AutoCodes – Mitsubishi – C121D Mitsubishi

C121D Mitsubishi Code - Brake Fluid Pressure Sensor Circuit

Quick Answer

The Anti-Lock Brake System (ABS) Module monitors the Brake Pressure Sensor. Common causes include Faulty Brake Master Cylinder, Faulty Brake Booster, Faulty Anti-Lock Brake System (ABS) Module. 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: C121D Mitsubishi indicates Brake Fluid Pressure Sensor Circuit.
Common causes: Common causes include Faulty Brake Master Cylinder, Faulty Brake Booster, Faulty Anti-Lock Brake System (ABS) Module.
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 9,162

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 Aug 25, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code C121D Mitsubishi Description

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

OBDII Code C121D Mitsubishi - Brake Fluid Pressure Sensor Circuit - AutoCodes.com — C121D Mitsubishi Code - Brake Fluid Pressure Sensor Circuit

What does this mean?

What are the Possible Causes of the DTC C121D Mitsubishi?

Faulty Brake Master Cylinder
Faulty Brake Booster
Faulty Anti-Lock Brake System (ABS) Module
Anti-Lock Brake System (ABS) Module harness is open or shorted
Anti-Lock Brake System (ABS) Module circuit poor electrical connection

How to Fix the DTC C121D Mitsubishi?

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 C121D Mitsubishi 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 C121D Mitsubishi 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 C121D Mitsubishi Code

1. What are the common symptoms of OBDII code C121D in a Mitsubishi related to the Brake Fluid Pressure Sensor Circuit?

The common symptoms include the ABS warning light being illuminated on the dashboard, potential loss of ABS functionality, and possible issues with brake system performance.

2. What are the possible causes of OBDII code C121D in a Mitsubishi?

Common causes of this code include a faulty brake fluid pressure sensor, damaged wiring or connectors in the sensor circuit, low brake fluid levels, or issues with the ABS module.

3. How can I diagnose the cause of OBDII code C121D in my Mitsubishi?

Diagnosing this code typically involves using a diagnostic scanner to read the code, checking the brake fluid level, inspecting the brake fluid pressure sensor and its wiring, and testing the ABS module for any faults.

4. Can I still drive my Mitsubishi with OBDII code C121D present?

It is not recommended to drive your vehicle with this code present, as it may indicate potential issues with the brake system that could compromise safety. It is advisable to have the issue diagnosed and repaired as soon as possible.

5. How can I repair OBDII code C121D in my Mitsubishi related to the Brake Fluid Pressure Sensor Circuit?

Repairing this code may involve replacing the brake fluid pressure sensor, repairing or replacing damaged wiring or connectors, topping up the brake fluid levels, or addressing any faults in the ABS module.

6. Is it possible to reset the OBDII code C121D in my Mitsubishi without fixing the issue?

While you can clear the code using a diagnostic scanner, it is not recommended to do so without addressing the underlying problem. The code is likely to return if the root cause is not fixed.

7. How much does it typically cost to repair OBDII code C121D in a Mitsubishi?

The cost of repairing this code can vary depending on the specific cause of the issue, the parts needed for the repair, and labor costs. It is advisable to consult a mechanic for an accurate estimate.

8. Can a DIY enthusiast repair OBDII code C121D in a Mitsubishi, or is it best left to professionals?

While some DIY enthusiasts may be able to diagnose and repair this code, it is a complex issue related to the brake system and ABS module. For safety reasons, it is often best to have a professional mechanic handle the repair.

9. Are there any preventive maintenance tips to avoid OBDII code C121D in a Mitsubishi?

Regularly checking and maintaining the brake fluid levels, inspecting the brake system for any leaks or damage, and addressing any warning lights on the dashboard promptly can help prevent issues that may trigger this code.

10. How long does it typically take to repair OBDII code C121D in a Mitsubishi?

The repair time can vary depending on the specific cause of the issue, the availability of parts, and the mechanic's experience. In general, it may take a few hours to a full day to diagnose and repair this code.