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Engine-Codes – Infiniti – B142A Infiniti

B142A Infiniti Code - Ignition Voltage

Quick Answer

The diagnostic code B142A indicates an issue related to the ignition voltage supplied to the Airbag Diagnosis Sensor Unit, which is critical for the proper functioning of the vehicle's airbag system. Common causes include Faulty Airbag Diagnosis Sensor UnitOpen or shorted wiring harness connected to the Airbag Diagnosis Sensor UnitPoor electrical connections within the Airbag Diagnosis Sensor Unit circuitFaulty ignition switch affecting voltage supplyElectrical interference from other components or systems in the vehicle. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
B142A Infiniti indicates Ignition Voltage.
Common causes
Common causes include Faulty Airbag Diagnosis Sensor UnitOpen or shorted wiring harness connected to the Airbag Diagnosis Sensor UnitPoor electrical connections within the Airbag Diagnosis Sensor Unit circuitFaulty ignition switch affecting voltage supplyElectrical interference from other components or systems in the vehicle.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
What is this?
Table of contents Created and updated by William Orellana on Nov 10, 2025
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Code B142A Infiniti Description

The diagnostic code B142A indicates an issue related to the ignition voltage supplied to the Airbag Diagnosis Sensor Unit, which is critical for the proper functioning of the vehicle's airbag system. The Airbag Diagnosis Sensor Unit, also referred to as the Airbag Control Module or Electronic Crash Unit, plays a vital role in monitoring the vehicle's safety systems. It continuously assesses data from various collision sensors and determines whether the conditions warrant airbag deployment in the event of a crash. When the ignition is turned to the ON position, the unit receives the necessary voltage to operate. If the voltage is too low or too high, it can trigger the B142A code, indicating a malfunction in the ignition voltage supply.
OBDII Code B142A Infiniti - Ignition Voltage
B142A Infiniti Code - Ignition Voltage

Common Causes of B142A Infiniti

  1. Faulty Airbag Diagnosis Sensor Unit
  2. Open or shorted wiring harness connected to the Airbag Diagnosis Sensor Unit
  3. Poor electrical connections within the Airbag Diagnosis Sensor Unit circuit
  4. Faulty ignition switch affecting voltage supply
  5. Electrical interference from other components or systems in the vehicle

Symptoms of B142A Infiniti

  1. Air Bag Warning Light ON
  2. Engine Light ON (or Service Engine Soon Warning Light)
  3. Intermittent airbag deployment issues
  4. Inconsistent performance of other electrical systems
  5. Diagnostic trouble codes related to airbag system stored in the ECU

How to Fix B142A Infiniti

  1. Perform a visual inspection of the Airbag Diagnosis Sensor Unit and its wiring harness for any signs of damage or corrosion.
  2. Test the voltage supply to the Airbag Diagnosis Sensor Unit with a multimeter to ensure it is within the manufacturer's specified range.
  3. If the voltage is outside the acceptable range, check the ignition switch and associated wiring for faults.
  4. Replace any damaged wiring or connectors, and if necessary, replace the Airbag Diagnosis Sensor Unit.
  5. Clear the diagnostic trouble codes and perform a system reset to ensure proper functionality of the airbag system.

Cost to Fix B142A Infiniti

The cost to diagnose and repair the B142A code can vary significantly based on the specific issue identified. Typical parts and labor costs range from $150 to $600, depending on whether the Airbag Diagnosis Sensor Unit needs replacement or if wiring repairs are necessary. Labor rates typically range from $80 to $150 per hour, with dealerships generally charging more than independent shops. The total cost may also be influenced by the vehicle's make and model, as well as the local labor market.

Need more information about the B142A Infiniti code?

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Precautions for SRS “AIR BAG” and “SEAT BELT PRE-TENSIONER” Service

  • Never probe the electrical connectors on air bag, side air curtain modules or seat belts.
  • Never disassemble or tamper with safety belt buckle/retractor pretensioners, adaptive load limiting retractors, safety belt inflators, or probe the electrical connectors.
  • Do not use electrical test equipment to check SRS circuits unless instructed to in this Service Manual.
  • Before servicing the SRS, turn ignition switch OFF, disconnect both battery cables and wait at least 3 minutes. For approximately 3 minutes after the cables are removed, it is still possible for the air bag and seat belt pre-tensioner to deploy. Therefore, do not work on any SRS connectors or wires until at least 3 minutes have passed.

Failure to follow this instruction may result in the accidental deployment of these modules, which increases the risk of serious personal injury or death.

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 B142A Infiniti Code

1. What are the common symptoms of OBDII code B142A in Infiniti vehicles?

The common symptoms include issues with starting the vehicle, rough idling, and a lit check engine light on the dashboard.

2. What does the OBDII code B142A in an Infiniti indicate?

This code specifically points to a problem with the ignition voltage in the vehicle.

3. What are some possible causes of OBDII code B142A in an Infiniti?

Potential causes include a faulty ignition switch, damaged wiring, or a weak battery.

4. How can I diagnose the issue causing OBDII code B142A in my Infiniti?

It is recommended to use a diagnostic scanner to read the code and perform a thorough inspection of the ignition system components.

5. Can a weak battery trigger OBDII code B142A in an Infiniti?

Yes, a weak or failing battery can lead to issues with ignition voltage and trigger this specific OBDII code.

6. How can I repair OBDII code B142A in my Infiniti?

Repairing this code often involves fixing or replacing the faulty ignition switch, repairing damaged wiring, or replacing the battery if necessary.

7. Is it safe to continue driving with OBDII code B142A present in my Infiniti?

It is not recommended to drive the vehicle with this code present, as it may lead to further electrical issues or potential stalling while driving.

8. Can OBDII code B142A in an Infiniti be reset without fixing the underlying issue?

While you can clear the code temporarily, it is essential to address the root cause to prevent it from reoccurring and potentially causing more significant problems.

9. Are there any preventive maintenance tips to avoid OBDII code B142A in an Infiniti?

Regularly inspecting the ignition system components, ensuring the battery is in good condition, and addressing any electrical issues promptly can help prevent this code from appearing.

10. Should I seek professional help to diagnose and repair OBDII code B142A in my Infiniti?

If you are not experienced in automotive repair, it is advisable to consult a professional mechanic who can accurately diagnose and repair the issue causing the OBDII code B142A in your Infiniti.

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