GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The global positioning system (GPS) antenna is connected to the navigation radio by a coaxial cable.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B2462 Global Positioning System (GPS) Error

This vehicle has DTCs which include DTC symptoms. For more information on DTC symptoms, refer to DTC Symptom Description in Vehicle DTC Information.

DTC Symptom

DTC Symptom Descriptor

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
    • RAP UNLK

DTC B2462 does not set if DTC B1328 or B1327 is current.

Conditions for Setting the DTC

    • The navigation radio test the GPS antenna every 10 seconds.
    • The radio determines there is an open in the GPS antenna.
    • DTC B2462 does not set if DTC B1328 or B1327 is current.

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.
    • This failure has no effect outside the navigation system.

Conditions for Clearing the DTC

    • A current DTC clears when the radio does not detect the failure for more than 10 seconds.
    • A history DTC clears after 50 ignition cycles with no repeat of the failure.

Diagnostic Aids

An intermittent condition may be caused by the following:

    • Mis-routed harness
    • Rubbed through wire insulation
    • Broken wire inside the insulation

Test Description

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

  1. Determines if the malfunction is present.

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

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. Turn OFF the ignition.
  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 within the specified range?

4.0-5.5 V

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 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 GPS cable. 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 GPS antenna. Refer to Global Positioning System (GPS) Antenna Replacement .

Did you complete the replacement?

--

Go to Step 7

--

6

Replace the navigation radio. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

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 within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK