Buick Regal: DTC B1024 (Human Machine Interface Control Module)

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 B1024 53

Circuit Board Temperature Sensor Below Minimum Threshold

DTC B1024 54

Circuit Board Temperature Sensor Above Maximum Threshold

Circuit/System Description

The human machine interface control module monitors the internal circuitry for excessive temperature.

When a temperature outside of the range is detected, the module sets the DTC and limits its operation to avoid damage.

Conditions for Running the DTC

• Ignition On/Vehicle in Service Mode.
• The system voltage is 9-16 V
• The test is run once per second when the infotainment system is operating

Conditions for Setting the DTC

B1024 53

The module senses an internal temperature less than -40ºC (-40ºF).

B1024 54

The module senses an internal temperature greater than 69ºC (156ºF).

Action Taken When the DTC Sets

• The human machine interface control module sets the DTC.
• A message is displayed indicating that the system performance is being impacted by the excessive temperature condition.
• The module stops communicating on the MOST Bus network, but does not interrupt communication on the network.
• The infotainment system and the Info Display Module will have limited or no functionality.
• Components or other subsystems that interface with the infotainment system may have limited or no functionality.

Conditions for Clearing the DTC

• The internal temperature is between -40ºC (-40ºF) and 69ºC (156ºF).
• A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

Diagnostic Aids

Under certain conditions it may be normal for this DTC to set to prevent permanent damage to the module.

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

NOTE: Allow the vehicle cabin to cool if the temperature inside the vehicle is excessive before proceeding with this diagnostic procedure.

1. Verify the DTC sets outside of the Conditions for Running and Setting. Since most occurrences of this DTC are caused by extreme vehicle cabin temperatures due to ambient conditions, review with the customer the conditions under which the DTC set.

• If the DTC sets within the Conditions for Running and Setting.

The system is operating as designed, All OK.

• Go to next step: If the DTC sets outside the Conditions for Running and Setting.

2. Using the scan tool, clear the DTC.

3. Verify the DTC does not set while operating the infotainment system under the conditions the customer experienced the concern.

• If the DTC sets

Replace the K74 Human Machine Interface Control Module

• Go to next step: If the DTC does not set

4. All OK.

Repair Instructions

Refer to Control Module References for human machine interface control module replacement, programming, and setup.

Perform the Diagnostic Repair Verification after completing the repair.

DTC B1024 (Radio)

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 B1024

Circuit Board Temperature Sensor

Symptom Byte Information: Symptom Byte List.

Circuit/System Description

The internal module circuitry temperature is monitored. If the an over-heat condition which exceeds the maximum threshold of the internal circuitry or a malfunctioning temperature sensor is detected, the module will shut down until the internal circuitry cools.

Conditions for Running the DTC

• The radio is in the ON or ACCY position
• The system voltage is at least 9 volts and no more than 16 volts.

Conditions for Setting the DTC

The module detects an over-heat condition or a malfunctioning sensor.

Action Taken When the DTC Sets

Module functionality is suspended.

Conditions for Clearing the DTC

• A current DTC clears when the module temperature returns to an acceptable level.
• A history DTC clears after 100 malfunction-free ignition cycles.

Diagnostic Aids

Extended use of extremely high volume, especially in warm weather conditions, may cause this DTC to set in the Control module. Under these conditions, it may be normal for this DTC to set to prevent permanent damage to the Control module circuitry and no repair should be attempted.

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

Circuit/System Verification

NOTE: Allow the vehicle cabin to cool if the temperature inside the vehicle is excessive before proceeding with this diagnostic procedure.

1. Verify the DTC sets outside of the Conditions for Running and Setting. Since most occurrences of this DTC are caused by extreme vehicle cabin temperatures due to ambient conditions, review with the customer the conditions under which the DTC set.

• If the DTC sets within the Conditions for Running and Setting.

The system is operating as designed, All OK.

• Go to next step: If the DTC sets outside the Conditions for Running and Setting.

2. Using the scan tool, clear the DTC.

3. Verify the DTC does not set while operating the infotainment system under the conditions the customer experienced the concern.

• If the DTC sets

Replace the appropriate module.

• Go to next step: If the DTC does not set

4. All OK.

Repair Instructions

Refer to Control Module References for Control module replacement, setup, and programming.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.

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