Twin Clutch-Sportronic Shift Transmission (TC-SST)
DTC U0001: Bus-offCAUTION
^ If there is any problem in the CAN bus lines, an incorrect diagnostic trouble code may be set. Prior to this diagnosis, diagnose the CAN bus lines.
^ Whenever the ECU is replaced, ensure that the CAN bus lines are normal.
DESCRIPTIONS OF MONITOR METHODS
TC-SST-ECU ceases communication (bus-off).
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)
^ P0841: Clutch 1 pressure sensor system (Poor performance)
^ P0842: Clutch 1 pressure sensor system (Output low range out)
^ P0843: Clutch 1 pressure sensor system (Output high range out)
^ P0846: Clutch 2 pressure sensor system (Poor performance)
^ P0847: Clutch 2 pressure sensor system (Output low range out)
^ P0848: Clutch 2 pressure sensor system (Output high range out)
^ P185D: Clutch open not possible
^ U0100: Engine time-out error
^ P1803: Shift lever system (CAN or LIN time-out error)
^ P1870: Engine torque signal abnormality
^ P1871: APS system (Signal abnormality)
^ P1872: Between shift lever and TC-SST system (Q-A function abnormality)
Sensor (The sensor below is determined to be normal)
^ Clutch 1 pressure sensor
^ Clutch 2 pressure sensor
^ APS
^ Shift lever-ECU
LOGIC FLOW CHARTS (Monitor Sequence)
DTC SET CONDITIONS
Check Conditions
^ Voltage of battery: 8 V or more.
^ Voltage of battery: 16.5 V or less.
^ Time after TC-SST-ECU start: 5 seconds or more.
JUDGMENT CRITERIA
^ CAN communication: Error. (60 millisecond)
OBD-II DRIVE CYCLE PATTERN
The CAN communication remains normal for 60 milliseconds.
PROBABLE CAUSES
^ The CAN bus line is defective.
^ Malfunction of TC-SST-ECU
DIAGNOSTIC PROCEDURE
Required Special Tools:
^ MB991958: Scan Tool (M.U.T.-III Sub Assembly)
^ MB991824: Vehicle Communication Interface (V.C.I.)
^ MB991827: M.U.T.-III USB Cable
^ MB991910: M.U.T.-III Main Harness A
STEP 1. Scan tool CAN bus diagnostics
Using scan tool MB991958, diagnose the CAN bus lines.
Q: Is the check result normal?
YES: Go to Step 2.
NO: Repair the CAN bus lines. After repairing the CAN bus line, go to Step 2.
STEP 2. Check whether the DTC is reset.
30 seconds after turning ON the ignition switch, check that the DTC is reset.
Q: Is DTC No. U0001 set?
YES: Replace the mechatronic assembly.
NO: Intermittent malfunction.