B1449

DTC B1449

Diagnostic Instructions

* Perform the Diagnostic System Check - Vehicle (Initial Inspection and Diagnostic Overview) prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis (Initial Inspection and Diagnostic Overview) for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions (Initial Inspection and Diagnostic Overview) provides an overview of each diagnostic category.

DTC Descriptors
DTC B1449 03
- Remote Device Voltage Below Threshold

DTC B1449 07
- Remote Device Voltage Above Threshold

Diagnostic Fault Information





Circuit/System Description

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.

Conditions for Running the DTC

* Ignition ON.
* Battery voltage must be between 9-16 volts.

Conditions for Setting the DTC

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.

Action Taken When the DTC Sets

The rear audio/HVAC module sets the DTC and the infrared module will be disabled.

Conditions for Clearing the DTC

* The condition responsible for setting the DTC no longer exists.
* A history DTC will clear once 100 consecutive malfunction-free ignition cycles have occurred.

Reference Information
Schematic Reference

Radio/Navigation System Schematics (Radio/Navigation System Schematics)
Connector End View Reference

Component Connector End Views (Connector Views)
Description and Operation

Video Entertainment System Description and Operation (Non-Headrest DVD Systems) (Video Entertainment System Description and Operation (Non-Headrest DVD Systems))
Electrical Information Reference

* Circuit Testing (Component Tests and General Diagnostics)
* Connector Repairs (Component Tests and General Diagnostics)
* Testing for Intermittent Conditions and Poor Connections (Component Tests and General Diagnostics)
* Wiring Repairs (Component Tests and General Diagnostics)

Scan Tool Reference

Control Module References (Programming and Relearning) for scan tool information

Circuit/System Testing

1. Ignition OFF, disconnect the harness connector at the infrared module.
2. Ignition OFF, test for less than 5.0 ohms between the ground circuit terminal 12 and ground.

• If greater than the specified range, test the ground circuit for an open/high resistance.

3. Ignition ON, rear audio ON, test for 10.0-11.0 volts between the supply voltage circuit terminal 4 and ground.

• 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.

4. If all circuits test normal, replace the infrared module.

Repair Instructions

Perform the Diagnostic Repair Verification (Verification Tests) after completing the diagnostic procedure.

* Audio System Transceiver Module Replacement (U42) (Audio System Transceiver Module Replacement (U42))Audio System Transceiver Module Replacement (U42/C3U) (Audio System Transceiver Module Replacement (U42/C3U))
* Control Module References (Programming and Relearning) for Rear Audio/HVAC Module replacement, setup, and programming