AutoCodes – GMC – B127B 2015 GMC Sierra

B127B 2015 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 2015 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.

Save to My Repairs My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 390

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
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code B127B 2015 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 2015 GMC Sierra - Rearview Camera Input Signal Circuit - AutoCodes.com — B127B 2015 GMC Sierra Code - Rearview Camera Input Signal Circuit

What does this mean?

What are the Possible Causes of the DTC B127B 2015 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 2015 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 2015 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.

Need more information about the B127B 2015 GMC Sierra code?

Need more information on how to fix the B127B 2015 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B127B 2015 GMC Sierra code diagnosed by a professional: Find a repair shop in your area

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 2015 GMC Sierra Code

1. What are the common symptoms of OBDII code B127B in a 2015 GMC Sierra related to the Rearview Camera Input Signal Circuit?

- Common symptoms include a malfunctioning rearview camera, a blank or distorted display on the screen, and intermittent issues with the camera feed.

2. What are the possible causes of OBDII code B127B in a 2015 GMC Sierra?

- Possible causes may include a faulty rearview camera, damaged wiring or connectors in the camera circuit, or issues with the camera control module.

3. How can I diagnose the Rearview Camera Input Signal Circuit issue in my 2015 GMC Sierra?

- You can start by inspecting the rearview camera for any visible damage, checking the wiring and connectors for connectivity issues, and using a diagnostic tool to retrieve specific error codes.

4. Can I repair OBDII code B127B in my 2015 GMC Sierra at home?

- Depending on the root cause, some repairs like replacing a faulty rearview camera or repairing a damaged wire may be possible at home for those with automotive repair experience and the right tools.

5. Is it safe to continue driving my 2015 GMC Sierra with the Rearview Camera Input Signal Circuit problem?

- While it may be safe to drive, it is recommended to address the issue promptly to ensure proper functionality of the rearview camera system, which can aid in safe reversing and parking.

6. How much can I expect to pay for repairing OBDII code B127B in a 2015 GMC Sierra at a repair shop?

- Repair costs can vary depending on the exact cause of the issue, but you can expect to pay for diagnostic time, replacement parts, and labor, which may range from a few hundred to over a thousand dollars.

7. Are there any temporary fixes or workarounds for OBDII code B127B in a 2015 GMC Sierra?

- While temporary fixes like tapping on the camera or checking for loose connections may work in some cases, it is advisable to address the root cause of the issue for a permanent solution.

8. Can extreme weather conditions affect the Rearview Camera Input Signal Circuit in a 2015 GMC Sierra?

- Yes, extreme temperatures or moisture can potentially damage the rearview camera, wiring, or connectors, leading to issues with the camera input signal circuit.

9. Will resetting the OBDII system clear the B127B code in my 2015 GMC Sierra?

- Resetting the system may temporarily clear the code, but if the underlying issue is not addressed, the code is likely to reappear upon subsequent use of the rearview camera.

10. How can I prevent OBDII code B127B from occurring in my 2015 GMC Sierra in the future?

- Regularly inspecting and maintaining the rearview camera system, avoiding physical damage to the camera and wiring, and addressing any issues promptly can help prevent the recurrence of this code.