Volt

Radio Poor Reception

The AM/FM aerial is part of the multi-band aerial is located on the roof of the vehicle. The radio provides battery voltage to the AM/FM amplifier in the aerial base using the centre conductor of the aerial coaxial cable. When a 12 V signal is seen by the amplifier, both AM and FM signals are amplified.

Schematic Reference

Radio/Navigation System Schematics

Connector End View Reference

Component Connector End Views

Description and Operation

Radio/Audio System Description and Operation

Electrical Information Reference

Scan Tool Reference

Control Module References for scan tool information

Vehicle in Service Mode, radio ON, tune to a strong AM or FM station. Verify that the AM and FM reception is clear.

1. Vehicle OFF, disconnect the radio aerial coax from the A11 radio and the T4G aerial.
2. Test for infinite resistance between the aerial coax centre terminal and ground.

⇒	If less than the specified value, replace the aerial coax.

3. Test for infinite resistance between the coax centre terminal and the outer shield.

⇒	If less than the specified value, replace the aerial coax.

4. Test for less than 5 Ω on the aerial coax centre circuit from end to end.

⇒	If greater than the specified range, replace the aerial coax.

5. Vehicle in Service Mode, test for less than 1 V between the aerial coax centre terminal and ground.

⇒	If greater than the specified range, replace the aerial coax.

6. Connect the aerial coax to the A11 radio. Test for 12-15 V between the aerial coax centre terminal and ground at the T4G aerial connector.

⇒	If not within the specified range, replace the A11 radio.

7. If all circuits test normal, replace the T4G aerial.

Perform the Diagnostic Repair Verification after completing the diagnostic procedure.