No Global Positioning System (GPS) Reception

No Global Positioning System (GPS) Reception

Diagnostic Instructions

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

Circuit Description

The global positioning system (GPS) antenna is connected to the navigation radio by a shielded coaxial cable. The GPS antenna is powered through the same coaxial cable used to send signals to the navigation system. The antenna cable also provides a path for DC current for powering the GPS antenna.

Circuit/System Testing

Important: The global positioning system (GPS) requires a clear line of sight to the sky to operate properly. In most cases the GPS will not have reception near tall buildings or inside structures.

1. Ignition OFF, disconnect the coax harness connectors at the navigation radio and the GPS antenna.
2. Test for less than 5 ohms between the two ends of the coax cable center conductor.

^ If greater than the specified range, replace the GPS antenna coax cable.

3. Test for less than 5 ohms between the two ends of the coax cable outer shield.

^ If greater than the specified range, replace the GPS antenna coax cable.

4. Test for infinite resistance between the coax center conductor and the outer shield.

^ If less than the specified range, replace the GPS antenna coax cable.

5. Connect the coax harness connector at the navigation radio.
6. Ignition ON, test for 4.0-5.5 volts between the coax center conductor and the outer shield.

^ If not within the specified range, replace the navigation radio.

7. If all circuits test normal, replace the GPS antenna.

Repair Instructions

Perform the Diagnostic Repair Verification after completing the diagnostic procedure. Verification Tests

* Global Positioning System (GPS) Antenna Replacement