B2474

DTC B2474

Circuit Description

The backlighting error detection is determined inside the navigation radio. No external circuits are involved.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2474 Navigation Display Head (NDH) Backlighting Performance

Conditions for Running the DTC

* The navigation radio checks for a backlighting internal error every 5 seconds during the following power modes:

- ACC
- ACC
- ON

* DTC B2474 does not set if DTC B1328 or DTC B1327 is current.

Conditions for Setting the DTC

A B2474 sets if any of the following conditions are present:

* Backlighting circuit/bulb failure
* Backlighting circuit current consumption is too high.
* Backlighting heater is not providing heat.
* The navigation radio temperature is over 105°C (221°F).

Action Taken When the DTC Sets

Any of the following may be observed:

* Black screen and the audio and navigation functions cannot be controlled.
* The screen brightness is incorrect.
* Changes to the screen brightness are inconsistent.

Conditions for Clearing the DTC

The navigation radio determines that the backlighting fault is not present.

Diagnostic Aids

This DTC may be stored as a history DTC without affecting the operation of the navigation radio. If stored only as a history DTC and not a current DTC, do not replace the radio.

Test Description

Step 1 - Step 4:

The numbers below refer to the step numbers on the diagnostic table.
1. This step determines if the malfunction is present.
2. This step verifies that the DTC sets under normal operating conditions.