AutoCodes – Subaru – C0042 Subaru

C0042 Subaru Code - Power Supply Voltage Failure

Quick Answer

The Anti-Lock Brake System (ABS) Module monitors the Power Supply Voltage. Common causes include Power Supply Voltage harness is open or shorted, Power Supply Voltage circuit poor electrical connection. 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: C0042 Subaru indicates Power Supply Voltage Failure.
Common causes: Common causes include Power Supply Voltage harness is open or shorted, Power Supply Voltage circuit poor electrical connection.
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.

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Code Popularity 34,625

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on May 02, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code C0042 Subaru Description

The Anti-Lock Brake System (ABS) Module monitors the Power Supply Voltage. The ABS Module sets the OBDII code when the Power Supply Voltage is not to factory specifications.

OBDII Code C0042 Subaru - Power Supply Voltage Failure - AutoCodes.com — C0042 Subaru Code - Power Supply Voltage Failure

What does this mean?

What are the Possible Causes of the DTC C0042 Subaru?

Power Supply Voltage harness is open or shorted
Power Supply Voltage circuit poor electrical connection

How to Fix the DTC C0042 Subaru?

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 C0042 Subaru 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 C0042 Subaru code?

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Need Help with the 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 C0042 Subaru Code

1. What are the common symptoms of OBDII code C0042 in a Subaru related to power supply voltage failure?

- Common symptoms include issues with power steering operation, ABS system malfunctions, and dashboard warning lights illuminating.

2. What are the possible causes of OBDII code C0042 in a Subaru indicating power supply voltage failure?

- The code C0042 in a Subaru may be triggered by a faulty ABS actuator, damaged wiring harness, or a malfunctioning electronic control unit (ECU).

3. How can I diagnose the OBDII code C0042 in my Subaru related to power supply voltage failure?

- Diagnosis involves using a scan tool to retrieve the code, inspecting the ABS system components, and testing the power supply voltage to identify the root cause.

4. Can a DIY enthusiast repair OBDII code C0042 in a Subaru caused by power supply voltage failure?

- Repairing this code typically requires specialized knowledge and tools, so it is recommended to seek professional help to resolve the issue effectively.

5. Are there any safety concerns associated with OBDII code C0042 in a Subaru due to power supply voltage failure?

- Yes, unresolved power supply voltage issues can affect the proper functioning of critical safety systems like ABS and power steering, potentially compromising vehicle safety.

6. Is it possible for other codes to be triggered along with OBDII code C0042 in a Subaru indicating power supply voltage failure?

- Yes, related codes such as ABS system fault codes or communication errors with other control modules may also be present when code C0042 is detected.

7. How long does it typically take to repair OBDII code C0042 in a Subaru caused by power supply voltage failure?

- The repair time can vary depending on the exact cause of the issue, but it may take a few hours to a day for a professional technician to diagnose and rectify the problem.

8. Can a weak car battery cause OBDII code C0042 in a Subaru related to power supply voltage failure?

- Yes, a weak or failing car battery can lead to voltage fluctuations that may trigger code C0042, so it's essential to ensure the battery is in good condition.

9. Are there any preventative measures to avoid encountering OBDII code C0042 in a Subaru due to power supply voltage failure?

- Maintaining a regular schedule of vehicle inspections and addressing any electrical issues promptly can help prevent power supply voltage failures that trigger code C0042.

10. Will driving with OBDII code C0042 in a Subaru caused by power supply voltage failure damage other vehicle components?

- Continuing to drive with this code present may lead to further damage to the ABS system components or electronic control unit, so it's best to address the issue promptly.