Schematic Reference: Radio/Navigation System Schematics

Always perform the Diagnostic System Check - Vehicle before proceeding with these diagnostic procedures. Refer to Diagnostic System Check - Vehicle .

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 .

With RPO UQ2

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

With RPO U85

1. Battery positive voltage circuit to the amplifier open--Test the battery positive voltage circuit to the amplifier for an open. Refer to Circuit Testing and Wiring Repairs .
2. Amplifier control circuit to the amplifier open or shorted to ground--Test amplifier control circuit for an open or short to ground. Refer to Circuit Testing and Wiring Repairs .
3. 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 percent. If no AC voltage is present, replace the radio. Refer to Radio Replacement .
4. 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 or U2L

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

With RPO UQ2

1. Speaker output open--Test the appropriate speaker output circuits for an open. Refer to Circuit Testing and Wiring Repairs .
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 50 percent. 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 U85

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 .
2. Low level audio circuit open--Test the appropriate low level audio circuit for an open. Refer to Circuit Testing and Wiring Repairs .
3. No low level audio output from the radio--Test for any AC voltage between the appropriate low level audio signal circuits at the amplifier harness connector, disconnected with the radio volume adjusted to 50 percent. If no AC voltage is present, replace the radio. Refer to Radio Replacement .
4. 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 50 percent. 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 .

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 .

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

With RPO U2K or U2L

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 .
2. No audio output from the digital radio receiver--Replace the digital radio receiver.
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 .

With RPO UQ2

1. Speaker output circuit high resistance--Test the appropriate speaker output circuits for high resistance. Refer to Circuit Testing and Wiring Repairs .
2. Defective speaker--Replace the appropriate speaker. Refer to Speaker Replacement Reference .

With RPO U85

1. Speaker output circuit high resistance--Test the appropriate speaker output circuits for high resistance. Refer to Circuit Testing and Wiring Repairs .
2. Gain control signal circuit short to ground--Test the gain control signal circuit for a short ground. Refer to Circuit Testing and Wiring Repairs .
3. Low level audio circuit open--Test the appropriate low level audio circuit for an open. Refer to Circuit Testing and Wiring Repairs .
4. Defective speaker--Replace the appropriate speaker. Refer to Speaker Replacement Reference .

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

With RPO U2K or U2L

1. Audio common circuit open or short to battery positive voltage--Test the audio common circuit for an open or short to battery positive voltage. Refer to Circuit Testing and Wiring Repairs .
2. No audio output from the digital radio receiver--Replace the digital radio receiver.
3. No digital radio audio output from the radio--Replace the radio. Refer to Radio Replacement .