AutoCodes – Toyota – P0136 2001 Toyota Corolla

P0136 2001 Toyota Corolla Code - HO2S12 Circuit Malfunction 3ZZ-FE Engine

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 2001 Toyota Corolla indicates HO2S12 Circuit Malfunction 3ZZ-FE Engine.
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 6,361

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 2001 Toyota Corolla 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 2001 Toyota Corolla - HO2S12 Circuit Malfunction 3ZZ-FE Engine - AutoCodes.com — P0136 2001 Toyota Corolla Code - HO2S12 Circuit Malfunction 3ZZ-FE Engine

What does this mean?

What are the Possible Causes of the DTC P0136 2001 Toyota Corolla?

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
EFI relay

How to Fix the DTC P0136 2001 Toyota Corolla?

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 2001 Toyota Corolla 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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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 2001 Toyota Corolla Code

1. What does the OBDII code P0136 indicate for a 2001 Toyota Corolla with the 3ZZ-FE engine?

The code P0136 for a 2001 Toyota Corolla with the 3ZZ-FE engine indicates a malfunction in the HO2S12 (Heated Oxygen Sensor Bank 1 Sensor 2) circuit.

2. What are common symptoms of the HO2S12 circuit malfunction in a 2001 Toyota Corolla?

Common symptoms of the HO2S12 circuit malfunction in a 2001 Toyota Corolla may include poor fuel economy, rough idling, hesitation during acceleration, and an illuminated check engine light.

3. What are the possible causes of the P0136 OBDII code in a 2001 Toyota Corolla?

Possible causes of the P0136 OBDII code in a 2001 Toyota Corolla include a faulty HO2S12 sensor, damaged wiring or connectors in the sensor circuit, exhaust leaks, or issues with the engine's air-fuel mixture.

4. How can I diagnose the HO2S12 circuit malfunction in my 2001 Toyota Corolla?

To diagnose the HO2S12 circuit malfunction in a 2001 Toyota Corolla, you can use an OBDII scanner to read the trouble code, visually inspect the sensor and its wiring for damage, test the sensor's voltage output, and check for exhaust leaks.

5. Can I drive my 2001 Toyota Corolla with the P0136 code?

It is generally not recommended to drive a vehicle with the P0136 code, as it can lead to poor engine performance and potential damage to the catalytic converter. It is best to address the issue promptly.

6. How can I repair the HO2S12 circuit malfunction in my 2001 Toyota Corolla?

Repairing the HO2S12 circuit malfunction in a 2001 Toyota Corolla may involve replacing the HO2S12 sensor, repairing damaged wiring or connectors, fixing any exhaust leaks, and resetting the check engine light with an OBDII scanner.

7. Is the HO2S12 sensor difficult to replace in a 2001 Toyota Corolla?

Replacing the HO2S12 sensor in a 2001 Toyota Corolla is typically a straightforward task that can be done with basic tools. However, access to the sensor may vary depending on the vehicle's specific configuration.

8. How much does it cost to fix the P0136 code in a 2001 Toyota Corolla?

The cost to fix the P0136 code in a 2001 Toyota Corolla can vary depending on the root cause of the issue. Replacing the HO2S12 sensor or repairing wiring may cost between $100 to $300, excluding labor charges.

9. Will resetting the check engine light resolve the P0136 code in my 2001 Toyota Corolla?

Resetting the check engine light may temporarily clear the P0136 code, but it will not fix the underlying issue causing the malfunction. It is essential to diagnose and repair the problem to prevent further complications.

10. Can a P0136 code affect the emissions of my 2001 Toyota Corolla?

Yes, a P0136 code can affect the emissions of a 2001 Toyota Corolla by causing the engine to run inefficiently, potentially leading to increased emissions. It is crucial to address the issue promptly to maintain optimal emissions performance.