[Previous][Next]
DTC U1945: LIN (EV-CAN B/U) No Bus Activity
 
 
caution
  • If there is any problem in the CAN bus lines, an incorrect DTC may be set. Prior to this diagnosis, diagnose the CAN bus lines (Refer to GROUP 54C - CAN Bus Diagnostics Table ).
  • Whenever ECU is replaced, ensure that the CAN bus lines are normal.
 
 
TROUBLE JUDGMENT
Check Condition
  • The power supply mode of the electric motor switch is ON, or the main drive lithium-ion battery starts to be charged.
Judgment Criterion
  • The communication is not available for a certain period, or a short circuit to ground of EV-LIN bus
 
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • Not available
 
 
PROBABLE CAUSES
  • The harnesses and connectors are failed.
  • The PHEV-ECU is failed.
  • The battery management unit (BMU) is failed.
 
 
 
 
DIAGNOSIS
STEP 1. Using scan tool (M.U.T.-IIISE), check whether the DTC is set.
Check whether the DTC is set in the PHEV-ECU.
Is the DTC set?
Perform the troubleshooting of the PHEV-ECU (Refer to GROUP 54Da - Diagnostic Trouble Code Chart ).
Go to Step 2.
 
STEP 2. Check of short to ground circuit, open circuit and damage circuit in the LIN1 line between battery management unit (BMU) connector and PHEV-ECU connector.
Is the check result normal?
Go to Step 3.
Repair the connector or wiring harness.
 
STEP 3. Using scan tool (M.U.T.-IIISE), check whether the DTC is set again.
Recheck the DTC.
(1) 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) Check the DTC.
Is the DTC set?
Replace the battery management unit (BMU) (Refer to ).
The trouble can be an intermittent malfunction (Refer to GROUP 00, How to Cope with Intermittent Malfunction ).