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DTC U0001: Malfunction of CAN Communication Circuit
 
 
 
 
DIAGNOSTIC FUNCTION
The TCM determines that the system is defective if CAN communication information cannot be sent or received.
 
 
DESCRIPTIONS OF MONITOR METHODS
  • TCM cannot receive the periodic communication data.
 
 
MONITOR EXECUTION
  • Continuous
 
 
MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
  • Not applicable
Sensor (The sensor below is determined to be normal)
  • Not applicable
 
 
LOGIC FLOW CHARTS (Monitor Sequence)
 
 
DTC SET CONDITIONS
Check Conditions
  • Time after TCM start: more than 0.7 seconds.
  • Voltage of battery: 10 volts or more
  • Voltage of battery: 16.5 volts or less
Judgment Criteria
  • CAN communication: fail (Bus-off error is detected)
 
 
OBD-II DRIVE CYCLE PATTERN
Ignition switch: ON (start the engine and keep it for 10 seconds or more)
 
 
PROBABLE CAUSES
  • Malfunction of the CAN bus line
 
 
DIAGNOSIS
STEP 1. M.U.T.-III CAN bus diagnostics
Use M.U.T.-III to perform the CAN bus diagnosis.
Is the check result normal?
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C - Troubleshooting, Diagnostic Trouble Code Chart ).
 
STEP 2. Symptom recheck after erasing diagnostic trouble code
Is the diagnostic trouble code stored?
Replace the TCM.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunctions .).