B1259

DTC B1259

Circuit Description

The digital radio antenna is connected to the digital radio receiver (DRR) by 2 coax cables. One coax carries the satellite signal, the other coax carries the terrestrial signal. The antenna cable for the satellite antenna also provides a path for DC current for powering the antenna.

DTC Descriptor

This diagnostic procedure supports the following DTC:

DTC B1259 Antenna Ground Circuit

Conditions for Running the DTC

This test is run every 300 milliseconds.

Conditions for Setting the DTC

The DRR detects an antenna fault.

Action Taken When the DTC Sets

The radio displays No XM Signal.

Conditions for Clearing the DTC

* The condition must be corrected.
* The DTC clears after 100 malfunction free ignition cycles.

Test Description

Step 1 - Step 10:

The numbers below refer to the step numbers on the diagnostic table.
2. Early design modules support the mV reading while later design modules support the mA reading.
3. Due to current limiting capabilities in the module, an antenna cable shorted to ground could still show 1,200-1,800 mV.