B0997

DTC B0997

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.



DTC Descriptor
DTC B0997 00
- Auxiliary Electronic Control Unit (ECU) 2 Performance




Circuit/System Description

The navigation radio communicates with the Color Display Module over the CAN Graphical Interface (CGI) serial data circuit. The CGI circuit is a UART - based serial data interface used to transfer messages and high rate display graphics.


When the Color Display Module is in the active state, the radio needs to determine if the module is communicating properly. The radio initiates the Display Status Message to the module and waits for a proper status response message back from the module. If after 30 communication attempts without a proper response, the radio holds down the reset circuit in order to reset the module.


This DTC indicates an internal ECU fault of the Color Display Module located on the Display Module Actuator. No external circuits are involved.


Conditions for Running the DTC

* The ignition must be in the RUN or ACC position.
* The system voltage is at least 9.5 volts and no more than 15.5 volts.
* All the above conditions are present for greater than 10 seconds.



Conditions for Setting the DTC

The navigation radio receives an improper status response message back from the Color Display Module. Just before the navigation radio asserts the reset circuit, the DTC is set.


Conditions for Clearing the DTC

* A current DTC clears when the navigation radio receives the proper response message back from Color Display Module.
* A history DTC clears after 50 malfunction-free ignition cycles.



Reference Information
Schematic Reference

Radio/Navigation System Schematics (Radio/Navigation System Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Radio/Audio System Description and Operation (Radio/Audio System Description and Operation)
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information