AutoCodes – Generic – C1380

C1380 Code - Stop Light Control Relay Malfunction

Quick Answer

Upon receiving the trailer sway control operating signal from the Skid Control ECU (Brake Actuator Assembly), the relay contact turns on and the stop lights come on. Common causes include Faulty Stop Light fuse, Stop Light harness is open or shorted, Stop Light 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: C1380 indicates Stop Light Control Relay Malfunction.
Common causes: Common causes include Faulty Stop Light fuse, Stop Light harness is open or shorted, Stop Light 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 3,514

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 23, 2023

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code C1380 Description

Upon receiving the trailer sway control operating signal from the Skid Control ECU (Brake Actuator Assembly), the relay contact turns on and the stop lights come on. The Skid Control ECU (Brake Actuator Assembly) sets the OBDII code when the Stop light is not to factory specifications.

OBDII Code C1380 - Stop Light Control Relay Malfunction - AutoCodes.com — C1380 Code - Stop Light Control Relay Malfunction

What does this mean?

What are the Possible Causes of the DTC C1380?

Faulty Stop Light fuse
Stop Light harness is open or shorted
Stop Light circuit poor electrical connection
Faulty Stop Light Control Relay (Bulb type Stop Light)
Faulty Stop Light Control ECU Assembly (LED type Stop Light)
Faulty Skid Control ECU (Brake Actuator Assembly)

How to Fix the DTC C1380?

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 C1380 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 C1380 code?

Need more information on how to fix the C1380 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the C1380 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

C1380 Lexus — Stop Light Control Relay Malfunction
C1380 Scion — Stop Light Control Relay Malfunction
C1380 Toyota — Stop Light Control Relay 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 C1380 Code

1. What are the common symptoms of OBDII code C1380 (Stop Light Control Relay Malfunction)?

Common symptoms include non-functioning brake lights, illuminated brake warning light on the dashboard, and potential issues with the vehicle's cruise control system.

2. What are the possible causes of OBDII code C1380?

Possible causes of this code include a faulty stop light control relay, damaged wiring or connectors in the brake light circuit, or a malfunctioning brake light switch.

3. How can I diagnose the cause of OBDII code C1380?

To diagnose this code, you can start by checking the stop light control relay, inspecting the brake light circuit for any visible damage, and testing the brake light switch for proper functionality using a multimeter.

4. Can a malfunctioning stop light control relay affect vehicle safety?

Yes, a malfunctioning stop light control relay can affect vehicle safety by causing the brake lights to not illuminate properly, potentially leading to rear-end collisions due to other drivers not being able to see when you are braking.

5. Is it safe to drive with OBDII code C1380 present?

It is not recommended to drive with OBDII code C1380 present, as non-functioning brake lights can compromise your safety on the road. It is best to address the issue promptly.

6. How can I repair OBDII code C1380?

Repairing this code typically involves replacing the faulty stop light control relay, repairing any damaged wiring or connectors, and ensuring the brake light switch is functioning correctly.

7. Are there any DIY tips for fixing OBDII code C1380?

While some basic troubleshooting can be done at home, it is recommended to have a professional mechanic diagnose and repair OBDII code C1380 to ensure the issue is properly resolved.

8. Can a malfunctioning stop light control relay cause other OBDII codes to appear?

Yes, a malfunctioning stop light control relay can potentially trigger other related OBDII codes, such as codes related to the brake light circuit or cruise control system.

9. How much does it cost to repair OBDII code C1380?

The cost of repairing OBDII code C1380 can vary depending on the underlying cause of the issue, the cost of parts, and labor rates. It is advisable to get an estimate from a trusted mechanic.

10. Will resetting the OBDII system clear code C1380?

Resetting the OBDII system may temporarily clear the code, but if the underlying issue is not addressed, the code is likely to reappear. It is essential to diagnose and repair the root cause of the problem.