P0138 2005 Toyota Prius Code - Oxygen Sensor Circuit High Voltage Bank 1 Sensor 2
Quick Answer
The Heated Oxygen Sensor 2 (HO2S) (Rear O2 Sensor), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. Common causes include Faulty Rear Heated Oxygen Sensor Bank 1, Rear Heated Oxygen Sensor Bank 1 harness is open or shorted, Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection. 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 2005 Toyota Prius indicates Oxygen Sensor Circuit High Voltage Bank 1 Sensor 2.
- Common causes
- Common causes include Faulty Rear Heated Oxygen Sensor Bank 1, Rear Heated Oxygen Sensor Bank 1 harness is open or shorted, Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection.
- 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.
Code P0138 2005 Toyota Prius Description
What are the Possible Causes of the DTC P0138 2005 Toyota Prius?
- Faulty Rear Heated Oxygen Sensor Bank 1
- Rear Heated Oxygen Sensor Bank 1 harness is open or shorted
- Rear Heated Oxygen Sensor Bank 1 circuit poor electrical connection
- Intake air leaks
- Exhaust gas leaks
- Inappropriate fuel pressure
- Faulty fuel injectors
How to Fix the DTC P0138 2005 Toyota Prius?
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 P0138 2005 Toyota Prius 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 P0138 2005 Toyota Prius Code
1. What does the OBDII code P0138 indicate on a 2005 Toyota Prius?
- Code P0138 indicates that the O2 sensor in bank 1 sensor 2 is experiencing high voltage output beyond the normal range, suggesting a malfunction in the oxygen sensor or its circuit.
2. What are common symptoms of code P0138 in a 2005 Toyota Prius?
- Common symptoms include a check engine light, poor fuel economy, rough engine idle, and in some cases, a noticeable sulfur smell from the exhaust.
3. What could cause the OBDII code P0138 to appear on a 2005 Toyota Prius?
- Potential causes include a faulty oxygen sensor, short to voltage in the oxygen sensor signal circuit, exhaust leaks near the sensor, or issues with the engine control module (ECM).
4. How can I fix the OBDII code P0138 in my 2005 Toyota Prius?
- To fix this code, inspect and replace the oxygen sensor if faulty, repair any shorts or opens in the wiring, check for exhaust leaks and repair as necessary, and ensure the ECM is functioning properly.
5. Is it safe to drive my 2005 Toyota Prius with the OBDII code P0138?
- While it may be safe to drive for a short period, prolonged driving with this issue can lead to increased emissions, reduced fuel efficiency, and potential damage to other components like the catalytic converter.
6. How urgent is it to address the OBDII code P0138 in a 2005 Toyota Prius?
- It is moderately urgent to address this code to avoid further complications or damage to the emission system and ensure optimal vehicle performance.
7. What tools are needed to diagnose the cause of code P0138 in a 2005 Toyota Prius?
- Diagnostic tools required include an OBDII scanner, a digital multimeter, and potentially an oscilloscope to check the sensor's waveform output.
8. Can a faulty oxygen sensor causing code P0138 affect the overall performance of the 2005 Toyota Prius?
- Yes, a faulty sensor can lead to suboptimal combustion by providing incorrect data to the ECM, which affects air-fuel mixture and can reduce engine performance and efficiency.
9. How can I prevent the OBDII code P0138 from recurring in my 2005 Toyota Prius?
- Regular maintenance, including checking and replacing oxygen sensors as part of routine service intervals and ensuring that the vehicle's exhaust system is in good condition, can help prevent this issue.
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