AutoCodes – Generic – C1402

C1402 Code - Front Speed Sensor Left Malfunction

Quick Answer

The speed sensor detects the wheel speed and sends the appropriate signals to the Skid Control ECU (Brake Actuator Assembly). Common causes include Faulty Front Speed Sensor Left, Front Speed Sensor Left Rotor (Front Axle Hub Sub-Assembly Left), Front Speed Sensor Left harness is open or shorted. 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: C1402 indicates Front Speed Sensor Left Malfunction.
Common causes: Common causes include Faulty Front Speed Sensor Left, Front Speed Sensor Left Rotor (Front Axle Hub Sub-Assembly Left), Front Speed Sensor Left harness is open or shorted.
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 21,029

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 Jan 19, 2023

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code C1402 Description

The speed sensor detects the wheel speed and sends the appropriate signals to the Skid Control ECU (Brake Actuator Assembly). These signals are used for Anti-Lock Brake System (ABS) control. Speed sensor rotors have rows of alternating N and S magnetic poles, and their magnetic fields change when the rotors turn. Each speed sensor detects that magnetic change and sends a pulse signal to the Skid Control ECU (Brake Actuator Assembly).

OBDII Code C1402 - Front Speed Sensor Left Malfunction - AutoCodes.com — C1402 Code - Front Speed Sensor Left Malfunction

What does this mean?

What are the Possible Causes of the DTC C1402?

Faulty Front Speed Sensor Left
Front Speed Sensor Left Rotor (Front Axle Hub Sub-Assembly Left)
Front Speed Sensor Left harness is open or shorted
Front Speed Sensor Left circuit poor electrical connection

How to Fix the DTC C1402?

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 no damage to the speed sensor tip is found during this inspection, do not replace the speed sensor.
If there is iron powder sticking to the rotor, this will result in a malfunction, so confirm that the rotor is not contaminated with foreign material before replacing the sensor.
Check the speed sensor signal after cleaning or replacement.
On most vehicles, the Front Speed Sensor Rotor is incorporated into the Front Axle Hub Sub-Assembly. If the Speed Sensor Rotor needs to be replaced, replace it together with the Front Axle Hub Sub-Assembly.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the C1402 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 C1402 code?

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Need Help with the Code?

Get the C1402 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

C1402 Chrysler — Transfer Case Range Select Switch Circuit High
C1402 Dodge — Transfer Case Range Select Switch Circuit High
C1402 Jeep — Transfer Case Range Select Switch Circuit High
C1402 Lexus — Front Speed Sensor Left Malfunction
C1402 Scion — Front Speed Sensor Left Malfunction
C1402 Toyota — Front Speed Sensor Left Malfunction

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 C1402 Code

1. What does OBDII code C1402 mean?

C1402 indicates a malfunction in the front left wheel speed sensor, which is part of the anti-lock braking system (ABS).

2. What are the symptoms of C1402?

Common symptoms include an illuminated ABS warning light, reduced braking performance, and possible loss of ABS functionality.

3. What causes the C1402 code?

The code is typically caused by a faulty front left wheel speed sensor, damaged wiring, corroded connectors, or debris affecting the sensor.

4. Can I drive with the C1402 code?

While the vehicle may still be drivable, the ABS system may not function properly, increasing the risk of skidding during hard braking or on slippery surfaces.

5. How do I diagnose the C1402 code?

Inspect the front left wheel speed sensor for damage, check the wiring and connectors for corrosion or wear, and test the sensorâ€™s signal using a multimeter.

6. How do you fix the C1402 code?

Repairs may involve replacing the front left wheel speed sensor, repairing or replacing damaged wiring, or cleaning debris from the sensor area.

7. How much does it cost to fix the C1402 code?

Repair costs can range from $100 to $300, depending on whether the sensor needs replacement and the labor rates in your area.

8. Can a dirty wheel speed sensor trigger the C1402 code?

Yes, dirt, debris, or rust around the front left wheel speed sensor can interfere with its function and cause the code.

9. Does the C1402 code affect other systems?

Yes, since the ABS is linked to traction control and stability control, those systems may also be disabled or impaired.

10. How can I prevent the C1402 code from reoccurring?

Regularly inspect and clean the wheel speed sensors, ensure wiring is secured and undamaged, and avoid driving in areas with excessive debris buildup.