GM Service Manual Online
For 1990-2009 cars only
Makes 🢒 Cadillac 🢒 2007 🢒 CTS 🢒 Driver Information and Entertainment 🢒 Cellular, Entertainment, and Navigation 🢒 DTC U2153

Diagnostic Instructions
    • Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
    • Review Strategy Based Diagnosis for an overview of the diagnostic approach.
    •  Diagnostic Procedure Instructions provides an overview of each diagnostic category.

DTC Descriptor

DTC U2153: Navigation Electronic Control Unit (ECU) - VICS Communication Circuit

Circuit Description

The vehicle information communication system (VICS) Module Assembly communicates with the navigation radio over 2 circuits. These are the VICS (+) circuit, and the VICS (-) circuit.

Diagnostic Aids

The vehicle must be equipped with the VICS Module Assembly. This system is available only on export vehicles and is dealer installed.

Conditions for Running the DTC
    • The radio is ON.
    • Battery voltage must be between 9-16 volts.
    • The navigation radio does not set this DTC if B1327 or B1328 is current.

Conditions for Setting the DTC

There is no response from the VICS module when queried by the navigation radio after successfully initializing the system.

The navigation radio does not receive information from the VICS module when the radio detects a power mode transition to ON.

Actions Taken When the DTC Sets

The VICS switch disappears from the navigation system menu.

Conditions for Clearing the DTC
    • The condition responsible for setting the DTC no longer exists.
    • A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

Reference Information

Schematic Reference

Radio/Navigation System Schematics

Connector End View Reference

Entertainment/Communication Connector End Views

Description and Operation

Radio/Audio System Description and Operation

Electrical Information Reference

    •  Circuit Testing
    •  Connector Repairs
    •  Testing for Intermittent Conditions and Poor Connections
    •  Wiring Repairs

Circuit/System Testing
  1. Ignition OFF, disconnect the harrness connector at the Traffic Information Receiver.
  2. Test for less than 10 ohms between the ground circuit terminal F and ground.
    3. ⇒If greater than specified range, test the circuit for an open/high resistance.
  3. Ignition ON, test for B+ between the battery positive voltge circuit terminal E and ground.
    4. ⇒If less than specified range, test the circuit for an short to ground or an open/high resistance.
  4. Ignition ON, test for B+ between the switched antenna enable signal circuit terminal D and ground.
    5. ⇒If less than specified range, test the circuit for an short to ground or an open/high resistance. If the circuit tests normal, replace the radio.
  5. Ignition OFF, dissconnect the C4 harness connector at the radio.
  6. Test for less than 5 ohms between the following terminals on the same circuit:
    7. • Navigation Display Serial Data Low - Terminal 15 at the radio and terminal B at the Traffic Information Receiver.
    • Navigation Display Serial Data High - Terminal 16 at the radio and terminal A at the Traffic Information Receiver.
    ⇒ If greater than the specified range, test the serial data circuit for an open/high resistance.
  7. If all circuits test normal, replace the Traffic Information Receiver.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.