PRE-RELEASE
DTC B1020
| DTC B1020 |
| Diagnostic Instructions |
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Perform the
Diagnostic System Check - Vehicle
prior to using this diagnostic procedure.
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Review
Strategy Based Diagnosis
for an overview of the diagnostic approach.
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Diagnostic Procedure Instructions
provides an overview of each diagnostic category.
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| DTC Descriptor |
DTC B1020 00
Auxiliary Electronic Control Unit (ECU) Performance
| Circuit/System Description |
The radio communicates with the radio/HVAC control via serial data. This DTC indicates a fault in the radio/HVAC control. No external circuits are involved. The radio may continue to respond normally to faceplate functions when this DTC is set.
| Conditions for Running the DTC |
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Ignition is ON or in the ACC position.
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The system voltage is at least 9.5 V and no more than 15.5 V.
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All the above conditions are present for greater than 10 seconds.
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| Conditions for Setting the DTC |
The radio receives an improper status response indicating an internal ECU fault in the radio/HVAC control.
| Action Taken when the DTC Sets |
No action is taken.
| Conditions for Clearing the DTC |
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A current DTC clears when the radio receives a proper status response message back from the radio control assembly.
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A history DTC clears after 50 malfunction-free ignition cycles.
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| Diagnostic Aids |
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This DTC may be stored as a history DTC without affecting the operation ofthe radio/HVAC control.
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If stored only as a history DTC and not retrieved as a current DTC, do not replace the radio/HVAC control.
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If this DTC is retrieved as both a current and history DTC, replace the radio/HVAC control.
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| Reference Information |
Schematic Reference
Radio/Navigation System Schematics
Connector End View Reference
Component Connector End Views
Description and Operation
Radio/Audio System Description and Operation
Electrical Information Reference
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Circuit Testing
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Connector Repairs
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Testing for Intermittent Conditions and Poor Connections
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Wiring Repairs
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Scan Tool Reference
Control Module References for scan tool information
| Circuit/System Verification |
If this DTC is retrieved as a current DTC, replace the radio/HVAC control.
| Repair Instructions |
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
Control Module References for radio/HVAC control replacement, setup, and programming
