AutoCodes – Generic – C0274

C0274 Code - Excessive Dump/Isolation Time

Quick Answer

The Anti-Lock Brake System (ABS) motor relay built into the Skid Control ECU (Brake Actuator Assembly) supplies the power to the ABS Pump Motor. 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: C0274 indicates Excessive Dump/Isolation Time.
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.

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Code Popularity 7,215

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 Jul 05, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code C0274 Description

The Anti-Lock Brake System (ABS) motor relay built into the Skid Control ECU (Brake Actuator Assembly) supplies the power to the ABS Pump Motor. While the ABS is activated, the Skid Control ECU (Brake Actuator Assembly) turns the motor relay ON and operates the ABS pump motor. If the voltage supplied to the motor relay is below the Diagnostic Trouble Code (DTC) detection threshold due to low voltage from the battery or alternator, these DTCs may be stored.

OBDII Code C0274 - Excessive Dump/Isolation Time - AutoCodes.com — C0274 Code - Excessive Dump/Isolation Time

What does this mean?

What are the Possible Causes of the DTC C0274?

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 C0274?

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

If the C0274 code is combined with other codes, fix other codes first.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the C0274 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 C0274 code?

Need more information on how to fix the C0274 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C0274 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

C0274 Buick — Isolation Valve High Temperature
C0274 Cadillac — Isolation Valve High Temperature
C0274 Chevrolet — Isolation Valve High Temperature
C0274 GMC — Isolation Valve High Temperature
C0274 Lexus — Short to B+ in ABS Motor Relay Circuit
C0274 Scion — Short to B+ in ABS Motor Relay Circuit
C0274 Toyota — Short to B+ in ABS Motor Relay 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 C0274 Code

1. What are the common symptoms of OBDII code C0274 (Excessive Dump/Isolation Time)?

- Common symptoms include the ABS warning light coming on, decreased braking performance, and unusual noises coming from the brakes.

2. What are some possible causes of OBDII code C0274?

- Possible causes include faulty isolation valves, damaged ABS pump motor, hydraulic control unit issues, or wiring/connectivity problems.

3. How do I diagnose OBDII code C0274?

- Diagnosis typically involves using a scan tool to retrieve the code, inspecting the ABS system components, checking for loose or damaged wiring, and performing functional tests on the ABS system.

4. Can I still drive my vehicle with OBDII code C0274 present?

- It is not recommended to drive the vehicle with this code present, as it may compromise the effectiveness of the ABS system and lead to potential safety hazards.

5. How can I repair OBDII code C0274?

- Repair options may include replacing faulty isolation valves, repairing or replacing the ABS pump motor, addressing issues with the hydraulic control unit, or fixing any wiring problems.

6. Are there any DIY tips for fixing OBDII code C0274?

- DIY tips include checking and cleaning electrical connections, inspecting for visible damage in ABS components, and ensuring proper fluid levels in the brake system.

7. How much does it typically cost to repair OBDII code C0274?

- The cost of repair can vary depending on the specific issue causing the code, but it may range from a few hundred to over a thousand dollars, including parts and labor.

8. Can OBDII code C0274 be intermittent?

- Yes, this code can sometimes be intermittent, especially if the underlying issue is related to loose or damaged wiring that may cause intermittent connectivity problems.

9. Will resetting the OBDII code C0274 make it go away permanently?

- Resetting the code may temporarily clear the warning light, but if the underlying issue is not fixed, the code is likely to reappear once the ABS system detects the problem again.

10. Is it necessary to take my vehicle to a mechanic for OBDII code C0274, or can I fix it myself?

- While some DIY troubleshooting and repairs are possible, it is recommended to seek professional help for thorough diagnosis and proper repair of OBDII code C0274 to ensure safety and effectiveness of the ABS system.