B127A GMC Code - Auxiliary Video Input Signal Circuit
Quick Answer
The rear seat entertainment system has an auxiliary input assembly that contains a USB port, an SD card reader, RCA-type audio/video jacks, and a wired headphone jack with volume control. Common causes include Faulty Audio/Video Input Adapter, Audio/Video Input Adapter harness is open or shorted, Audio/Video Input Adapter circuit poor electrical connection. Severity is Low - monitor the vehicle and repair when practical. The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
- What it means
- B127A GMC indicates Auxiliary Video Input Signal Circuit.
- Common causes
- Common causes include Faulty Audio/Video Input Adapter, Audio/Video Input Adapter harness is open or shorted, Audio/Video Input Adapter circuit poor electrical connection.
- Severity
- Low - monitor the vehicle and repair when practical.
- Can I drive?
- The vehicle can usually be driven if no severe symptoms are present, but symptoms should be checked before extended driving.
Code B127A GMC Description
The USB port and SD card reader slot interface with a hub device, internal to the assembly. The assembly receives fused battery voltage and ground from the harness to power the internal hub device as well as provide additional amperage to power USB devices.
The internal hub device interfaces directly with the disc player via a standard USB cable. A Mini-type USB connector is used to connect the cable to the disc player and the auxiliary input assembly. Mini-type USB male-to-female connections are used for connecting USB cables together where an in-line connection is required. An in-line cable connection is typically found between the console and the I/P harness.
The USB port allows connectivity to the rear seat entertainment system from portable media players or a USB storage device (memory stick/ flash drive). The rear seat entertainment uses the SD card reader as a mass storage device, like a USB storage device.
Once a supported device is connected to the USB port or SD card reader, the device may be sourced to one or both of the rear displays using the remote control.
What are the Possible Causes of the DTC B127A GMC?
- Faulty Audio/Video Input Adapter
- Audio/Video Input Adapter harness is open or shorted
- Audio/Video Input Adapter circuit poor electrical connection
- Faulty Media Disc Player
How to Fix the DTC B127A GMC?
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 B127A GMC 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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Information for Specific GMC Models
- B127A 2014 GMC Sierra — Auxiliary Video Input Signal Circuit
- B127A 2015 GMC Sierra — Auxiliary Video Input Signal Circuit
- B127A 2016 GMC Sierra — Auxiliary Video Input Signal Circuit
- B127A 2017 GMC Sierra — Auxiliary Video Input Signal Circuit
- B127A 2018 GMC Sierra — Auxiliary Video Input Signal Circuit
Frequently Asked Questions about B127A GMC Code
1. What does the OBDII code B127A mean on a GMC vehicle?
The code B127A indicates an issue with the Auxiliary Video Input Signal Circuit, meaning the system is detecting a fault in the circuit that processes video input signals.
2. What are common symptoms of the B127A code?
Symptoms may include a non-functional auxiliary video input, no video display on the screen, or distorted video playback when using external devices.
3. What causes the B127A code to appear?
Common causes include damaged wiring, loose or corroded connectors, a faulty auxiliary video input port, or a malfunctioning multimedia control module.
4. Can I still drive my GMC with the B127A code active?
Yes, this code does not affect drivability, but it may prevent the auxiliary video input from functioning as intended.
5. How do I diagnose the B127A code on my GMC?
Start by inspecting the wiring and connectors for damage or corrosion. If no issues are found, test the auxiliary video input port and associated circuits with a multimeter or diagnostic scanner.
6. How can I fix the B127A code on my GMC?
Repairs may involve replacing damaged wiring, cleaning or reseating connectors, or replacing the faulty auxiliary video input port or multimedia control module.
7. Could a blown fuse cause the B127A code?
It’s possible if the fuse related to the multimedia system or auxiliary input is blown. Check the vehicle's fuse box and replace any blown fuses.
8. How much does it cost to repair the B127A code?
Repair costs vary depending on the issue. Minor fixes, like replacing a connector, may cost under $50, while replacing a multimedia module could cost several hundred dollars.
9. Can I clear the B127A code without repairing it?
Clearing the code with a scanner will temporarily erase it, but if the underlying issue isn’t fixed, the code will likely return.
10. Is the B127A code common in GMC vehicles?
It’s not a very common code, but it can occur in vehicles with auxiliary video input features, especially if the system or wiring is damaged.
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