U2121
DTC U2121
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptor
DTC U2121
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No Communication with Radio Display
Circuit/System Description
The radio continuously sends a communication signal to the driver information display. Upon receiving the signal, the display sends a reply signal, confirming that it can communicate. The display is directly connects to the radio with no external circuits involved.
Conditions for Running the DTC
The radio is active.
Conditions for Setting the DTC
The radio does not receive a response from the radio display for 10 or more consecutive seconds.
Action Taken When the DTC Sets
The system will set the DTC and disable itself.
Conditions for Clearing the DTC
* The current DTC will clear when the radio receives a communication reply from the driver information display.
* The history DTC will clear after 50 fault-free ignition cycles have occurred.
Diagnostic Aids
Physically check that the driver information display is correctly mounted to the radio.
Reference Information
Schematic Reference
Radio/Navigation System Schematics Radio/Navigation System Schematics
Connector End View Reference
Component Connector End Views Fuel Pump and Level Sensor Assembly
Description and Operation
Radio/Audio System Description and Operation Radio/Audio System
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Verification
1. Verify that DTC U2121 is not set.
• If the DTC is set, replace the driver information display. If the DTC resets, replace the radio.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
Control Module References Control Module References for radio and driver information display replacement, setup, and programming