Pinpoint Test AB: DTC U0140 Or DTC U0140:00
Information and Entertainment System
Pinpoint Tests
Pinpoint Test AB: DTC U0140 Or DTC U0140:00
Normal Operation
Several audio system modules receive network messages from the Smart Junction Box (SJB) via the Medium Speed Controller Area Network (MS-CAN). The following information is included in the messages:
- Ignition switch position
- Illumination dimmer control
- Accessory delay status
As more than one module receives each of these messages, all modules receiving that particular message should exhibit a symptom if the message is missing.
- DTC U0140 (Lost Communication With Body Control Module (GEM)) - set by the Front Display Interface Module (FDIM) when it is missing network messages from the SJB for greater than 5 seconds with the ignition in RUN.
- DTC U0140:00 (Lost Communication With Body Control Module: No Sub Type Information) - set by the Audio Control Module (ACM), the Accessory Protocol Interface Module (APIM) (V2 only), the audio Digital Signal Processing (DSP) module, or the Front Controls Interface Module (FCIM) when network messages are missing from the SJB for greater than 5 seconds with the ignition in RUN.
This pinpoint test is intended to diagnose the following:
- Communication network concern
- Audio system concern
- SJB
PINPOINT TEST AB: DTC U0140 OR DTC U0140:00
-------------------------------------------------
AB1 CHECK FOR LOST COMMUNICATION DTCs
- Ignition ON.
- Clear continuous DTCs from all modules.
- Ignition OFF.
- Ignition ON.
- Wait at least 10 seconds.
- Retrieve all continuous DTCs from all modules.
- Is DTC U0140 or U0140:00 set in any audio system module?
Yes
GO to AB2.
No
The system is operating correctly at this time. The DTC may have been set due to an intermittent fault in the network wiring.
-------------------------------------------------
AB2 CHECK FOR BATTERY VOLTAGE OUT-OF-RANGE DTCs
- Carry out the self-test for the following modules:
- ACM
- APIM
- Audio DSP module
- FCIM
- FDIM
- SJB
- Is DTC B1317, B1318, U3003:16, or U3003:17 recorded in any module?
Yes
For an audio system module, REFER to DTC Charts. [1][2]Diagnostic Trouble Code Descriptions
For the SJB, REFER to Body Control Systems.
No
GO to AB3.
-------------------------------------------------
AB3 CHECK FOR DTC U0140 OR U0140:00 SET IN MULTIPLE MODULES
- Review the recorded results from the self-test.
- Is DTC U0140 or DTC U0140:00 set in more than one audio system module?
Yes
GO to AB4.
No
If there is an observable symptom, GO to Symptom Chart - General Audio System to diagnose the observed symptom. Symptom Chart - General Audio System
If there is no observable symptom, CHECK the MS-CAN wiring between the SJB and the module in question for an intermittent fault.
-------------------------------------------------
AB4 CHECK FOR CORRECT SJB OPERATION
- Ignition OFF.
- Disconnect all the SJB connectors.
- Check for:
- corrosion
- damaged pins
- pushed-out pins
- Connect all the SJB connectors and make sure they seat correctly.
- Operate the system and determine if the concern is still present.
- Is the concern still present?
Yes
INSTALL a new SJB. CLEAR all continuous DTCs. REPEAT the self-test.
No
The system is operating correctly at this time. The concern may have been caused by a loose or corroded connector. CLEAR all continuous DTCs. REPEAT the self-test.
-------------------------------------------------