AutoCodes – GMC – B127B 2014 GMC Sierra

B127B 2014 GMC Sierra Code - Rearview Camera Input Signal Circuit

Quick Answer

When the transmission is placed into R, a 12 V signal is sent to the Rearview Camera indicating that camera operation is requested. Common causes include Faulty Rearview Camera, Rearview Camera harness is open or shorted, Rearview Camera circuit poor electrical connection. Severity is Moderate - service should be scheduled soon. The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

What it means: B127B 2014 GMC Sierra indicates Rearview Camera Input Signal Circuit.
Common causes: Common causes include Faulty Rearview Camera, Rearview Camera harness is open or shorted, Rearview Camera circuit poor electrical connection.
Severity: Moderate - service should be scheduled soon.
Can I drive?: The vehicle may still be drivable for short trips if it runs normally, but avoid hard driving and repair it soon.

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Code Popularity 360

How popular is this code, among other codes? Low

Repair Importance Level

Moderate (Service soon) (2 / 3)

Repair Difficulty Level

Intermediate (2 / 3)

What is this?

Table of contents Created and updated by William Orellana on Nov 29, 2024

Description
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
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Code B127B 2014 GMC Sierra Description

When the transmission is placed into R, a 12 V signal is sent to the Rearview Camera indicating that camera operation is requested. Ignition voltage and ground are supplied to the Rearview Camera. The Rearview Camera sends a video image to the Human Machine Interface Control Module Bypass Module through a video signal + and a video signal − circuit. The Human Machine Interface Control Module Bypass Module passes the video image to Human Machine Interface Control Module via video signal + and a video signal − circuits. The Human Machine Interface Control Module Bypass Module is used to ensure the Human Machine Interface Control Module produces a quality rear vision camera image to be displayed on the Info Display Module when the vehicle is placed in reverse gear. In the event, the Human Machine Interface Control Module Bypass Module detects an issue with the camera image generated by the Human Machine Interface Control Module, such as black, solid color, frozen, or image other than the camera image, the Human Machine Interface Control Module Bypass Module will assume control of the image to the Info Display Module and displays a raw camera image with no park assist projection lines or object detection symbols for the entire reverse cycle.
The Human Machine Interface Control Module Bypass Module is part of the video signal + and a video signal − circuits path from the Rearview Camera to the Human Machine Interface Control Module as well as the digital Low Voltage Differential Signaling (LVDS) path (USB cable) between the Human Machine Interface Control Module and Info Display Module and needs to be active for either signal to be received by these modules. The Human Machine Interface Control Module Bypass Module is not connected to serial data and uses the reverse lamp voltage input to determine the vehicle gear state.
The Diagnostic Trouble Code (DTC) will be set when the video signal from the rearview camera has not been received by the Radio for 2.5 s.

OBDII Code B127B 2014 GMC Sierra - Rearview Camera Input Signal Circuit - AutoCodes.com — B127B 2014 GMC Sierra Code - Rearview Camera Input Signal Circuit

What does this mean?

What are the Possible Causes of the DTC B127B 2014 GMC Sierra?

Faulty Rearview Camera
Rearview Camera harness is open or shorted
Rearview Camera circuit poor electrical connection
Faulty Human Machine Interface Control Module
Faulty Info Display Module

How to Fix the DTC B127B 2014 GMC Sierra?

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

A poor video image can be caused by ice, snow, and mud buildup on the lens of the Rearview Camera. Also, extreme lighting conditions can affect performance, such as operating in the dark or with bright sunlight shining on the camera. Extreme high or low temperatures can also affect image quality. An open or high resistance in the shield of the video signal circuit can also cause a distorted screen.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the B127B 2014 GMC Sierra 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 B127B 2014 GMC Sierra Code

1. What are the common symptoms of OBDII code B127B in a 2014 GMC Sierra related to the Rearview Camera Input Signal Circuit?

- Common symptoms include a malfunctioning rearview camera display, distorted or flickering images, or a complete loss of the rearview camera function.

2. What are the possible causes of OBDII code B127B in a 2014 GMC Sierra?

- The code B127B can be triggered by issues such as damaged wiring or connectors in the rearview camera system, a faulty rearview camera module, or a defective camera itself.

3. How can I diagnose the Rearview Camera Input Signal Circuit issue causing OBDII code B127B in my 2014 GMC Sierra?

- To diagnose the problem, you can start by checking the wiring and connectors for any visible damage, testing the rearview camera module, and ensuring the camera is securely mounted and functioning properly.

4. Is it safe to continue driving my 2014 GMC Sierra with OBDII code B127B related to the Rearview Camera Input Signal Circuit?

- While it may be safe to drive without the rearview camera function, it is recommended to address the issue promptly to ensure optimal vehicle safety and convenience.

5. Can I repair OBDII code B127B in my 2014 GMC Sierra related to the Rearview Camera Input Signal Circuit myself?

- Depending on your level of automotive expertise, you may be able to address the issue by checking and repairing wiring, connectors, or the camera module. However, professional diagnosis and repair may be necessary for more complex issues.

6. Are there any simple troubleshooting steps I can take before seeking professional help for OBDII code B127B in my 2014 GMC Sierra?

- You can start by checking the fuse related to the rearview camera system, ensuring the camera lens is clean and unobstructed, and resetting the vehicle's electronic system by disconnecting the battery for a few minutes.

7. How much does it typically cost to repair OBDII code B127B in a 2014 GMC Sierra related to the Rearview Camera Input Signal Circuit?

- The cost of repair can vary depending on the exact cause of the issue, but it may involve expenses for parts replacement, labor, and diagnostic fees. It is advisable to obtain quotes from reputable auto repair shops.

8. Will fixing OBDII code B127B in my 2014 GMC Sierra require reprogramming or calibration of the rearview camera system?

- Depending on the repair performed, reprogramming or recalibration of the rearview camera system may be necessary to ensure proper functionality and alignment with the vehicle's electronics.

9. Can extreme weather conditions or environmental factors contribute to triggering OBDII code B127B in a 2014 GMC Sierra?

- Yes, exposure to extreme temperatures, moisture, or physical damage from debris can potentially affect the rearview camera system and lead to the triggering of code B127B.

10. How can I prevent OBDII code B127B related to the Rearview Camera Input Signal Circuit from occurring again in my 2014 GMC Sierra?

- To prevent future occurrences, regularly inspect and maintain the rearview camera system, protect it from environmental elements, and address any issues promptly to avoid further damage.