Diagnostic Instructions
Diagnostic Fault Information
Circuit
| Short to Ground
| Open/High Resistance
| Short to Voltage
| Signal Performance
|
Amplifier Battery Positive Voltage
| 1
| 1
| --
| --
|
Amplifier Control
| B1287 02
| B1287 04
| B1287 01
| --
|
Amplifier Ground
| --
| 1
| --
| --
|
Antenna 14V switched Supply Voltage
| 1
| 1
| --
| --
|
Left Front Low Level Audio Signal (+)/Left Front Speaker Signal (+)
| B1025 02*
| B1025 04*
| B1025 01*
| --
|
Left Front Low Level Audio Signal (-)/Left Front Speaker Signal (-)
| B1025 02*
| B1025 04*
| B1025 01*
| --
|
Right Front Low Level Audio Signal (+)/Right Front Speaker Signal (+)
| B1035 02*
| B1035 04*
| B1035 01*
| --
|
Right Front Low Level Audio Signal (-)/Right Front Speaker Signal (-)
| B1035 02*
| B1035 04*
| B1035 01*
| --
|
Left Rear Low Level Audio Signal (+)/Left Rear Speaker Signal (+)
| B1045 02*
| B1045 04*
| B1045 01*
| --
|
Left Rear Low Level Audio Signal (-)/Left Rear Speaker Signal (-)
| B1045 02*
| B1045 04*
| B1045 01*
| --
|
Right Rear Low Level Audio Signal (+)/Right Rear Speaker Signal (+)
| B1055 02*
| B1055 04*
| B1055 01*
| --
|
Right Rear Low Level Audio Signal (-)/Right Rear Speaker Signal (-)
| B1055 02*
| B1055 04*
| B1055 01*
| --
|
Front Center Speaker (+)
| B1065 02*
| B1065 04*
| B1065 01*
| --
|
Front Center Speaker (-)
| B1065 02*
| B1065 04*
| B1065 01*
| --
|
Subwoofer Audio Signal (+)
| B1075 02*
| B1075 04*
| B1075 01*
| --
|
Subwoofer Audio Signal (-)
| B1075 02*
| B1075 04*
| B1075 01*
| --
|
1. Amplifier inoperative/no sound from speakers
* Speaker output DTCs available when equipped with amplifier UQA only
|
Circuit/System Description
Each of the audio output channel circuits (+) and (-), at the radio and at the amplifier have a DC bias voltage that is one half of the battery voltage. When using a DMM, each of the audio output channel circuits will measure approximately 6.5V DC. The
audio being played on the system is produced by a varying AC voltage that is centered around the DC bias voltage on the same circuit. The AC voltage is what causes the speaker cone to move and produce sound. This voltage will vary depending on what type of audio
is being listened to, talk or music, and type of music, as well as the volume setting of the system. Low volume and talk settings will measure around 1V AC and less, where constant music may measure 3V AC and slightly higher.
Amplifier UQA
The radio provides left and right audio signals to the amplifier. The amplifier is supplied battery voltage from a dedicated fuse in the rear fuse block. The amplifier communicates with the vehicle via serial data, which controls the power state of the
amplifier and allows the amplifier to set DTCs. Balance/fade and muting functions are all performed by the amplifier based on serial data messages.
Amplifier UQ3
The radio provides four channels of audio signals to the amplifier- left front, left rear, right front and right rear. The amplifier is supplied battery voltage from a dedicated fuse in the rear fuse block. The amplifier power state is controlled by a
remote enable signal via the antenna 14V switched supply circuit, which also provides power to the antenna module. Amplifier muting functions are controlled by a dedicated pulse width modulated signal from the radio via the amp control circuit. The amplifier
provides eight audio output channels to the speakers. This amplifier does not communicate on the serial data bus and cannot set DTCs.
Diagnostic Aids
| • | Improper speaker mounting or loose trim may cause an audible buzz or distortion. Inspect the appropriate speaker and the surrounding interior trim for proper and secure mounting. If the speaker or surrounding interior trim is found to be loose or
improperly secured, correctly secure the item. |
| • | When equipped with an amplifier, it is possible for some individual circuit faults to affect more than one speakers operation. Perform diagnostic tests in the sequence listed to avoid misdiagnosis. |
Reference Information
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
Circuit/System Verification
Radio ON, verify clear audio is heard from each audio speaker.
| ⇒ | If audio is inoperative from all speakers, refer to Amplifier Circuit Malfunction. |
| ⇒ | If audio is inoperative from one or more, but not all, speakers or the audio emitted from the speakers is not clear, refer to Speaker
Circuit Malfunction |
Circuit/System Testing
Amplifier Circuit Malfunction with UQ3
- Ignition OFF, disconnect the X1 harness connector at the amplifier.
