[Previous][Next]
DTC U0001: Malfunction of CAN communication circuit (Bus off)
 
 
 
 
DIAGNOSTIC FUNCTION
The TCM determines that the system is defective if CAN communication information cannot be sent or received.
 
 
DESCRIPTIONS OF MONITOR METHODS
Bus-off error is detected.
 
 
MONITOR EXECUTION
  • When 1.05 seconds have elapsed after TCM started.
 
 
MONITOR EXECUTION CONDITIONS (OTHER MONITOR AND SENSOR)
Other Monitor (There is no temporary DTC stored in memory for the item monitored below)
  • P0712, P0713: Malfunction of the transmission fluid temperature sensor
  • P0715: Malfunction of primary pulley speed sensor
  • P0720: Malfunction of secondary pulley speed sensor
  • P0730: Incorrect gear ratio
  • P0966, P0967: Malfunction of secondary pressure solenoid valve
  • P0970, P0971: Malfunction of primary pressure solenoid valve
  • P2720, P2721: Malfunction of select pressure solenoid valve
  • P2763, P2764: Malfunction of lock-up solenoid valve
  • P2765: Malfunction of turbine speed sensor
Sensor (The sensor below is determined to be normal)
  • Transmission fluid temperature sensor
  • Primary pulley speed sensor
  • Secondary pulley speed sensor
  • Turbine speed sensor
 
 
LOGIC FLOW CHARTS (Monitor Sequence)
 
 
DTC SET CONDITIONS
Check Conditions
  • Voltage of battery: 10 volts or more.
  • Time after TCM start: More than 1.05 seconds.
Judgment Criteria
  • CAN communication: fail.
 
 
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. Scan tool (M.U.T.-IIISE) CAN bus diagnostics.
Use scan tool (M.U.T.-IIISE) to perform the CAN bus diagnosis.
Is the check result normal?
Go to Step 2.
Repair the CAN bus lines (Refer to GROUP 54C - Diagnosis, CAN Bus Diagnostics Table ).
 
STEP 2. Symptom recheck after erasing diagnostic trouble code.
Is the diagnostic trouble code set?
Replace the TCM.
Intermittent malfunction (Refer to GROUP 00 - How to Cope with Intermittent Malfunctions ).