2010 Cadillac CTS Sedan AWD V6-3.6L Page 350
Circuit/System Description
The radio amp control circuit provides varying pulse width modulated (PWM) signals to control overall muting of the amplifier. The PWM signals
are varying duty cycle percentages ranging from 0-100 percent. A low duty cycle unmutes all amplifier channels and a high duty cycle mutes all
amplifier channels. The radio monitors the amp control circuit for faults. When a fault is detected the radio sets the appropriate DTC.
Conditions for Running the DTC
The following are conditions that must be present in order for the radio to enable the diagnostics.
* The radio is in ACCESSORY, RUN, or RAP power mode.
* The system voltage is at least 9 volts and no more than 16 volts.
Conditions for Setting the DTC
The radio detects a fault on the Amp Control circuit 400 ms after radio activates the Remote Enable circuit.
Action Taken When the DTC Sets
Radio sets the DTC and continues to output correct state.
Conditions for Clearing the DTC
* The condition must be corrected.
* A history DTC clears after 100 malfunction-free ignition cycles.
* The radio receives the clear code command from the scan tool.
Reference Information
Schematic Reference
Radio/Navigation System Schematics (See: Accessories and Optional Equipment/Diagrams/Electrical Diagrams/Radio/Navigation System
Schematics)
Connector End View Reference
Component Connector End Views (See: Diagrams/Connector Views)
Electrical Information Reference
* Circuit Testing (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit Testing/Circuit Testing)
* Connector Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Connector Repairs/Connector Repairs)
* Testing for Intermittent Conditions and Poor Connections (See: Testing and Inspection/Component Tests and General Diagnostics/Circuit
Testing/Testing for Intermittent Conditions and Poor Connections)
* Wiring Repairs (See: Testing and Inspection/Component Tests and General Diagnostics/Wiring Repairs/Wiring Repairs)
Circuit/System Verification
Verify the audio system performance by adjusting the fade and balance of the speaker outputs.
Circuit/System Testing
RPO Code UQA
1. Ignition OFF, disconnect the radio X1 harness connector and the X3 amplifier harness connector.
2. Ignition ON, test for less than 1 volt on the radio audio mute signal terminal 37 X1 at the radio.
瀚慖f greater then the specified value, test the circuit for a short to voltage.
3. Test for less than 5 ohms between the radio X1 terminal 37 to the amplifier X3 terminal 11.
瀚慖f greater then specified range, test the circuit for an open/high resistance.
Repair Instructions
Perform the Diagnostic Repair Verification (See: Verification Tests) after completing the diagnostic procedure.
