AutoCodes – Subaru – C0021 Subaru

C0021 Subaru Code - Front Right ABS Sensor Circuit Open Or Short

Quick Answer

The Anti-Lock Brake System (ABS) Module monitors the Front Right ABS Sensor. Common causes include Faulty Front Right ABS Sensor, Front Right ABS Sensor harness is open or shorted, Front Right ABS Sensor 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: C0021 Subaru indicates Front Right ABS Sensor Circuit Open Or Short.
Common causes: Common causes include Faulty Front Right ABS Sensor, Front Right ABS Sensor harness is open or shorted, Front Right ABS Sensor 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 8,682

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 01, 2020

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code C0021 Subaru Description

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

OBDII Code C0021 Subaru - Front Right ABS Sensor Circuit Open Or Short - AutoCodes.com — C0021 Subaru Code - Front Right ABS Sensor Circuit Open Or Short

What does this mean?

What are the Possible Causes of the DTC C0021 Subaru?

Faulty Front Right ABS Sensor
Front Right ABS Sensor harness is open or shorted
Front Right ABS Sensor circuit poor electrical connection

How to Fix the DTC C0021 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 C0021 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.

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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 C0021 Subaru Code

1. What does the OBDII code C0021 indicate on a Subaru?

The code C0021 on a Subaru indicates an issue with the Front Right ABS Sensor Circuit, specifically a potential open or short in the circuit.

2. What are common symptoms of code C0021 in a Subaru?

Common symptoms include the ABS warning light being illuminated on the dashboard, reduced effectiveness of the anti-lock braking system, and in some cases, the vehicleâ€™s braking system may revert to non-ABS mode.

3. What can cause the OBDII code C0021 to appear on a Subaru?

Causes of the C0021 code can include damaged wiring or connectors in the front right ABS sensor circuit, a faulty front right ABS sensor, or issues with the ABS module itself.

4. How can I troubleshoot the C0021 code in a Subaru?

Start by visually inspecting the front right ABS sensor and its wiring for any signs of damage or disconnection. Check for corrosion on the connectors and ensure that the wiring is not frayed, broken, or shorted out.

5. What steps should be taken to repair a Subaru showing the C0021 code?

Repairing this code may involve replacing the front right ABS sensor, repairing or replacing damaged wires or connectors in the sensor circuit, or in more complex cases, servicing or replacing the ABS module.

6. Is it safe to drive a Subaru with the C0021 code?

While the vehicle can still be driven, driving with the C0021 code can be risky as the ABS function may be impaired. It's advisable to address the issue promptly to maintain optimal braking performance, especially under slippery or abrupt stopping conditions.

7. How much does it typically cost to fix the C0021 code in a Subaru?

The cost can vary widely based on the exact issue and the vehicle's condition. Replacing an ABS sensor can cost anywhere from $200 to $400 including parts and labor. If the issue is related to the ABS module, costs could be significantly higher.

8. Can a faulty front right ABS sensor affect the overall handling of a Subaru?

Yes, a faulty sensor can affect the handling, particularly in situations requiring ABS intervention (like emergency braking or slippery conditions), as the system may not regulate brake pressure optimally across the wheels.

9. What tools are needed to diagnose the C0021 code on a Subaru?

A professional quality OBDII scanner, a digital multimeter, and possibly an oscilloscope to diagnose issues with the sensor or wiring accurately.

10. How often do front right ABS sensor issues occur in Subarus?

Issues with ABS sensors can occur but arenâ€™t necessarily common in all Subaru models. Environmental factors, driving conditions, and maintenance history can all influence the frequency of such issues.