AutoCodes – Cadillac – C0266 Cadillac

C0266 Cadillac Code - EBCM Motor Relay Circuit High When Off

Quick Answer

The ABS relay supplies battery voltage to six valve solenoids (RF dump/isolation, LF dump/isolation, and rear dump/isolation). Common causes include Faulty Electronic Brake Control Module (EBCM), Electronic Brake Control Module (EBCM) harness is open or shorted, Electronic Brake Control Module (EBCM) 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: C0266 Cadillac indicates EBCM Motor Relay Circuit High When Off.
Common causes: Common causes include Faulty Electronic Brake Control Module (EBCM), Electronic Brake Control Module (EBCM) harness is open or shorted, Electronic Brake Control Module (EBCM) 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 1,241

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 C0266 Cadillac Description

The ABS relay supplies battery voltage to six valve solenoids (RF dump/isolation, LF dump/isolation, and rear dump/isolation). The Electronic Brake Control Module (EBCM) microprocessor applies the grounds needed to activate each solenoid. The low side of each solenoid coil has a feedback circuit to the EBCM microprocessor. When a solenoid is commanded OFF, the feedback voltage is high. When a solenoid is commanded ON, the feedback voltage is low.

OBDII Code C0266 Cadillac - EBCM Motor Relay Circuit High When Off - AutoCodes.com — C0266 Cadillac Code - EBCM Motor Relay Circuit High When Off

What does this mean?

What are the Possible Causes of the DTC C0266 Cadillac?

Faulty Electronic Brake Control Module (EBCM)
Electronic Brake Control Module (EBCM) harness is open or shorted
Electronic Brake Control Module (EBCM) circuit poor electrical connection

How to Fix the DTC C0266 Cadillac?

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 C0266 Cadillac 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.

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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 C0266 Cadillac Code

1. What are the common symptoms of OBDII code C0266 in a Cadillac related to the EBCM Motor Relay Circuit High When Off?

- Common symptoms include the ABS warning light illuminated on the dashboard, potential loss of ABS functionality, and possible traction control issues.

2. What can cause the EBCM Motor Relay Circuit High When Off error code C0266 in a Cadillac?

- Possible causes include a faulty electronic brake control module (EBCM), damaged wiring or connectors, or a malfunctioning EBCM motor relay.

3. How can I diagnose the EBCM Motor Relay Circuit High When Off issue in my Cadillac?

- Diagnosis typically involves using an OBDII scanner to retrieve the specific trouble code, inspecting the EBCM and related components for any visible damage, and performing electrical tests to pinpoint the source of the problem.

4. Can I continue driving my Cadillac with the C0266 code related to the EBCM Motor Relay Circuit High When Off?

- It is not recommended to continue driving the vehicle with this code present, as it may affect the ABS system's performance, potentially compromising safety.

5. How can I repair the EBCM Motor Relay Circuit High When Off problem in my Cadillac?

- Repair options may include replacing the faulty EBCM, repairing damaged wiring or connectors, or replacing the malfunctioning EBCM motor relay.

6. Is it possible to reset the OBDII code C0266 in a Cadillac without fixing the underlying issue?

- While clearing the trouble code may temporarily turn off the warning light, the issue will likely recur if the root cause is not addressed.

7. Will the EBCM Motor Relay Circuit High When Off code affect my Cadillac's overall drivability?

- In most cases, the code may not significantly impact the vehicle's drivability, but it can compromise the ABS system's functionality and overall safety.

8. How much does it typically cost to repair the EBCM Motor Relay Circuit High When Off issue in a Cadillac?

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

9. Are there any preventive maintenance measures to avoid encountering the C0266 code in a Cadillac?

- Regularly inspecting the ABS system components, addressing any warning lights promptly, and maintaining the vehicle's electrical system can help prevent issues leading to this trouble code.

10. Can a DIY enthusiast with moderate automotive repair skills fix the EBCM Motor Relay Circuit High When Off problem in a Cadillac?

- While some DIY enthusiasts may be able to diagnose and address simple causes like damaged wiring, resolving more complex issues related to the EBCM or its components may require professional expertise.