Circuit/System Testing
WARNING: This page does not describe the selected car, but rather 8 other vehicles, including the 2012 GMC Yukon XL, 2012 GMC Yukon, 2012 Chevrolet Tahoe, 2012 Chevrolet Suburban, and 2012 Chevrolet Avalanche. However, it is still accessible from the selected car via links, so may be relevant.
- Ignition OFF, disconnect the GPS and cell coax cable connector at the vehicle communication interface module.
- Using the EL-49903-3 kit (EL-49903-5 adapter and EL-49903-4 coax cable), connect the EL-49903 GM OnStar antenna diagnostic tool kit to the vehicle communication interface module, place the test antenna on the roof of the vehicle.
- Ignition ON, wait 5 minutes, then contact the OnStar call center consultant by pressing the blue OnStar button. A call center consultant should answer the call, ask the consultant to verify the vehicle location to confirm the GPS system is functioning.
- If the OnStar GPS does not function, replace the vehicle communication interface module.
- Ignition OFF, perform the coax cable test on the coax cable, refer to Component Testing. The coax cable should pass the test.
- If the coax cable does not pass the test, replace the coax cable.
- If all circuits test normal, replace the cellular and navigation antenna.