B1278
DTC B1278 or B1279
Diagnostic Instructions
* Perform the Diagnostic System Check - Vehicle Diagnostic System Check - Vehicle prior to using this diagnostic procedure.
* Review Strategy Based Diagnosis Strategy Based Diagnosis for an overview of the diagnostic approach.
* Diagnostic Procedure Instructions Diagnostic Procedure Instructions provides an overview of each diagnostic category.
DTC Descriptors
DTC B1278 01
-
Left Auxiliary Input Signal Circuit Short to Battery
DTC B1278 02
-
Left Auxiliary Input Signal Circuit Short to Ground
DTC B1279 01
-
Right Auxiliary Input Signal Circuit Short to Battery
DTC B1279 02
-
Right Auxiliary Input Signal Circuit Short to Ground
Diagnostic Fault Information
Circuit/System Description
A remote 3.5 mm auxiliary stereo jack allows playback of audio signals from remote devices (e.g., laptop computer, IPOD, MP3 player, etc.). The auxiliary audio jack has an internal mechanical detection switch. The switch is normally closed, connecting the detection circuit to the audio common circuit. When a device is inserted to the auxiliary audio jack, the switch opens and the multimedia player interface module detects a high voltage on the detection circuit. A serial data message is sent to the radio, the radio will switch to AUX as the audio source. The multimedia player interface module receives the analog audio signals from the connected device and sends the signals to the radio.
Conditions for Running the DTC
* Ignition in RUN or ACC position.
* The system voltage is at least 9.5 V and no more than 15.5 V.
* The multimedia player interface module detects a device has been connected to the auxiliary audio input jack.
Conditions for Setting the DTC
B1278 01, B1279 01
* The multimedia player interface module detects a short to battery on either of the audio signal circuits from the auxiliary audio jack.
* The condition is present for greater than 250 mS.
B1278 02, B1279 02
* The multimedia player interface module detects a short to ground on either of the audio signal circuits from the auxiliary audio jack.
* The condition is present for greater than 250 mS.
Action Taken When the DTC Sets
No or reduced audio is heard from the remote audio device.
Conditions for Clearing the DTC
* The conditions for setting the DTC are no longer present on the auxiliary input signal circuits.
* A history DTC clears after 50 malfunction-free ignition cycles.
Diagnostic Aids
* Playback of an audio device that is connected to the 3.5 mm jack can only be controlled using the controls on the device.
* The volume control on the device may need to be adjusted to ensure sufficient playback volume through the infotainment system.
* This DTC may be stored as a history DTC without affecting the operation of the module.
* If stored only as a history DTC and not retrieved as a current DTC, do not replace the module.
Reference Information
Schematic Reference
Radio/Navigation System Schematics Radio/Navigation System Schematics
Connector End View Reference
Component Connector End Views Sunshade - Left (DH6)
Description and Operation
Radio/Audio System Description and Operation (with Color Display) Radio/Audio System Description and Operation (with Color Display)Radio/Audio System Description and Operation (with Monochrome Display) Radio/Audio System Description and Operation (with Monochrome Display)
Electrical Information Reference
* Circuit Testing Circuit Testing
* Connector Repairs Connector Repairs
* Testing for Intermittent Conditions and Poor Connections Testing for Intermittent Conditions and Poor Connections
* Wiring Repairs Wiring Repairs
Scan Tool Reference
Control Module References Control Module References for scan tool information
Circuit/System Testing
1. Ignition OFF, disconnect the X1 harness connector at the X83 auxiliary audio input.
2. Ignition ON, test for less than 1 V between the terminals listed below and ground:
* Signal terminal 1
* Signal terminal 2
• If greater than the specified value, test the circuit for a short to voltage. If the circuit tests normal, replace the T11 multimedia player interface module.
3. Ignition OFF, test for infinite resistance between the terminals listed below and ground:
* Signal terminal 1
* Signal terminal 2
• If less than the specified value, test the circuit for a short to ground. If the circuit tests normal, replace the T11 multimedia player interface module.
4. If all of the circuits test normal, replace the X83 auxiliary audio input.
Repair Instructions
Perform the Diagnostic Repair Verification Verification Tests after completing the diagnostic procedure.
Control Module References Control Module References multimedia player interface module replacement, setup, and programming