Circuit/System Testing

Ignition OFF, disconnect the digital audio antenna coax from the A12 digital radio receiver and the T4H digital radio antenna.
Verify the digital radio antenna coax cable passes the coax cable component test. Refer to Component Testing.
- If the coax cable does not pass the test
  Replace the antenna coax cable
- If the coax cable passes the test
Replace the T4H digital radio antenna.
Ignition ON, A11 radio ON, tune to digital band.
Verify DTC B1259 is not set as current and digital reception is improved.
- If DTC B1259 is set as current or digital reception is not improved
  replace the A12 digital radio receiver.
- If DTC B1259 is not set as current and digital reception is improved
All OK.