AutoCodesMitsubishi – P0143 Mitsubishi

P0143 Mitsubishi Code - Heated Oxygen Sensor Heater Control Circuit Low Voltage Bank 1 Sensor 3

Quick Answer

The rear heated oxygen sensor (or sensor 3 for some vehicles), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. Common causes include Faulty Heated Oxygen Sensor Bank 1 Sensor 3, Heated Oxygen Sensor Bank 1 Sensor 3 harness is open or shorted, Heated Oxygen Sensor Bank 1 Sensor 3 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
P0143 Mitsubishi indicates Heated Oxygen Sensor Heater Control Circuit Low Voltage Bank 1 Sensor 3.
Common causes
Common causes include Faulty Heated Oxygen Sensor Bank 1 Sensor 3, Heated Oxygen Sensor Bank 1 Sensor 3 harness is open or shorted, Heated Oxygen Sensor Bank 1 Sensor 3 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 4,993
How popular is this code, among other codes? Low
Table of contents Created and updated by William Orellana on Jun 14, 2020
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Code P0143 Mitsubishi Description

The rear heated oxygen sensor (or sensor 3 for some vehicles), after three way catalyst (manifold), monitors the oxygen level in the exhaust gas on each bank. Even if switching characteristics of the heated oxygen sensor 1 are shifted, the air-fuel ratio is controlled to stoichiometric, by the signal from the heated oxygen sensor 3.
This sensor is made of ceramic zirconia. The zirconia generates voltage from approximately 1V in richer conditions to 0V in leaner conditions. Under normal conditions the heated oxygen sensor 3 is not used for engine control operation.
OBDII Code P0143 Mitsubishi - Heated Oxygen Sensor Heater Control Circuit Low Voltage Bank 1 Sensor 3 - AutoCodes.com
P0143 Mitsubishi Code - Heated Oxygen Sensor Heater Control Circuit Low Voltage Bank 1 Sensor 3

What are the Possible Causes of the DTC P0143 Mitsubishi?

  • Faulty Heated Oxygen Sensor Bank 1 Sensor 3
  • Heated Oxygen Sensor Bank 1 Sensor 3 harness is open or shorted
  • Heated Oxygen Sensor Bank 1 Sensor 3 circuit poor electrical connection

How to Fix the DTC P0143 Mitsubishi?

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 P0143 Mitsubishi 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 P0143 Mitsubishi 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 P0143 Mitsubishi Code

What does the OBDII code P0143 indicate on a Mitsubishi?

P0143 indicates a low voltage issue in the heater control circuit for the heated oxygen sensor located at Bank 1, Sensor 3.

What are the common symptoms of code P0143 in a Mitsubishi?

Symptoms may include poor fuel efficiency, rough engine performance, increased emissions, and an illuminated check engine light.

What causes the P0143 code to occur?

Common causes include a faulty oxygen sensor, damaged wiring, poor electrical connections, or a malfunctioning heater control circuit.

Can I drive my Mitsubishi with the P0143 code?

While the car may still be drivable, it’s not recommended due to potential engine performance issues and increased emissions.

How is the P0143 code diagnosed?

A mechanic will use a scan tool to confirm the code, inspect the oxygen sensor, check the wiring and connectors, and test the heater control circuit for proper function.

What is the role of Bank 1 Sensor 3 in a Mitsubishi?

Bank 1 Sensor 3 is typically located downstream in the exhaust system and helps monitor emissions and catalytic converter efficiency.

How can I fix the P0143 code on my Mitsubishi?

Repairs may involve replacing the faulty oxygen sensor, repairing damaged wiring, or addressing issues with the heater control circuit.

How much does it cost to fix the P0143 code in a Mitsubishi?

Repair costs vary, but replacing an oxygen sensor typically costs $150-$300, plus labor. Wiring repairs may cost less depending on complexity.

What tools are needed to address the P0143 code?

You’ll need a scan tool to confirm the code, a multimeter to test wiring and voltage, and basic hand tools to replace the sensor if necessary.

How can I prevent the P0143 code from reoccurring?

Regular maintenance, inspecting wiring for damage, and replacing oxygen sensors as needed can help prevent this code.

Discuss the causes and fixes for P0143 Mitsubishi OBDII Code

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