| • | Perform the Diagnostic System Check - Vehicle prior to using this diagnostic procedure. | 
| • | Review Strategy Based Diagnosis for an overview of the diagnostic approach. | 
| • | Diagnostic Procedure Instructions provides an overview of each diagnostic category. | 
Circuit  | Short to Ground  | Open/High Resistance  | Short to Voltage  | Signal Performance  | 
|---|---|---|---|---|
Infrared Module Voltage Signal  | B1449 03  | B1449 03  | B1449 07  | --  | 
The infrared module is supplied with 10.5 volts from the rear audio/HVAC module when the rear audio system is active. The infrared module is permanently grounded at G300.
| • | Ignition ON. | 
| • | Battery voltage must be between 9-16 volts. | 
The DTC will set when the rear audio/HVAC module detects a short to voltage, short to ground, or an open/high resistance in the infrared module voltage signal circuit.
The rear audio/HVAC module sets the DTC and the infrared module will be disabled.
| • | The condition responsible for setting the DTC no longer exists. | 
| • | A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred. | 
Radio/Navigation System Schematics
Video Entertainment System Description and Operation
Control Module References for scan tool information
| ⇒ | If greater than the specified range, test the ground circuit for an open/high resistance. | 
| ⇒ | If less than the specified range, test the voltage supply circuit for a short to ground or an open/high resistance. If the circuit tests normal, replace the rear audio/HVAC module. | 
| ⇒ | If greater than the specified range, test the voltage supply circuit for a short to voltage. If the circuit tests normal, replace the rear audio/HVAC module. | 
Perform the Diagnostic Repair Verification after completing the diagnostic procedure.
| • | Control Module References for Rear Audio/HVAC Module replacement, setup, and programming |