) for a 2015 GMC Sierra refers to a problem with the HO2S (Heated Oxygen Sensor) Circuit High Voltage for Bank 1 Sensor 2. This sensor is located downstream of the catalytic converter and is responsible for monitoring the oxygen content in the exhaust gases. The sensor sends signals to the engine control module (ECM) to adjust the air-fuel mixture for optimal combustion.
Common Causes of P0138 2015 GMC Sierra
- Faulty oxygen sensor
- Wiring issues such as frayed or damaged wires
- ECM malfunction
- Exhaust leaks near the sensor
- Contaminated sensor due to oil or coolant leaks
Symptoms of P0138 2015 GMC Sierra
- Check engine light illuminated
- Decreased fuel efficiency
- Rough idling or stalling
- Engine misfires
- Increased emissions
How to Fix P0138 2015 GMC Sierra
- Begin by diagnosing the specific cause of the high voltage reading, which may involve using a scan tool to monitor sensor data and check for any related trouble codes.
- Inspect the wiring harness and connections for any signs of damage or corrosion. Repair or replace any damaged wires.
- Test the oxygen sensor using a multimeter to determine if it is functioning correctly. Replace the sensor if necessary.
- Clear the DTC and reset the ECM to see if the code returns after repairs have been made.
- Perform a road test to ensure that the vehicle is running properly and that the check engine light remains off.
Cost to Fix P0138 2015 GMC Sierra
The cost of repairing a P0138 code on a 2015 GMC Sierra can vary depending on the specific cause of the issue. On average, the cost of replacing an oxygen sensor ranges from $200 to $300, including parts and labor. However, if additional repairs are needed, such as fixing wiring issues or replacing the ECM, the total cost could be higher. It's important to consult with a qualified mechanic to get an accurate estimate based on the specific circumstances of your vehicle. Keep in mind that labor rates at auto repair shops can vary, so it's advisable to check local rates for a more precise estimate.
Tech Notes for P0138 2015 GMC Sierra
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