AutoCodes – Generic – C1120

C1120 Code - Front Left Input ABS Solenoid

Quick Answer

The control unit computes the wheel rotating speed by the signal sent from the sensor. Common causes include Faulty ABS Actuator/Electric Unit, ABS Actuator/Electric Unit harness is open or shorted, ABS Actuator/Electric Unit 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: C1120 indicates Front Left Input ABS Solenoid.
Common causes: Common causes include Faulty ABS Actuator/Electric Unit, ABS Actuator/Electric Unit harness is open or shorted, ABS Actuator/Electric Unit 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 15,341

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 16, 2020

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code C1120 Description

The control unit computes the wheel rotating speed by the signal sent from the sensor. Then it supplies a DC current to the actuator solenoid valve. It also controls ON-OFF operation of the solenoid valve relay and motor relay. If any electrical malfunction should be detected in the system, the control unit causes the warning lamp to turn on. In this condition, the ABS will be deactivated by the control unit, and the vehicle's brake system reverts to normal operation.
The ABS actuator and electric unit (control unit) contains: An electric motor and pump, Two relays, Eight solenoid valves ( each inlet and outlet for LH front, RH front, LH rear, RH rear), and ABS control unit.
These components control the hydraulic circuit that increases, holds or decreases hydraulic pressure to all or individual wheels. The ABS actuator and electric unit (control unit) cannot be disassembled and must be replaced as an assembly.

OBDII Code C1120 - Front Left Input ABS Solenoid - AutoCodes.com — C1120 Code - Front Left Input ABS Solenoid

What does this mean?

What are the Possible Causes of the DTC C1120?

Faulty ABS Actuator/Electric Unit
ABS Actuator/Electric Unit harness is open or shorted
ABS Actuator/Electric Unit poor electrical connection

How to Fix the DTC C1120?

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

The ABS has an electronic control unit to control major functions. The control unit accepts input signals from sensors and controls operation of the actuator. It is also important to check for conventional problems such as air leaks in the booster or lines, lack of brake fluid, or other problems with the brake system.
It is much more difficult to diagnose a problem that occurs intermittently rather than continuously. Most intermittent problems are caused by poor electrical connections or faulty wiring. In this case, careful checking of suspicious circuits may help prevent the replacement of good parts.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the C1120 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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Need Help with the Code?

Get the C1120 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

C1120 Infiniti — Front Left Input ABS Solenoid
C1120 Nissan — Front Left Input ABS Solenoid

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 C1120 Code

1. What are common symptoms of OBDII code C1120 (Front Left Input ABS Solenoid)?

Common symptoms include the ABS warning light illuminating on the dashboard, decreased braking performance, and potential ABS system malfunctions.

2. What can cause OBDII code C1120 to trigger?

The code C1120 is typically triggered by a malfunction in the front left ABS solenoid, which may be caused by wiring issues, a faulty solenoid, or problems with the ABS control module.

3. How can I diagnose the cause of OBDII code C1120?

Diagnosing code C1120 involves using a diagnostic scanner to read the code, inspecting the front left ABS solenoid and its wiring for any visible damage, and testing the solenoid and related components for proper functionality.

4. What are some repair tips for fixing OBDII code C1120?

Repair tips include checking and repairing any damaged wiring, replacing the front left ABS solenoid if faulty, ensuring proper connections, and resetting the ABS system after repairs are made.

5. Can driving with OBDII code C1120 pose any risks?

Driving with OBDII code C1120 can pose risks, such as reduced braking efficiency and potential loss of ABS functionality, which can affect the vehicle's ability to maintain traction and stability during braking.

6. How important is it to address OBDII code C1120 promptly?

It is important to address OBDII code C1120 promptly to ensure the ABS system functions properly, maintain safe braking performance, and prevent potential safety hazards on the road.

7. Is it possible to clear OBDII code C1120 without fixing the issue?

Clearing the code without fixing the underlying issue may temporarily turn off the warning light, but the problem will persist, leading to ongoing ABS system malfunctions and potential safety risks.

8. Can OBDII code C1120 be intermittent?

Yes, OBDII code C1120 can be intermittent, with the ABS warning light appearing and disappearing sporadically as the issue with the front left ABS solenoid comes and goes.

9. How much does it typically cost to repair OBDII code C1120?

The cost to repair OBDII code C1120 can vary depending on the cause of the issue, the extent of the repairs needed, and labor rates. It is recommended to consult a professional mechanic for an accurate estimate.

10. Can OBDII code C1120 be prevented?

While some causes of OBDII code C1120 may be unavoidable, regular maintenance, prompt repairs of ABS system issues, and careful driving can help prevent the recurrence of this code.