Buick Regal: Radio Controls Malfunction (IOB)
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.
Diagnostic Fault Information
1. Home, Seek Up, Seek Down, and/or Phone button will not function
2. Power Button will not function
3. Unable to adjust volume
4. All Radio Control buttons may not function
Circuit/System Description
The radio info display module, radio controls and radio are all separate
components. The radio controls
communicate radio control inputs directly to the radio through a discrete
circuit for volume up, volume
down and power ON button. It also uses a series of resistors through a single
signal circuit when the
home, seek up, seek down and phone buttons are pressed. After receiving the
message the radio will
perform the requested function. The info display module receives digital video
data from the radio for
on-screen display information through the LVDS (Low Voltage Differential Signal)
cable. The radio
communicates with the info display module over the radio display touch interrupt
request signal for
touch screen inputs.
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.
Circuit/System Verification
1. Verify DTC B123E is not set.
Refer to Diagnostic Trouble Code (DTC) List - Vehicle
- Go to next step: If DTC B123E is not set
2. Ignition ON/vehicle in Service Mode, A11 Radio ON.
3. Verify that all radio controls operate and perform the correct function.
- If all or some of the radio controls are inoperative
Refer to Circuit/System Testing.
- Go to next step: If all radio controls operate and perform the
correct function.
4. All OK.
Circuit/System Testing
1. Ignition OFF/vehicle OFF, disconnect the harness connector at the A22
Radio Controls.
2. Test for less than 10 Ω between the following low reference circuit terminals
and ground.
- terminal 2
- terminal 8
- If 10 Ω or greater
- Disconnect the X1 harness connector at the P17 Info Display Module.
- Test for less than 2 Ω in the low reference circuits end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the P17 Info Display Module.
- Go to next step: If less than 10 Ω
3. Ignition ON/vehicle in Service Mode, test for 2.5 - 3.5 V between the
following signal circuit
terminals and ground:
- terminal 3
- terminal 4
- terminal 6
- terminal 7
- If less than 2.5 V
- Ignition OFF/vehicle OFF, disconnect the X2 harness connector at the A11
Radio.
- Test for infinite resistance between the control circuit and ground.
- If less than infinite resistance, repair the short to ground on the
circuit.
- Go to next step: If infinite resistance
- Test for less than 2 Ω on the control circuit end to end.
- If 2 Ω or greater, repair the open/high resistance in the circuit.
- If less than 2 Ω, replace the A11 Radio.
- Ignition OFF/vehicle OFF, disconnect the X2 harness connector at the A11
Radio.
- Test for less than 1 V between the control circuit and ground
- If greater than 1 V, repair the short to voltage in the circuit.
- If less than 1 V, replace the A11 Radio.
- Go to next step: If between 2.5 - 3.5 V
4. Replace the A22 Radio Controls
Repair Instructions
Perform the Diagnostic Repair Verification after completing the repair.
Control Module References for radio or radio control assembly 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
SEE MORE:
REPAIRS AND INSPECTIONS REQUIRED AFTER A COLLISION
WARNING: Restraint systems can be damaged in a collision. To help
avoid injury and ensure that all parts in need of replacement are replaced:
Replace any seat belt system that was in use during the collision
serious enough to deploy any automati
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