GM Service Manual Online
For 1990-2009 cars only

Circuit Description

The digital radio antenna is connected to the digital radio receiver (DRR) by a coax cable. This cable carries the satellite and the terrestrial signal. The antenna cable 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.

Step

Action

Values

Yes

No

Schematic Reference: Radio/Audio System Schematics

1

Did you perform the Diagnostic System Check - Vehicle?

--

Go to Step 2

Go to Diagnostic System Check - Vehicle in Vehicle DTC Information

2

With a scan tool, observe the digital radio antenna in the digital radio receiver (DRR) data list.

Does the scan tool indicate that the digital radio antenna is within the specified range?

17-63 mA

Go to Step 6

Go to Step 3

3

  1. Disconnect the antenna cable from the DRR.
  2. Measure the voltage from the center conductor of the antenna connector on the DRR to one of the case screws.

Does the voltage measure within the specified range?

4.5-5.5 V

Go to Step 4

Go to Step 6

4

Test the antenna cable for an open or a high resistance. Refer to Circuit Testing in Wiring Systems.

Did you find the condition?

--

Go to Step 5

Go to Step 8

5

Replace the antenna cable. Refer to Digital Radio Antenna Cable Replacement .

Did you complete the replacement?

--

Go to Step 10

--

6

Inspect for poor connections at the DRR. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 7

7

Replace the DRR. Refer to Control Module References in Computer/Integrating Systems for replacement, setup, and programming.

Did you complete the replacement?

--

Go to Step 10

--

8

Inspect for poor connections at the digital radio antenna. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

Did you find and correct the condition?

--

Go to Step 10

Go to Step 9

9

Replace the digital radio antenna. Refer to Digital Radio Antenna Replacement .

Did you complete the replacement?

--

Go to Step 10

--

10

  1. Use the scan tool in order to clear the DTCs.
  2. Operate the vehicle within the Conditions for Running the DTC as specified in the supporting text.

Does the DTC reset?

--

Go to Step 2

System OK