DTC 128D

DTC 128D

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 Descriptors
DTC B128D 01
- Video Display Position Signal Short to Battery

DTC B128D 02
- Video Display Position Signal Short to Ground

DTC B128D 04
- Video Display Position Signal Open Circuit




Circuit/System Description

Pressing the NAV button, located on the Infotainment Faceplate Control Module or faceplate, sends a 5-volt signal on the popup position control circuit to the Display Module Actuator. The 5-volt signal sets the position of the Display Module Actuator commanding the display to the Up position. Pressing the NAV button again removes the signal on the circuit commanding the display to the Down position.


When the display is commanded to the Up position, the motor controller, located in the actuator, sends a 5-volt signal on the popup position sense circuit to the navigation radio. The circuit is a hard wired input from the motor controller to the radio. This signal is read by the radio in order to know which graphics to render on the touch-screen display.


Conditions for Running the DTC

The following are conditions that must be present in order for the navigation radio to enable diagnostics:

* 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.



Conditions for Setting the DTC

* • The navigation radio detects a short to battery on the popup position sense circuit.
* • The navigation radio detects a short to ground on the popup position sense circuit.
* • The navigation radio detects an open on the popup position sense circuit
* • All the above conditions are present for greater than 250 mS.



Action Taken When the DTC Sets

The Display Module Actuator is inoperative.


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