Circuit/System Testing

WARNING: This page is about a different car, the 2020 GMC Acadia. However, it is still accessible from the selected car via links, so may be relevant.

Ignition OFF, disconnect the coax cable connector at the T4T Wireless Communication Antenna - WLAN and at the A11 Radio.
Verify the coax cable passes the coax cable component test. Refer to Component Testing.
- If the coax cable does not pass the test
  Replace the coax cable
- Go to next step: If the coax cable passes the test
Test or replace the T4T Wireless Communication Antenna - WLAN.
Verify DTC B248A is not set.
- If DTC B248A is set
  Replace the A11 Radio.
- Go to next step: If DTC B248A is not set
All OK.