- Test for less than 10 ohms of resistance between the ground circuit terminal 2 and ground.
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. |
- Ignition ON, verify a test lamp illuminates between the B+ circuit terminal 1 and ground.
| ⇒ | If the test lamp does not illuminate, test the B+ circuit for a short to ground or an open/high resistance. If the circuit tests normal and the circuit fuse is open, replace the amplifier. |
- Disconnect the X3 harness connector at the amplifier.
- Radio ON, test for 0.5-1.0 volts between the signal circuit terminal 5 and ground.
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio. |
| ⇒ | If less than the specified range, test the signal circuit for a short to ground
or an open/high resistance. If the circuit tests normal, replace the radio. |
- Verify a test lamp illuminates between the signal circuit terminal 6 and ground.
| ⇒ | If the test lamp does not illuminate, test the signal circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio. |
- If all circuits test normal, replace the amplifier.
Speaker Circuit Malfunction with UQ3
- Ignition OFF, disconnect the X3 harness connector at the amplifier.
- Radio ON, test for 5.0-7.5 volts between the appropriate signal circuit terminal listed below and ground.
| • | Left front low level audio signal (+) -terminal 1 |
| • | Left front low level audio signal (-) -terminal 2 |
| • | Right front low level audio signal (+) -terminal 10 |
| • | Right front low level audio signal (-) -terminal 9 |
| • | Left rear low level audio signal (+) -terminal 4 |
| • | Left rear low level audio signal (-) -terminal 3 |
| • | Right rear low level audio signal (+) -terminal 11 |
| • | Right rear low level audio signal (-) -terminal 12 |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the radio. |
| ⇒ | If less than the specified range, test the signal circuit for a short to ground
or an open/high resistance. If the circuit tests normal, replace the radio. |
- Ignition OFF, disconnect the X1 and X2 harness connectors at the amplifier.
- Ignition ON, test for less than 1 volt between each of the signal circuit terminals listed below and ground.
| • | Front center speaker output (+) -terminal 3 X1 |
| • | Front center speaker output (-)-terminal 4 X1 |
| • | Subwoofer speaker output (+) -terminal 8 X1 |
| • | Subwoofer speaker output (-)-terminal 7 X1 |
| • | Left front tweeter speaker output (+)- terminal 1 X2 |
| • | Left front tweeter speaker output (-)-terminal 2 X2 |
| • | Right front tweeter speaker output (+)- terminal 3 X2 |
| • | Right front tweeter speaker output (-) -terminal 4 X2 |
| • | Left front speaker output (+)- terminal 15 X2 |
| • | Left front speaker output (-)-terminal 16 X2 |
| • | Right front speaker output (+)- terminal 13 X2 |
| • | Right front speaker output (-) -terminal 14 X2 |
| • | Left rear speaker output (+) -terminal 6 X2 |
| • | Left rear speaker output (-) -terminal 5 X2 |
| • | Right rear speaker output (+)- terminal 8 X2 |
| • | Right rear speaker output (-)- terminal 7 X2 |
| ⇒ | If greater than the specified range, test both signal circuits of the affected speaker for a short to voltage. |
- Ignition OFF, test for infinite resistance between each of the signal circuit terminals listed below and ground.
| • | Front center speaker output (+) -terminal 3 X1 |
| • | Front center speaker output (-)-terminal 4 X1 |
| • | Subwoofer speaker output (+) -terminal 8 X1 |
| • | Subwoofer speaker output (-)-terminal 7 X1 |
| • | Left front tweeter speaker output (+)- terminal 1 X2 |
| • | Left front tweeter speaker output (-)-terminal 2 X2 |
| • | Right front tweeter speaker output (+)- terminal 3 X2 |
| • | Right front tweeter speaker output (-) -terminal 4 X2 |
| • | Left front speaker output (+)- terminal 15 X2 |
| • | Left front speaker output (-)-terminal 16 X2 |
| • | Right front speaker output (+)- terminal 13 X2 |
| • | Right front speaker output (-) -terminal 14 X2 |
| • | Left rear speaker output (+) -terminal 6 X2 |
| • | Left rear speaker output (-) -terminal 5 X2 |
| • | Right rear speaker output (+)- terminal 8 X2 |
| • | Right rear speaker output (-)- terminal 7 X2 |
| ⇒ | If less than the specified range, test both signal circuits of the affected speaker for a short to ground. |
- Reconnect all harness connectors at the amplifier. Disconnect the harness connector at the appropriate speaker.
