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DTC U0140-00: Lost Communication with BCM
 
 
caution
  • If DTC U0140-00 is set in the ECM, surely perform CAN bus line diagnosis.
  • Replace ECU after certainly confirming that the communication circuits are normal.
 
 
DTC SET CONDITIONS
Check Conditions
  • More than 2 seconds have passed since the power supply mode of the electric motor switch was ON.
  • 12V battery positive voltage is more than10.0 volts and is less than 16.5 volts.
Judgment Criterion
  • Unable to receive Body Control Module (BCM) through the CAN bus line for 4 seconds.
 
 
COMMENT
Current Trouble
  • Some of the possible causes are a harness or connector damage between the ECM and the BCM on the CAN bus line, a failure in the BCM power supply system, a failure in the BCM, or a failure in the ECM.
Past Trouble
  • Proceed to troubleshoot based on a harness or connector damage on the CAN bus line between the ECM and BCM, and a failure in the BCM power supply system. For diagnostic procedure, refer to how to cope with past malfunctions (Refer to GENERAL INFORMATION, General Information – How to Use Troubleshooting/Inspection Service Points – How to Treat Past Trouble HOW TO TREAT PAST TROUBLE).
noteIf a malfunction occurred in the past, a failure cannot be discovered through the scan tool (M.U.T.-III SE) CAN bus diagnosis even if there might be a problem with the CAN bus. In this case, refer to GENERAL INFORMATION, General Information – How to Use Troubleshooting/Inspection Service Points – How to Cope with Intermittent Malfunctions HOW TO COPE WITH INTERMITTENT MALFUNCTIONS). Furthermore, it is possible to narrow down the areas of the possible failures from the DTCs that are set in the ECUs, which are communicating on the CAN bus (Refer to ELECTRICAL & POWER CONTROL, LAN System – CAN Fundamental – Basic Inspection – Diagnosis and Repair Workflow – Trouble Diagnosis Flow Chart Trouble Diagnosis Flow Chart).
 
 
FAIL-SAFE AND BACKUP FUNCTION
None.
 
 
OBD-II DRIVE CYCLE PATTERN
None.
 
 
TROUBLESHOOTING HINTS (The most likely causes for this code to be set are:)
  • CAN line harness damage or connector damage.
  • BCM failed.
  • ECM failed.
 
 
DIAGNOSIS
Required Special Tools:
  • MB992744: Vehicle communication interface-Lite (V.C.I.-Lite)
  • MB992745: V.C.I.-Lite main harness A
  • MB992747: V.C.I.-Lite USB cable short
  • MB992748: V.C.I.-Lite USB cable long
1.STEP 1. Using scan tool (M.U.T.-IIISE), diagnostic CAN bus line.
Use scan tool (M.U.T.-III SE) to perform CAN bus line diagnostic (Refer to ELECTRICAL & POWER CONTROL, LAN System – CAN Fundamental – Basic Inspection – Diagnosis and Repair Workflow – Trouble Diagnosis Flow Chart Trouble Diagnosis Flow Chart).
Q: Is the CAN bus line normal?
Repair CAN bus line (Refer to ELECTRICAL & POWER CONTROL, LAN System – CAN – DTC/Circuit Diagnosis – Malfunction Area Chart – Drivetrain CAN Communication Circuit Drivetrain CAN Communication Circuit). Then
 
2.STEP 2. Using scan tool (M.U.T.-III SE), read the other system DTC.
Use scan tool (M.U.T.-III SE) to check and see if a DTC is set in the BCM.
Q: Is any DTC set in the BCM?
Perform troubleshooting of BCM system (Refer to ELECTRICAL AND POWER CONTROL, Body Control System – ECU Diagnosis Information – BCM – DTC Index DTC Index).
 
3.STEP 3. Using scan tool (M.U.T.-III SE), read the other system DTC.
Use scan tool (M.U.T.-III SE) to check and see if a DTC of BCM CAN timeout is set in the PHEV-ECU (Refer to ELECTRIC POWER TRAIN, PHEV-ECU – Troubleshooting – Diagnosis Function DIAGNOSTIC FUNCTION). And check whether the DTC of CAN communication system (BCM) is set in the chassis control module (Refer to CRUISE CONTROL DRIVER ASSISTANCE, Driver Assistance System – Chassis Control – Basic Inspection – Diagnosis and Repair work Flow – Work Flow Work Flow).
Q: Is the DTC of BCM CAN timeout set in the PHEV-ECU? Or Is the DTC of CAN communication system (BCM) set in the chassis control module?
 
4.STEP 4. Using scan tool (M.U.T.-III SE), DTC recheck after erasing DTC.
After erasing the DTC, check again to see if the DTC is set again.
(1) Use scan tool (M.U.T.-III SE) to erase the DTC.
(2) Turn OFF the power supply mode of the electric motor switch.
(3) Turn ON the power supply mode of the electric motor switch.
(4) Use scan tool (M.U.T.-III SE) to recheck the DTC.
Q: Is DTC U0140-00 set?
Replace the BCM (Refer to ELECTRICAL & POWER CONTROL, Body Control System – Removal and Installation – BCM Removal and Installation). Then
Intermittent malfunction in CAN bus line between ECM and BCM (Refer to GENERAL INFORMATION, General Information – How to Use Troubleshooting/Inspection Service Points – How to Cope with Intermittent Malfunctions HOW TO COPE WITH INTERMITTENT MALFUNCTIONS).
 
5.STEP 5. Using scan tool (M.U.T.-III SE), DTC recheck after erasing DTC.
After erasing the DTC, check again to see if the DTC is set again.
(1) Use scan tool (M.U.T.-III SE) to erase the DTC.
(2) Turn OFF the power supply mode of the electric motor switch.
(3) Turn ON the power supply mode of the electric motor switch.
(4) Use scan tool (M.U.T.-III SE) to recheck the DTC.
Q: Is DTC U0140-00 set?
Replace the ECM (Refer to ENGINE CONTROL MODULE (ECM) REMOVAL AND INSTALLATION). Then
Intermittent malfunction in CAN bus line between ECM and BCM (Refer to GENERAL INFORMATION, General Information – How to Use Troubleshooting/Inspection Service Points – How to Cope with Intermittent Malfunctions HOW TO COPE WITH INTERMITTENT MALFUNCTIONS).
 
6.STEP 6. Using scan tool (M.U.T.-III SE), DTC recheck after erasing DTC.
After erasing the DTC, check again to see if the DTC is set again.
(1) Use scan tool (M.U.T.-III SE) to erase the DTC.
(2) Turn OFF the power supply mode of the electric motor switch.
(3) Turn ON the power supply mode of the electric motor switch.
(4) Use scan tool (M.U.T.-III SE) to recheck the DTC.
Q: Is DTC U0140-00 set?
Retry the troubleshooting
The inspection is complete.