P1139 GMC Code - HO2S Insufficient Switching Bank 1 Sensor 2
Quick Answer
The P1139 GMC code indicates an issue with the HO2S (heated oxygen sensor) insufficient switching on Bank 1 Sensor 2 in the vehicle's exhaust system. Common causes include Faulty HO2S, Wiring or connector issues, Exhaust leaks. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
- What it means
- P1139 GMC indicates HO2S Insufficient Switching Bank 1 Sensor 2.
- Common causes
- Common causes include Faulty HO2S, Wiring or connector issues, Exhaust leaks.
- Severity
- High - diagnose this code as soon as possible.
- Can I drive?
- Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code P1139 GMC Description
The P1139 GMC code indicates an issue with the HO2S (heated oxygen sensor) insufficient switching on Bank 1 Sensor 2 in the vehicle's exhaust system. The HO2S is responsible for measuring the oxygen content in the exhaust gases and sending this information to the engine control module (ECM) to adjust the air-fuel mixture for optimal combustion. When the sensor does not switch between rich and lean conditions as expected, it can lead to a variety of performance issues.
Common Causes of P1139 GMC
- Faulty HO2S
- Wiring or connector issues
- Exhaust leaks
- Malfunctioning ECM
- Contaminated sensor due to oil or coolant leaks
Symptoms of P1139 GMC
- Decreased fuel efficiency
- Rough idling
- Hesitation during acceleration
- Increased emissions
- Engine misfires
How to Fix P1139 GMC
- Diagnostic: Use a scan tool to retrieve the fault code and perform a thorough inspection of the HO2S, wiring, and connectors to identify the root cause of the issue.
- Replace HO2S: If the sensor is faulty, replace it with a new one following the manufacturer's specifications.
- Repair wiring/connectors: Repair any damaged wiring or connectors and ensure proper connections for the HO2S.
- Check for exhaust leaks: Inspect the exhaust system for any leaks that could be affecting the sensor's readings.
- Test and clear codes: After completing the repair, test the vehicle to ensure proper functionality and clear the fault code from the ECM.
Cost to Fix P1139 GMC
The cost of repairing a HO2S insufficient switching code can vary depending on the specific cause of the issue. On average, the cost of replacing a heated oxygen sensor can range from $100 to $300, including parts and labor. Additional costs may apply if there are wiring or connector repairs needed. It is advisable to consult with a professional mechanic to get an accurate estimate based on the specific vehicle make and model. Labor rates can vary between $80 and $150 per hour, so it's essential to factor in this cost as well.
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