2010 Cadillac CTS Sedan AWD V6-3.6L Page 183
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 video display 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 video display position
signal circuit to the navigation 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
All the below conditions are present for greater than 250 mS:
* The navigation radio detects a short to battery on the pop-up position sense circuit.
* The navigation radio detects a short to ground on the pop-up position sense circuit.
* The navigation radio detects an open on the pop-up position sense circuit
Action Taken When the DTC Sets
The Display Module Actuator is inoperative.
Reference Information
Schematic Reference
Radio/Navigation System Schematics (See: Accessories and Optional Equipment/Diagrams/Electrical Diagrams/Radio/Navigation System
Schematics)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Description and Operation
Radio/Audio System Description and Operation (See: Accessories and Optional Equipment/Description and Operation/Radio/Audio System
Description and Operation)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
Scan Tool Reference
Control Module References (See: Testing and Inspection/Programming and Relearning) for scan tool information
Circuit/System Testing
1. Ignition ON, place the navigation display in the down position.
2. Ignition OFF, disconnect the X4 harness connector at the radio.
3. Ignition ON, test for less than 1 volt between signal terminal 13 and ground.
