B2468

DTC B2468 Navigation Display ECU Internal Error:

CIRCUIT DESCRIPTION
The Navigation Display Module determines a majority of diagnostic failures. The Navigation Display Module sends the Navigation Data Processor a Diagnostic Memory Report when running through System Inspection Mode. This information includes Diagnostic Trouble Codes stored in a log by the Navigation Display Module. These failures occurred during normal operation and were reported to the Navigation Display Module for storage in this log.

CONDITIONS FOR RUNNING THE DTC
Navigation Display Module is running through System Inspection Mode.

CONDITIONS FOR SETTING DTC
^ ROM abnormality.
^ RAM abnormality.
^ V-RAM abnormality.
^ Back Light abnormality.
^ Back Light Heater abnormality.
^ Back Light Power Source abnormality.
^ LED Failure.
^ Switch Scanning abnormality.
^ Back Up Memory abnormality.
^ TV Power Source Voltage abnormality.
^ Internal Communication Error.
^ Chip Bus Request line shorted to ground.
^ Synchronous Signal abnormality.

ACTION TAKEN WHEN THE DTC SETS
^ Display will black out if DTC was set due to a Back Light abnormality or a Back Light Power Source abnormality.
^ Display appearance will change if DTC was set due to a Back Light Heater abnormality.
^ Non selected switch will remain active if DTC was set due to an LED Failure.
^ Unable to activate both hard and soft keys if DTC was set due to a Switch Scanning abnormality.
^ Back up contents will change if DTC was set due to a Back Up Memory abnormality.
^ TV Tuner will malfunction if DTC was set due to a RAM abnormality.
^ Unable to tune if DTC was set due to a TV Power Source Voltage abnormality.
^ Internal Communication Error appears on the display if DTC was set due to an Internal Communication Error.
^ Slow operation if DTC was set due to the Chip Bus Request line shorted to ground.
^ Blacked out display if DTC was set due to a Synchronous Signal abnormality.
^ This failure will have no effect outside the Navigation System.

CONDITIONS FOR CLEARING THE MIL/DTC
^ A current DTC will clear when the Navigation Display Module does not detect the failure during the last execution of the System Inspection Mode.
^ A history DTC will clear using a scan tool.

DIAGNOSTIC AIDS
^ An intermittent may be caused by the following:
- Mis-routed harness
- Rubbed through wire insulation
- Broken wire inside the insulation
^ Cycle the Ignition Switch even after a successful inspection with a scan tool so initialization will occur.
^ DTC B2468 will not set if DTC B1328, DTC B1327, or DTC U2150 is current.

TEST DESCRIPTION
The number(s) below refer to the step number(s) on the diagnostic table.
1. Determines if the malfunction is present.
2. Determines if the malfunction is due to an internal fault in the Navigation Display Module or a short to ground condition in circuit 1692.