Schematic Reference: 
Radio/Audio System Schematics  
Preliminary Information
Perform the 
Diagnostic System Check - Entertainment System 
 .
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 to
Connector Repairs 
 in Wiring Systems.
All Speakers Inoperative
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 
Circuit Testing 
 and 
Wiring Repairs 
 in Wiring
Systems.
With RPO UM8
- 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 
in Wiring Systems.
 
- Ground circuit to the amplifier open. Test the ground circuit to the amplifier
for an open. Refer to 
Circuit Testing 
 and
Wiring Repairs 
 in Wiring Systems.
 
- Speaker output from the radio shorted. Test each speaker output of the
radio for a short to ground or short to voltage. Refer to 
Circuit Testing 
 and 
Wiring Repairs 
in Wiring Systems.
 
- No audio output from the amplifier. Replace the amplifier. Refer to 
Radio Speaker Amplifier Replacement 
.
 
One Speaker Inoperative
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 
Circuit Testing 
 and 
Wiring Repairs 
 in Wiring Systems.
Without RPO UM8
- Speaker output circuit from amplifier open. Test the appropriate speaker
output circuits for an open. Refer to 
Circuit Testing 
and 
Wiring Repairs 
 in Wiring Systems.
 
Important: The radio must be programmed after replacement. Refer to 
Service Programming System (SPS) 
 in Vehicle Control Systems.
- 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 
.
 
- 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 
.
 
Speakers - One Channel Inoperative
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 
Circuit Testing 
 and 
Wiring Repairs 
 in Wiring Systems.
- Speaker output circuit from amplifier shorted. Test the appropriate speaker
output circuits for a short to ground or short to voltage. Refer to 
Circuit Testing 
 and 
Wiring Repairs 
in Wiring Systems.
 
- Replace the amplifier. Refer to 
Radio Speaker Amplifier Replacement 
.