P181B

DTC P181B: Clutch 1 (Pressure low range out)

CAUTION:
^ 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.

DIAGNOSTIC FUNCTION
TC-SST-ECU checks that the clutch 1 pressure is normal.

DESCRIPTIONS OF MONITOR METHODS
The pressure of the clutch 1 is too low.

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)
^ P1836: Shift fork 1 malfunction
^ P183D: Shift fork 2 malfunction

Sensor (The sensor below is determined to be normal)
^ Clutch 1 pressure sensor

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.
^ Engine speed: 500 r/min or more.
^ Time since above engine condition: 400 millisecond or more.
^ Clutch 1 (odd) state: Slip or engaged.
^ Clutch/shift pressure solenoid 1: Not OFF or not in valve cleaning mode.

JUDGMENT CRITERIA
Calculated pressure: 2,000 mbar or more. (5 seconds)

OBD-II DRIVE CYCLE PATTERN
The calculated pressure remains 2,000 mbar or less for 5 seconds.

PROBABLE CAUSES
^ Malfunction of TC-SST-ECU

DIAGNOSTIC PROCEDURE

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.

Q: Is DTC No. P181B set?
YES: Replace the TC-SST assembly.
NO: Intermittent malfunction.