AutoCodes – Toyota – P0136 2007 Toyota Prius

P0136 2007 Toyota Prius Code - HO2S12 Circuit Malfunction

Quick Answer

The heated oxygen sensor 2 (HO2S), 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: P0136 2007 Toyota Prius indicates HO2S12 Circuit Malfunction.
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.

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Code Popularity 6,309

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Jun 14, 2020

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code P0136 2007 Toyota Prius Description

The heated oxygen sensor 2 (HO2S), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. For optimum catalyst operation, the air fuel mixture (air-fuel ratio) must be maintained near the ideal stoichiometric ratio. The HO2S output voltage changes suddenly in the vicinity of the stoichiometric ratio. The Engine Control Module (ECM) adjusts the fuel injection time so that the air-fuel ratio is nearly stoichiometric. The HO2S generates a voltage between 0.1 and 0.9 V in response to oxygen in the exhaust gas. If the oxygen in the exhaust gas increases, the air-fuel ratio becomes Lean. The ECM interprets Lean when the HO2S voltage is below 0.45 V. If the oxygen in the exhaust gas decreases, the air-fuel ratio becomes Rich. The ECM interprets Rich when the HO2S voltage is above 0.45 V.

OBDII Code P0136 2007 Toyota Prius - HO2S12 Circuit Malfunction - AutoCodes.com — P0136 2007 Toyota Prius Code - HO2S12 Circuit Malfunction

What does this mean?

What are the Possible Causes of the DTC P0136 2007 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
Inappropriate fuel pressure
Faulty fuel injectors
Intake air leaks may be faulty
Exhaust gas leaks

How to Fix the DTC P0136 2007 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 does this mean?

Code Tech Notes

Replacing the Rear Heated Oxygen Sensor Bank 1 usually takes care of the problem.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0136 2007 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.

Need more information about the P0136 2007 Toyota Prius code?

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About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0136 2007 Toyota Prius Code

1. What does OBDII code P0136 for a 2007 Toyota Prius mean?

The code P0136 indicates a malfunction in the HO2S12 (heated oxygen sensor bank 1 sensor 2) circuit.

2. What are common symptoms of a HO2S12 circuit malfunction in a 2007 Toyota Prius?

Common symptoms include poor fuel efficiency, rough idling, engine hesitation, and the illumination of the check engine light.

3. What are possible causes of the P0136 code in a 2007 Toyota Prius?

Possible causes include a faulty oxygen sensor, damaged wiring or connectors in the sensor circuit, exhaust leaks, or issues with the engine control module (ECM).

4. How can I diagnose the HO2S12 circuit malfunction in my 2007 Toyota Prius?

Diagnosing the issue usually involves using an OBDII scanner to read the code, inspecting the oxygen sensor and its connections, checking for exhaust leaks, and testing the sensor's voltage output.

5. Can I drive my 2007 Toyota Prius with the P0136 code?

It is generally not recommended to drive with the P0136 code as it can lead to decreased fuel efficiency and potential damage to the catalytic converter over time.

6. How can I repair the HO2S12 circuit malfunction in my 2007 Toyota Prius?

Repair options may include replacing the oxygen sensor, repairing damaged wiring or connectors, fixing exhaust leaks, or resetting the ECM after addressing any underlying issues.

7. Will resetting the check engine light resolve the P0136 code in my 2007 Toyota Prius?

Resetting the check engine light may temporarily clear the code, but if the underlying issue causing the malfunction is not addressed, the code is likely to reappear.

8. How much does it typically cost to fix the P0136 code in a 2007 Toyota Prius?

The cost of fixing the P0136 code can vary depending on the cause of the issue, but it may range from $100 to $300 for parts and labor.

9. Is it possible to prevent the HO2S12 circuit malfunction in my 2007 Toyota Prius?

While some causes of the P0136 code may be unavoidable, regular maintenance, timely repairs, and addressing any engine issues promptly can help prevent the recurrence of this code.

10. Can I use a universal oxygen sensor as a replacement for the HO2S12 in my 2007 Toyota Prius?

It is recommended to use an OEM or compatible oxygen sensor specifically designed for your Toyota Prius to ensure proper fit and performance when replacing the HO2S12 sensor.