P0138 2016 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 2016 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 2016 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 2016 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 2016 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 2016 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 2016 Toyota RAV4 Code
What does the OBDII code P0138 mean on a 2016 Toyota RAV4?
P0138 indicates that the oxygen sensor (Bank 1, Sensor 2) has detected a higher-than-expected voltage, suggesting a possible fault in the sensor or the circuit.
What is Bank 1, Sensor 2 in a 2016 Toyota RAV4?
Bank 1 refers to the side of the engine with cylinder 1, and Sensor 2 is the downstream oxygen sensor located after the catalytic converter.
What are the common symptoms of the P0138 code in a 2016 Toyota RAV4?
Symptoms may include a check engine light, decreased fuel efficiency, rough idling, or a strong fuel smell from the exhaust.
What causes the P0138 code to appear in a 2016 Toyota RAV4?
Potential causes include a faulty oxygen sensor, damaged wiring or connectors, a short circuit, or issues with the vehicle’s ECM.
Can I drive my 2016 Toyota RAV4 with the P0138 code?
While the vehicle may still run, driving with this code can lead to increased emissions, lower fuel efficiency, and potential damage to the catalytic converter.
How do I diagnose the P0138 code on my 2016 Toyota RAV4?
Use an OBDII scanner to confirm the code, inspect the oxygen sensor wiring and connectors, and test the downstream oxygen sensor for proper voltage readings.
How do I fix the P0138 code on a 2016 Toyota RAV4?
Repairs may include replacing the downstream oxygen sensor, repairing damaged wiring, or addressing any underlying issues with the ECM.
How much does it cost to fix the P0138 code on a 2016 Toyota RAV4?
Replacing an oxygen sensor typically costs between $150 and $300, including parts and labor, though costs may vary based on location and mechanic rates.
Can a bad catalytic converter trigger the P0138 code on a 2016 Toyota RAV4?
Yes, a failing catalytic converter can cause abnormal oxygen sensor readings, potentially triggering the P0138 code.
How can I prevent the P0138 code from recurring on my 2016 Toyota RAV4?
Regular maintenance, including checking and replacing oxygen sensors as needed, inspecting wiring, and using high-quality fuel, can help prevent this code.
Discuss the causes and fixes for P0138 2016 Toyota RAV4 OBDII Code
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