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DTC U1944: LIN (EV-CAN B/U) Checksum Error
 
 
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
  • When the signal sent from the PHEV-ECU is abnormal
 
 
 
FAIL-SAFE AND BACKUP FUNCTION
  • Not available
 
 
PROBABLE CAUSES
  • 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.
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 ). Then go to Step 2.
Intermittent malfunction in LIN bus line between battery management unit (BMU) and PHEV-ECU (Refer to GROUP 00 - How to Use Troubleshooting/Inspection Service Points - How to Cope with Intermittent Malfunctions ).
 
STEP 2. 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 PHEV-ECU (Refer to GROUP 54Da - PHEV-ECU ).
The procedure is complete.