Buick Regal: DTC B127E (IO6)
Diagnostic Instructions
- Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
- Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
- Refer to Diagnostic Procedure Instructions for an overview of each
diagnostic category.
DTC Descriptor
DTC B127E 00
Front Video Display Output Signal
Circuit/System Description
The infotainment display and controls are a separate component from the
radio, combined into an
assembly. The assembly is supplied battery voltage and ground from the vehicle
harness. The human
machine interface control module communicates digital video data for on-screen
display through a
dedicated cable containing the LVDS data circuits.
Control information, touch communications and dimming level for the display are
communicated via a
LIN serial data circuit to the human machine interface control module.
If the human machine interface control module detects the display is not
responding to the output on the
LVDS circuits, the human machine interface control module sets the DTC.
Conditions for Running the DTC
- Ignition is ON or in the ACC position
- The system voltage is 9-16 V
- The infotainment system is ON
- The test is continuously when the infotainment system is operating
Conditions for Setting the DTC
The human machine interface control module detects the display is not
responding to the output on the
LVDS circuits.
Action Taken When the DTC Sets
- The human machine interface control module sets this DTC
- No images are shown on the Info Display Module
Conditions for Clearing the DTC
- The human machine interface control module detects a properly synced
digital video signal.
- A history DTC will clear once 50 consecutive malfunction-free ignition
cycles have occurred.
Reference Information
Schematic Reference
Radio/Navigation System Wiring Schematics (IOB) , Radio/Navigation System
Wiring Schematics
(IOR) or Radio/Navigation System Wiring Schematics (IO5/IO6) , or
Radio/Navigation System
Wiring Schematics (IOS/IOT).
Connector End View Reference
Component Connector End View Index
Description and Operation
Radio/Audio System Description and Operation (IO6) , Radio/Audio System
Description and Operation (IOB) , or Radio/Audio System Description and
Operation (IOS/IOT/IOU).
Electrical Information Reference
- Refer to Circuit Testing
- Refer to Connector Repairs
- Refer to Testing for Intermittent Conditions and Poor Connections
- Refer to Wiring Repairs
Scan Tool Reference
Control Module References for scan tool information.
Special Tools
- EL-50334 - 2 Type A female to Mini B male USB Cable
- EL-50334 - 14 Infotainment Test Cable
Circuit/System Testing
1. Vehicle OFF/Ignition OFF.
2. Verify the LVDS interface cable is properly connected at the P17 Info Display
Module and the
K74 Human Machine Interface Control Module connections and there is no damage to
the cable
or connections.
3. Ignition ON/Vehicle in Service Mode, infotainment system ON.
4. Verify the P17 Info Display Module does not display an image.
- If the P17 Info Display Module displays an image.
All OK.
- Go to next step: If the P17 Info Display Module does not display an
image
5. Vehicle OFF/Ignition OFF.
6. Disconnect the LVDS interface cable from the P17 Info Display Module.
7. Connect the EL-50334-2 Type A female to Mini B male USB Cable to the P17 Info
Display
Module. Connect the EL-50334-14 Infotainment Test Cable to the adapter.
8. Disconnect the LVDS interface cable from the K74 Human Machine Interface
Control Module.
Connect the EL-50334 - 14 Infotainment Test cable to the K74 Human Machine
Interface Module.
9. Ignition ON/Vehicle in Service Mode, infotainment system ON.
10. Verify the P17 Info Display Module displays an image.
- If the P17 Info Display Module does not display an image
- Replace the P17 Info Display Module. Connect all harness connectors.
- Ignition ON/Vehicle in Service Mode, infotainment system ON.
- Verify the P17 Info Display Module displays an image.
- If the P17 Info Display Module still does not display an image,
replace the K74 Human Machine Interface Control Module.
- Go to next step: If the P17 Info Display Module displays an image.
- All OK.
- Go to next step: If the P17 Info Display Module displays an image.
11. Replace the vehicle LVDS interface cable from the P17 Info Display Module
to the K74 Human
Machine Interface Module.
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
- Refer to Radio Control Assembly Replacement (IOB) or Radio Control
Assembly
Replacement (IO5, IO6)
- Refer to Control Module References for human machine interface control
module replacement,
programming, and setup.
READ NEXT:
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Refe
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Refe
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Refe
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Transfer Case
Under normal driving conditions,
transfer case fluid does not require
maintenance unless there is a fluid
leak or unusual noise. If required,
have the transfer case serviced by
your dealer.
Starter Switch Check
Warning:
When you are doing this
inspection, the vehicle could
move suddenl
Diagnostic Instructions
Perform the Diagnostic System Check - Vehicle prior to using this
diagnostic procedure.
Review Strategy Based Diagnosis for an overview of the diagnostic
approach.
Diagnostic Procedure Instructions provides an overview of each
diagnostic category.
DTC Descriptor
DT