Internal error detection is determined inside the navigation radio. No external circuits are involved.
This diagnostic procedure supports the following DTC:
DTC B2468 Navigation Display Unit Performance
| • | The navigation radio performs this test when it detects a power mode transition to one of the following: | 
| - | ACC | 
| - | ON | 
| • | The navigation radio does not set this DTC if B1327 or B1328 is current . | 
The navigation radio is unable to write to memory and the test detects a computation error.
Any of the following may be observed:
| • | Black screen and the audio cannot be changed. | 
| • | The TV screen adjustment settings change to the default settings. | 
| • | The navigation screens may still be available. | 
The navigation radio is able to write to memory and there is no computation error when there is a power mode transition.
| • | This DTC may be stored as a history DTC with out affecting the operation of the module. If stored only as a history DTC and not retrieved as a current DTC, do not replace the module. | 
| • | If this DTC is retrieved as both a current and history DTC, replace the module. | 
The numbers below refer to the step numbers on the diagnostic table.
Determines if the malfunction is present.
Verifies that the DTC sets under normal operating conditions.
Step  | Action  | Yes  | No  | 
|---|---|---|---|
Did you perform the Diagnostic System Check - Vehicle?  | Go to Step 2  | ||
 Important: Do not operate any vehicle system for one minute. Is DTC B2468 a current DTC?  | Go to Step 3  | ||
3  | Replace the navigation radio. Refer to Control Module References . Did you complete the replacement?  | Go to Step 4  | --  | 
4  | 
 Does the DTC reset?  | Go to Step 2  | System OK  |