GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The GPS antenna is connected to the navigation radio by a coaxial cable.

DTC Descriptor

The diagnostic procedure supports the following DTCs:

DTC B 2462 Global Positioning System (GPS) Error

The vehicle has DTCs including the DTC symptoms. Refer to DTC Symptom Description for DTC information.

DTC Symptom

DTC Symptom Description

02

Short to ground

04

Open circuit

Conditions for Running the DTC

The radio must detect one of the following power modes:

    • ACC
    • ON
    • RAP
    • RAPUNLK
        If DTC B 1328 or B 1327 is current, DTC B 2462 does not set.

Conditions for Setting the DTC

    • The navigation radio tests the GPS antenna every 10 seconds.
    • The radio determines there is an open in the GPS antenna.
    • If DTC B 1328 or B 1327 is current, DTC B 2462 does not set.

Action Taken When the DTC Sets

    • Unable to get GPS location updated, the radio uses the last reported position and the vehicle speed signal to calculate the vehicle position.
    • Route guidance may be inaccurate.
    • The malfunction does not affect other systems except navigation system.

Conditions for Clearing the DTC

    • A current DTC clears when the radio does not detect the failure for more than 10 seconds.
    • The history DTC clears after 50 malfunction-free ignition cycles.

Diagnostic Aids

The following conditions may cause an intermittent malfunction:

    • Wiring Fault
    • Wire insulation which is rubbed through
    • Wiring broken inside the insulation

Test Description

The following numbers are corresponding to the steps in the diagnostic table.

  1. Inspect if a malfunction exists.

  2. Determines if the malfunction is due to an internal fault in the navigation radio or a GPS antenna failure.

Step

Operation

Value

Yes

No

Schematic Reference: Radio/Navigation System Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go To Step 2

Go to Diagnostic System Check - Vehicle

2

  1. Place the ignition switch in OFF position.
  2. Disconnect the global positioning system (GPS) coaxial cable connector.
  3. Measure the voltage between the center conductor and the shield of the coaxial cable still attached to the navigation radio.

Is the voltage measured within the specified value?

4.0-5.5V

Go to Step 5

Go To Step 3

3

Test the GPS cable for an open or short to ground. Refer to Circuit Testing and Wiring Repairs .

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 GPS. Refer to Testing for Intermittent Conditions and Poor Connections .

Did you find and correct the condition?

--

Go To Step 7

Go To Step 6

5

Replace the GPS antenna. Refer to Electronic Navigation Antenna Replacement .

Is the replacement complete?

--

Go To Step 7

--

6

Replace the navigation radio. Refer to Control Module References for replacement, set, and programming.

Is the replacement complete?

--

Go To Step 7

--

7

  1. Clear the DTCs with the scan tool.
  2. Operate the vehicle under conditions when DTC runs as specified in supporting documents.

Does the DTC set again?

--

Go To Step 2

System is OK