Schematic Reference: Radio/Audio System Schematics

Always perform the Radio/Audio System Diagnostic System Check before proceeding with these diagnostic procedures. Refer to Diagnostic System Check - Entertainment System .

Important: The following information lists the most probable cause of the concern to the least probable cause followed by the appropriate test for that condition. If the list leads to the replacement of a component, always inspect for a poor connection before proceeding with the replacement. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

With RPO UM8 (navigation)

1. Speaker output shorted - Test all speaker outputs for a short. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
2. Defective radio - Replace the radio. Refer to Radio Replacement .

Without RPO UM8

1. Low level audio signal circuit shorted. Test all low level audio signal circuits for a short to ground or short to voltage. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Important:: Reprogram the radio. Refer to Service Programming System (SPS) .

2. No low level audio output from the radio. Test for any AC voltage between the left front low level audio signal circuits at the amplifier harness connector, disconnected with the radio volume adjusted to 50%. If no AC voltage is present, replace the radio. Refer to Radio Replacement .
3. No audio output from the amplifier. Replace the amplifier. Refer to Radio Speaker Amplifier Replacement .

Important: The following procedure assumes all speakers are operative for all modes of operation except digital radio.

With RPO U2K

1. Remote radio audio signal circuit shorted -- Test the remote radio audio signal circuits for a short. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
2. No audio output from the digital radio receiver -- Replace the digital radio receiver. Refer to Digital Radio Receiver Replacement .
3. No digital radio audio output from the radio -- Replace the radio. Refer to Radio Replacement .

Important: The following information lists the most probable cause of the concern to the least probable cause. If the list leads to the replacement of a component, always inspect for a poor connection before proceeding with replacement. Refer to and in Wiring Systems.

Important: The following procedure assumes all speakers are operative for all modes of operation except digital radio.

With RPO U2K

1. Remote radio audio signal circuit open -- Test the appropriate remote radio audio signal circuit for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
2. No audio output from the digital radio receiver -- Replace the digital radio receiver. Refer to Digital Radio Receiver Replacement .
3. No digital radio audio output from the radio -- Replace the radio. Refer to Radio Replacement .

Important: The following information lists the most probable cause of the concern to the least probable cause. If the list leads to the replacement of a component, always inspect for a poor connection before proceeding with replacement. Refer to Testing for Intermittent Conditions and Poor Connections and Connector Repairs in Wiring Systems.

With RPO UM8

1. Speaker output open. Test the appropriate speaker output circuits for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
2. No audio output from the radio. Test for any AC voltage between the appropriate speaker output circuits at the speaker harness connector, disconnected with the radio volume adjusted to an audible level. If AC voltage is present, replace the speaker. Refer to Speaker Replacement Reference . If no AC voltage is present, replace the radio. Refer to Radio Replacement .

Without RPO UM8 or UQA

1. Speaker output open. Test the appropriate speaker output circuits for an open. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.

Important:: Reprogram the radio. Refer to Service Programming System (SPS) .

2. No audio output from the radio. Test for any AC voltage between the appropriate speaker output circuits at the speaker harness connector, disconnected with the radio volume adjusted to an audible level. If AC voltage is present, replace the speaker. Refer to Speaker Replacement Reference . If no AC voltage is present, replace the radio. Refer to Radio Replacement .

With RPO UQA (Bose)

1. Speaker output circuit from amplifier open or shorted. Test the appropriate speaker output circuits for an open or short. Refer to Circuit Testing and Wiring Repairs in Wiring Systems.
2. No audio output from the amplifier. Test for any AC voltage between the appropriate speaker output circuits at the speaker harness connector, disconnected with the radio volume adjusted to an audible level. If AC voltage is present, replace the speaker. Refer to Speaker Replacement Reference . If no AC voltage is present, replace the amplifier. Refer to Radio Speaker Amplifier Replacement .