- Radio ON, test for 5.0-7.5 volts between each of the appropriate signal circuit terminals listed below and ground.
| • | Front tweeter speakers - terminals A and B |
| • | Center IP speaker- terminals A and B |
| • | Door speakers - terminals A and B |
| • | Subwoofer speaker - terminals A and B |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the audio amplifier. |
| ⇒ | If less than the specified range, test the signal circuit for a short
to ground or an open/high resistance. If the circuit tests normal, replace the audio amplifier. |
- If all circuits test normal, replace the inoperative speaker.
Speaker Circuit Malfunction with UQA
- Ignition OFF, disconnect the X3 harness connector at the audio amplifier.
- Radio ON, test for 5.0-7.5 volts between the appropriate signal circuit terminal listed below and ground.
| • | Left low level audio signal (+) -terminal 11 |
| • | Left low level audio signal (-) -terminal 12 |
| • | Right low level audio signal (+) -terminal 3 |
| • | Right low level audio signal (-) -terminal 4 |
| ⇒ | If greater than the specified range, test the appropriate signal circuit for a short to voltage. If the circuit tests normal, replace the radio. |
| ⇒ | If less than the specified range, test the appropriate signal circuit
for a short to ground or an open/high resistance. If the circuit tests normal, replace the radio. |
- Ignition OFF, disconnect the X1 and X2 harness connectors at the amplifier.
- Ignition ON, test for less than 1 volt between each of the signal circuit terminals listed below and ground.
| • | Subwoofer speaker output (+)- terminal 1 X1 |
| • | Subwoofer speaker output (-) -terminal 2 X1 |
| • | Left front speaker output (+)- terminal 4 X2 |
| • | Left front speaker output (-)-terminal 5 X2 |
| • | Right front speaker output (+)- terminal 7 X2 |
| • | Right front speaker output (-) -terminal 6 X2 |
| • | Left rear speaker output (+) -terminal 15 X2 |
| • | Left rear speaker output (-) -terminal 14 X2 |
| • | Right rear speaker output (+)- terminal 16 X2 |
| • | Right rear speaker output (-)- terminal 8 X2 |
| • | Front center speaker output (+) -terminal 13 X2 |
| • | Front center speaker output (-)-terminal 12 X2 |
| ⇒ | If greater than the specified range, test both signal circuits of the affected speaker for a short to voltage. |
- Ignition OFF, test for infinite resistance between each of the signal circuit terminals listed below and ground.
| • | Subwoofer speaker output (+)- terminal 1 X1 |
| • | Subwoofer speaker output (-) -terminal 2 X1 |
| • | Left front speaker output (+)- terminal 4 X2 |
| • | Left front speaker output (-)-terminal 5 X2 |
| • | Right front speaker output (+)- terminal 7 X2 |
| • | Right front speaker output (-) -terminal 6 X2 |
| • | Left rear speaker output (+) -terminal 15 X2 |
| • | Left rear speaker output (-) -terminal 14 X2 |
| • | Right rear speaker output (+)- terminal 16 X2 |
| • | Right rear speaker output (-)- terminal 8 X2 |
| • | Front center speaker output (+) -terminal 13 X2 |
| • | Front center speaker output (-)-terminal 12 X2 |
| ⇒ | If less than the specified range, test both signal circuits of the affected speaker for a short to ground. |
- Reconnect all harness connectors at the amplifier. Disconnect the harness connector at the appropriate speaker.
- Radio ON, test for 5.0-7.5 volts between each of the appropriate signal circuit terminals listed below and ground.
| • | Front tweeter speakers - terminals A and B |
| • | Center IP speaker- terminals A and B |
| • | Door speakers - terminals A and B |
| • | Subwoofer speaker - terminals A and B |
| ⇒ | If greater than the specified range, test the signal circuit for a short to voltage. If the circuit tests normal, replace the audio amplifier. |
| ⇒ | If less than the specified range, test the signal circuit for a short
to ground or an open/high resistance. If the circuit tests normal, replace the audio amplifier. |
- If all circuits test normal, replace the inoperative speaker.
Repair Instructions
Perform the
Diagnostic Repair Verification after completing the diagnostic procedure.
