P0139 GMC Code - HO2S Slow Response Bank 1 Sensor 2
Quick Answer
The Powertrain Control Module (PCM) provides a .45 volt reference signal to the Heated Oxygen Sensor (HO2S) through the Bank 1 high signal circuit. Common causes include Faulty Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2, HO2S Bank 1 Sensor 2 harness is open or shorted, HO2S Bank 1 Sensor 2circuit poor electrical connection. 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
- P0139 GMC indicates HO2S Slow Response Bank 1 Sensor 2.
- Common causes
- Common causes include Faulty Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2, HO2S Bank 1 Sensor 2 harness is open or shorted, HO2S Bank 1 Sensor 2circuit poor electrical connection.
- 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.
Code P0139 GMC Description
What are the Possible Causes of the DTC P0139 GMC?
- Faulty Heated Oxygen Sensor (HO2S) Bank 1 Sensor 2
- HO2S Bank 1 Sensor 2 harness is open or shorted
- HO2S Bank 1 Sensor 2circuit poor electrical connection
How to Fix the DTC P0139 GMC?
Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0139 GMC code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.
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Frequently Asked Questions about P0139 GMC Code
1. What are common symptoms of OBDII code P0139 in a GMC vehicle?
- Common symptoms include poor fuel economy, rough idling, engine hesitation, and the illumination of the check engine light.
2. What does the OBDII code P0139 "HO2S Slow Response Bank 1 Sensor 2" mean for a GMC vehicle?
- This code indicates that the oxygen sensor (O2 sensor) located after the catalytic converter on bank 1 is not responding as quickly as expected.
3. What are the possible causes of OBDII code P0139 in a GMC vehicle?
- Potential causes include a faulty oxygen sensor, wiring issues, exhaust system leaks, engine misfires, or problems with the catalytic converter.
4. How can I diagnose the cause of OBDII code P0139 in my GMC vehicle?
- Diagnosing this code typically involves checking the oxygen sensor's wiring and connections, performing a visual inspection of the exhaust system, and testing the sensor's response using a scan tool.
5. What are some repair tips for addressing OBDII code P0139 in a GMC vehicle?
- Repair tips may include replacing the oxygen sensor, repairing any wiring issues, fixing exhaust leaks, addressing engine misfires, or replacing the catalytic converter if necessary.
6. Can I continue driving my GMC vehicle with OBDII code P0139 present?
- While the vehicle may still be operable with this code, it is recommended to address the issue promptly to prevent potential damage to the engine or catalytic converter.
7. How much does it typically cost to repair OBDII code P0139 in a GMC vehicle?
- Repair costs can vary depending on the exact cause of the code, but expenses may include the cost of a new oxygen sensor, wiring repairs, or other necessary parts and labor.
8. Will resetting the check engine light make OBDII code P0139 go away permanently?
- Resetting the check engine light may temporarily clear the code, but if the underlying issue is not addressed, the code is likely to reappear after driving the vehicle for a while.
9. Is it possible to prevent OBDII code P0139 from occurring in my GMC vehicle?
- Regular maintenance, such as replacing oxygen sensors at recommended intervals, addressing engine performance issues promptly, and keeping the exhaust system in good condition, can help prevent this code from appearing.
10. Can OBDII code P0139 cause any long-term damage to my GMC vehicle if left unresolved?
- Ignoring this code may lead to decreased fuel efficiency, increased emissions, potential damage to the catalytic converter, and overall decreased engine performance over time.
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