GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The navigation radio supplies power to the TV antenna module to permit the selection of the antenna set used. The radio tests the antenna select supply voltage circuit every 500 ms after the ignition is cycled to ON. The radio does this by monitoring the current draw on the antenna select supply voltage circuit.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2460 Navigation Antenna Selector Circuit High Current

Conditions for Running the DTC

    • The navigation radio must detect a power mode transition from OFF-ASLEEP to either:
       - ACC
       - ON
    • The vehicle must be equipped with the navigation system with TV option (RPO UE7).
    • The navigation radio does not set this DTC if DTC B1327 or DTC B1328 is current.

Conditions for Setting the DTC

    • Current draw of the TV antenna module exceeds the regular value.
    • The antenna select supply voltage circuit shorted to ground.
    • DTC B2460 does not set if DTC B1328 or DTC B1327 is current.

Action Taken When the DTC Sets

    • TV video unclear, grey screen
    • TV audio unclear, full of static

This failure has no effect outside the TV function of the navigation system.

Conditions for Clearing the DTC

A current DTC clears when the navigation radio does not detect the failure for more than 500 ms.

Diagnostic Aids

An intermittent condition may be caused by the following:

    • Mis-routed harness
    • Rubbed through wire insulation

Test Description

The numbers below refer to the step numbers on the diagnostic table.

  1. Determines if the malfunction is present.

  2. Tests the antenna select supply voltage.

Step

Action

Value(s)

Yes

No

Schematic Reference: Navigation System Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

  1. Disconnect the TV antenna module.
  2. Turn ON the ignition with the engine OFF.
  3. Measure the voltage of the antenna select supply voltage circuit.

Is the voltage within the specified range?

0.3-1.0 V

Go to Step 5

Go to Step 3

3

Test the antenna select supply voltage circuit for a short to ground. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 7

Go to Step 4

4

Inspect for poor connections at the harness connector 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 7

Go to Step 6

5

Replace the TV antenna module assembly. Refer to Television Antenna Module Replacement .

Did you complete the replacement?

--

Go to Step 7

--

6

Replace the navigation radio. Refer to Control Module References in Computer/Integrating Systems.

Did you complete the replacement?

--

Go to Step 7

--

7

  1. Use the scan tool in order to clear the DTC.
  2. Operate the vehicle according to the Conditions for Running the DTC in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK