AutoCodes – GMC – B127B 2017 GMC Sierra

B127B 2017 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 2017 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 269

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 2017 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 2017 GMC Sierra - Rearview Camera Input Signal Circuit - AutoCodes.com — B127B 2017 GMC Sierra Code - Rearview Camera Input Signal Circuit

What does this mean?

What are the Possible Causes of the DTC B127B 2017 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 2017 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 2017 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 2017 GMC Sierra code?

Need more information on how to fix the B127B 2017 GMC Sierra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the B127B 2017 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 2017 GMC Sierra Code

1. What are the common symptoms of OBDII code B127B in a 2017 GMC Sierra related to the Rearview Camera Input Signal Circuit?

The common symptoms include a malfunctioning or non-functional rearview camera display on the vehicle's screen.

2. What are the possible causes of OBDII code B127B in a 2017 GMC Sierra?

Possible causes of this code include a faulty rearview camera, damaged wiring or connectors in the camera circuit, or a malfunctioning camera control module.

3. How can I diagnose the issue causing OBDII code B127B in my 2017 GMC Sierra?

Diagnosing the issue involves checking the rearview camera for physical damage, inspecting the wiring and connectors for any signs of wear or corrosion, and using a diagnostic tool to test the camera control module.

4. Can I repair OBDII code B127B in my 2017 GMC Sierra myself?

Depending on your expertise and tools available, you may be able to repair this issue yourself by replacing a faulty rearview camera, repairing damaged wiring, or addressing any issues with the camera control module.

5. Is it safe to drive my 2017 GMC Sierra with OBDII code B127B related to the Rearview Camera Input Signal Circuit?

It is generally safe to drive the vehicle with this code, but you may lose the functionality of the rearview camera until the issue is resolved.

6. How much does it typically cost to repair OBDII code B127B in a 2017 GMC Sierra at a dealership or repair shop?

The cost of repair can vary depending on the specific issue causing the code, but it may involve part replacement, labor costs, and diagnostic fees.

7. Are there any temporary fixes or workarounds for OBDII code B127B in a 2017 GMC Sierra?

Temporary fixes may include checking and securing any loose connections in the camera circuit or resetting the vehicle's electronics by disconnecting the battery for a few minutes.

8. Will resetting the OBDII code B127B in my 2017 GMC Sierra make it go away permanently?

Resetting the code may temporarily clear it, but if the underlying issue causing the code is not addressed, it is likely to reappear once the problem is detected again.

9. Can extreme weather conditions affect the Rearview Camera Input Signal Circuit in a 2017 GMC Sierra and trigger OBDII code B127B?

Extreme weather conditions such as heat, cold, or moisture can potentially affect the rearview camera circuit, leading to issues that trigger this OBDII code.

10. Is it necessary to have the rearview camera recalibrated after repairing OBDII code B127B in a 2017 GMC Sierra?

In some cases, recalibrating the rearview camera system may be necessary after repairing the issue to ensure proper functionality and alignment of the camera display.