AutoCodes – Generic – C142B

C142B Code - Motor Power Supply Voltage Circuit

Quick Answer

The Motor Relay and motor fail-safe relay are built into the Brake Actuator Assembly. Common causes include Faulty Skid Control ECU (Brake Actuator Assembly), Skid Control ECU harness is open or shorted, Skid Control ECU 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: C142B indicates Motor Power Supply Voltage Circuit.
Common causes: Common causes include Faulty Skid Control ECU (Brake Actuator Assembly), Skid Control ECU harness is open or shorted, Skid Control ECU 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 589

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 Sep 30, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code C142B Description

The Motor Relay and motor fail-safe relay are built into the Brake Actuator Assembly. During ABS, TRAC, VSC, brake hold, or brake assist operation, the Skid Control ECU (Brake Actuator Assembly) turns on the motor relay to run the pump motor in the Brake Actuator Assembly. When a motor system Diagnostic Trouble Code (DTC) is stored, the motor fail-safe relay cuts the power source supply to the motor relay for fail-safe operation.
This DTC may be stored when the voltage to the motor relay power source is lower than the DTC detection condition due to low output from the battery or alternator.

OBDII Code C142B - Motor Power Supply Voltage Circuit - AutoCodes.com — C142B Code - Motor Power Supply Voltage Circuit

What does this mean?

What are the Possible Causes of the DTC C142B?

Faulty Skid Control ECU (Brake Actuator Assembly)
Skid Control ECU harness is open or shorted
Skid Control ECU circuit poor electrical connection

How to Fix the DTC C142B?

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 C142B 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 C142B code?

Need more information on how to fix the C142B code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C142B code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

C142B Lexus — Motor Power Supply Voltage Circuit
C142B Scion — Motor Power Supply Voltage Circuit
C142B Toyota — Motor Power Supply Voltage Circuit

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 C142B Code

1. What does the OBDII code C142B mean?

C142B indicates an issue with the motor power supply voltage circuit, which may involve low or abnormal voltage levels detected by the vehicle's control module.

2. What are the common symptoms of the C142B code?

Symptoms may include ABS or traction control warning lights, a malfunctioning ABS system, or reduced braking performance.

3. What causes the C142B code to appear?

Common causes include a faulty motor power supply relay, damaged wiring or connectors, a weak battery, or a malfunctioning ABS control module.

4. Can a weak battery trigger the C142B code?

Yes, a weak or failing battery can cause voltage irregularities, leading to the C142B code.

5. How do I diagnose the C142B code?

Start by checking the battery voltage, inspecting the wiring and connectors in the motor power supply circuit, and testing the motor power supply relay.

6. Can I drive with the C142B code active?

While the vehicle may still be drivable, it's not recommended as the ABS and traction control systems may not function properly, increasing the risk of accidents.

7. How do I fix the C142B code?

Repairs may include replacing a faulty motor power supply relay, repairing damaged wiring, or replacing the ABS control module if necessary.

8. How much does it cost to repair the C142B code?

Repair costs vary but typically range from $100 to $500, depending on the specific component that needs replacement or repair.

9. Can a blown fuse cause the C142B code?

Yes, a blown fuse in the motor power supply circuit can disrupt voltage and trigger the C142B code.

10. Do I need professional help to fix the C142B code?

If you're experienced with automotive electrical systems, you may troubleshoot and repair the issue yourself. Otherwise, it's best to consult a professional technician.