B127B on Chevrolet: How to Diagnose & Fix
Rearview Camera Input Signal Circuit
1 Chevrolet model · 1 documented issue · 1 critical
B127B on Chevrolet by model: symptoms, diagnosis and fix
Multiple owners have reported the rearview camera failing to display when shifting into reverse, showing a blank/blue/black screen, or appearing only after a long delay. This issue is documented in owner complaints and overlaps with infotainment/display faults, but the safety impact is distinct because the camera is federally required equipment. In some cases the problem is intermittent, making it difficult to reproduce at the dealer.
Common Symptoms
- no rear camera image in reverse
- blue screen when backing up
- black screen when shifting into reverse
- camera image appears after several seconds
- guidelines missing or frozen
How to Fix
Check for related GM service bulletins, software updates, and camera/radio module faults. Diagnosis should include verifying camera power/ground, coax or video signal integrity, and whether the issue is isolated to the camera or part of a broader infotainment dropout. If software updates do not resolve it, dealers may replace the camera or radio/display components depending on test results.
Sources for this issue (1)
B127B code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does B127B mean on a Chevrolet?
B127B stands for "Rearview Camera Input Signal Circuit." B127B is a manufacturer-specific body code that generally indicates a problem with the rearview (backup) camera input signal circuit, meaning the display/control module is not receiving a proper video signal from the camera. The result is typically a blank, distorted, or missing rear camera image. It does not affect engine performance or drivability but reduces rear visibility assistance, so caution is advised when reversing. Exact meaning can vary by maker, so confirm with vehicle-specific data. On Chevrolet it is documented across 1 model: Trax.
What are the most common causes of B127B?
The most common causes of B127B are: Faulty rearview camera, Water intrusion or physical damage to the camera, Damaged or corroded camera wiring/connector, Open or short in the camera video signal circuit, Faulty display or infotainment/control module, Loss of power or ground to the camera. The specific cause varies by vehicle.
How much does it cost to fix B127B on a Chevrolet?
Repair costs vary widely with the root cause and Chevrolet model; each issue on this page carries its own estimate where one is published.
Looking for B127B on a different make?
View B127B across all makes →Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.