AutoCodes – Generic – B1778

B1778 Code - Mirror Driver Down Circuit Failure

Quick Answer

The Body Control Module (BCM) monitors the Mirror Driver Down Motor. Common causes include Faulty Mirror Driver Down Motor, Mirror Driver Down Motor harness is open or shorted, Mirror Driver Down Motor 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: B1778 indicates Mirror Driver Down Circuit Failure.
Common causes: Common causes include Faulty Mirror Driver Down Motor, Mirror Driver Down Motor harness is open or shorted, Mirror Driver Down Motor 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 4,653

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 Jun 26, 2019

Description
Possible Causes
How To Fix
Cost to Diagnose
FAQs
Comments
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Code B1778 Description

The Body Control Module (BCM) monitors the Mirror Driver Down Motor. The BCM sets the OBDII code when the Mirror Driver Down Motor is not to factory specifications.

OBDII Code B1778 - Mirror Driver Down Circuit Failure - AutoCodes.com — B1778 Code - Mirror Driver Down Circuit Failure

What does this mean?

What are the Possible Causes of the DTC B1778?

Faulty Mirror Driver Down Motor
Mirror Driver Down Motor harness is open or shorted
Mirror Driver Down Motor circuit poor electrical connection
Faulty Body Control Module (BCM)

How to Fix the DTC B1778?

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 B1778 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 B1778 code?

Need more information on how to fix the B1778 code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B1778 code diagnosed by a professional: Find a repair shop in your area

Information for Specific Makes

B1778 Nissan — Trunk Open Output Signal

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 B1778 Code

1. What are common symptoms of OBDII code B1778 Mirror Driver Down Circuit Failure?

- Common symptoms include the driver-side mirror not adjusting properly or moving incorrectly when the adjustment controls are used.

2. What are possible causes of OBDII code B1778 Mirror Driver Down Circuit Failure?

- Possible causes include a faulty mirror motor, damaged mirror wiring, a defective mirror control switch, or a problem with the mirror control module.

3. How can I diagnose the issue related to OBDII code B1778 Mirror Driver Down Circuit Failure?

- You can use a multimeter to test the mirror motor, check the wiring for any visible damage, inspect the mirror control switch for functionality, and perform a scan tool diagnosis to pinpoint the issue.

4. Can a DIY enthusiast repair OBDII code B1778 Mirror Driver Down Circuit Failure?

- Depending on their skills and experience, a DIY enthusiast may be able to repair this issue by replacing the faulty mirror motor, repairing damaged wiring, or fixing the mirror control switch.

5. Is it safe to continue driving with OBDII code B1778 Mirror Driver Down Circuit Failure?

- It is generally safe to continue driving, but it is recommended to address the issue promptly to ensure proper functionality of the driver-side mirror for visibility and safety.

6. Are there any simple troubleshooting steps I can take for OBDII code B1778 Mirror Driver Down Circuit Failure?

- You can start by checking the mirror adjustment controls, ensuring they are functioning correctly, and inspecting the mirror wiring for any obvious damage before proceeding with further diagnosis.

7. How much does it typically cost to repair OBDII code B1778 Mirror Driver Down Circuit Failure at a repair shop?

- Repair costs can vary depending on the specific cause of the issue, but it may range from $100 to $300 for parts and labor at a repair shop.

8. Can extreme weather conditions affect OBDII code B1778 Mirror Driver Down Circuit Failure?

- Extreme weather conditions, such as intense heat or cold, can potentially exacerbate issues related to the mirror motor or wiring, leading to the Mirror Driver Down Circuit Failure code.

9. Will resetting the OBDII system clear the B1778 Mirror Driver Down Circuit Failure code?

- Resetting the OBDII system may temporarily clear the code, but it is important to address the underlying issue causing the Mirror Driver Down Circuit Failure to prevent the code from reoccurring.

10. Are there any recalls or technical service bulletins related to OBDII code B1778 Mirror Driver Down Circuit Failure?

- It is recommended to check with the vehicle manufacturer or authorized dealerships for any recalls or technical service bulletins related to the B1778 Mirror Driver Down Circuit Failure code to see if there are known issues or remedies available.