P0139 Buick 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 Buick 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 Buick Description
What are the Possible Causes of the DTC P0139 Buick?
- 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 Buick?
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 Buick 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 Buick Code
1. What does the OBDII code P0139 mean for a Buick?
P0139 indicates that the oxygen sensor (HO2S) on Bank 1 Sensor 2 is responding slower than expected by the engine control module (ECM).
2. What are the common symptoms of code P0139 in a Buick?
Symptoms may include a check engine light, reduced fuel efficiency, rough idling, and increased emissions.
3. What causes the P0139 code to appear?
Common causes include a faulty downstream oxygen sensor, exhaust leaks, wiring issues, or contamination of the sensor from oil or coolant.
4. Which oxygen sensor is Bank 1 Sensor 2 on a Buick?
Bank 1 Sensor 2 is the downstream sensor located after the catalytic converter on the side of the engine with cylinder 1.
5. Can a dirty or clogged catalytic converter trigger a P0139 code?
Yes, a clogged or inefficient catalytic converter can affect sensor readings and contribute to this code.
6. How do you fix the P0139 code on a Buick?
Repairs may involve replacing the oxygen sensor, repairing wiring or connectors, fixing exhaust leaks, or addressing issues with the catalytic converter.
7. Can I drive my Buick with a P0139 code?
While the vehicle may still be drivable, prolonged driving with this code can reduce performance and increase emissions, potentially causing further damage.
8. How do you diagnose a P0139 code in a Buick?
Diagnosis involves using an OBDII scanner, checking live sensor data, inspecting the sensor and wiring, and testing for exhaust leaks or catalytic converter issues.
9. Is a P0139 code likely to cause my Buick to fail an emissions test?
Yes, this code can lead to increased emissions, which may result in failing an emissions test.
10. How much does it typically cost to repair a P0139 code on a Buick?
Repair costs vary but may range from $150 to $400, depending on whether the oxygen sensor or other components need replacement.
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