P0138 2015 Toyota RAV4 Code - Oxygen Sensor Circuit High Voltage Bank 1 Sensor 2
Quick Answer
In order to obtain a high purification rate of the Carbon Monoxide (CO), Hydrocarbon (HC), and Nitrogen Oxide (NOx) components in the exhaust gas, a Three-Way Catalytic Converter (TWC) is used. Common causes include Faulty Oxygen Sensor Bank 1 Sensor 2, Oxygen Sensor Bank 1 Sensor 2 harness is open or shorted, Oxygen Sensor Bank 1 Sensor 2 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 2015 Toyota RAV4 indicates Oxygen Sensor Circuit High Voltage Bank 1 Sensor 2.
- Common causes
- Common causes include Faulty Oxygen Sensor Bank 1 Sensor 2, Oxygen Sensor Bank 1 Sensor 2 harness is open or shorted, Oxygen Sensor Bank 1 Sensor 2 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 2015 Toyota RAV4 Description
The heated oxygen sensor is located behind the TWC and detects the oxygen concentration in the exhaust gas. Since the sensor is integrated with the heater that heats the sensing portion, it is possible to detect the oxygen concentration even when the intake air volume is low (the exhaust gas temperature is low).
When the air-fuel ratio becomes lean, the oxygen concentration in the exhaust gas is high. The heated oxygen sensor informs the ECM that the post-TWC air-fuel ratio is lean (low voltage, i.e. less than 0.45 V).
Conversely, when the air-fuel ratio is richer than the stoichiometric air-fuel level, the oxygen concentration in the exhaust gas is low. The heated oxygen sensor informs the ECM that the post-TWC air-fuel ratio is rich (high voltage, i.e. more than 0.45 V). The heated oxygen sensor has the property of changing its output voltage drastically when the air-fuel ratio is close to the stoichiometric level.
The ECM uses the supplementary information from the heated oxygen sensor to determine whether the air-fuel ratio after the TWC is rich or lean and adjusts the fuel injection duration accordingly. Thus, if the heated oxygen sensor is working improperly due to internal malfunctions, the ECM is unable to compensate for deviations in the primary air-fuel ratio control.
The ECM continuously monitors the heated oxygen sensor output voltage while the engine is running. The Diagnostic Trouble Code (DTC) P0138 is stored if the heated oxygen sensor voltage output is 1.2 V or higher for 10 seconds or more.
What are the Possible Causes of the DTC P0138 2015 Toyota RAV4?
- Faulty Oxygen Sensor Bank 1 Sensor 2
- Oxygen Sensor Bank 1 Sensor 2 harness is open or shorted
- Oxygen Sensor Bank 1 Sensor 2 circuit poor electrical connection
- Gas leak from exhaust system
How to Fix the DTC P0138 2015 Toyota RAV4?
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.
Code Tech Notes
What is the Cost to Diagnose the Code?
Labor: 1.0
To diagnose the P0138 2015 Toyota RAV4 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 2015 Toyota RAV4 Code
What does the OBDII code P0138 mean for a 2015 Toyota RAV4?
The P0138 code indicates high voltage in the oxygen sensor circuit for Bank 1 Sensor 2, typically caused by issues with the downstream oxygen sensor or related components.
What are the common symptoms of code P0138 in a 2015 Toyota RAV4?
Symptoms may include a check engine light, reduced fuel efficiency, rough idle, higher emissions, or poor engine performance.
What causes the P0138 code on a 2015 Toyota RAV4?
Common causes include a faulty downstream oxygen sensor, damaged wiring or connectors, exhaust leaks, or a malfunctioning catalytic converter.
Can I drive my 2015 Toyota RAV4 with the P0138 code?
While driving with this code may not cause immediate damage, prolonged driving can lead to reduced fuel efficiency and potential damage to the catalytic converter.
How do I diagnose the P0138 code in a 2015 Toyota RAV4?
Start by inspecting the downstream oxygen sensor, wiring, and connectors for damage. Use a multimeter to check voltage levels and scan live data with an OBDII tool.
How is the P0138 code fixed on a 2015 Toyota RAV4?
Repairs typically involve replacing the faulty downstream oxygen sensor, repairing damaged wiring, or addressing exhaust system issues.
How much does it cost to fix the P0138 code on a 2015 Toyota RAV4?
Replacing the oxygen sensor usually costs $150-$300, including parts and labor. Wiring repairs can vary based on the extent of damage.
Can a dirty air filter cause the P0138 code on a 2015 Toyota RAV4?
A dirty air filter is unlikely to directly cause this code, but it can impact overall engine performance and oxygen sensor readings.
How can I prevent the P0138 code on my 2015 Toyota RAV4?
Regular maintenance, including inspecting oxygen sensors, wiring, and the exhaust system, can help prevent this issue from occurring.
Will clearing the P0138 code fix the problem on a 2015 Toyota RAV4?
Clearing the code may temporarily turn off the check engine light, but the underlying issue must be repaired to prevent the code from returning.
Discuss the causes and fixes for P0138 2015 Toyota RAV4 OBDII Code
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