LEMON Manuals: Even more car manuals for everyone: 1960-2025
Home >> Cadillac >> 2003 >> Escalade EXT >> Repair and Diagnosis >> External Pages >> Different car >> Section 647 (Navigation Systems) >> Diagnostic Information and Procedures >> DTC U2153: VICS ECU Communication Error >> Test Description
April 5, 2026: LEMON Manuals is launched! Read the announcement.

Test Description

WARNING: This page is about a different car, the 2004 Cadillac CTS. However, it is still accessible from the selected car via links, so may be relevant.

The number(s) below refer to the step number(s) on the diagnostic table.

  1. 1:  Determines if the malfunction is present.
  2. 2:  Verifies that the DTC sets under normal operating systems.
DTC U2153

Step Action Yes No
Schematic Reference:  Navigation System Schematics  
Connector End View Reference: Navigation System Connector End Views 
Did you perform the Diagnostic System Check - Navigation System? Go to Step 2  Go to Diagnostic System Check - Navigation System 
  1. Turn OFF the ignition.
  2. Open, then close driver door to cancel RAP.
    IMPORTANT: Do not operate any vehicle system for one minute.
  3. Connect a scan tool.
  4. Turn ON the ignition with engine off.
  5. Retrieve DTCs from the navigation radio.
Does the DTC reset?
Go to Step 3  Go to Diagnostic System Check - Navigation System 
3 Test the VICS (+) circuit for the following:
  • An open
  • A short to ground
  • A short to voltage
  • High resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 9  Go to Step 4 
4 Test the VICS (-) circuit for the following:
  • An open
  • A short to ground
  • A short to voltage
  • High resistance

Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 9  Go to Step 5 
5 Inspect for poor connections at the harness connectors of the VICS Module Assembly. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 9  Go to Step 6 
6 Inspect for poor connections at the harness connectors of the navigation radio. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.
Did you find and correct the condition?
Go to Step 9  Go to Step 7 
7 Replace the VICS Module Assembly. Refer to the VICS dealer installation instructions.
Did you find and correct the condition?
Go to Step 9  Go to Step 8 
8 Replace the navigation radio. Refer to Radio Replacement in Entertainment.
Did you complete the repair?
Go to Step 9  -
9
  1. Use the scan tool to clear the DTCs.
  2. Operate the vehicle as specified within the Conditions for Running the DTC in the supporting text.
Does the DTC reset?
Go to Step 2  System OK