P1868

DTC P1868: High side 2 system (Short to power supply)

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 high side 2 circuit is normal.

DESCRIPTIONS OF MONITOR METHODS
The high side 2 circuit is determined to be short to power supply.

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)
^ P0776: Clutch cooling flow solenoid system (Drive current range out)
^ P0777: Clutch cooling flow solenoid system (Stuck)
^ P0964: Clutch cooling flow solenoid system (Open circuit)
^ P0965: Clutch cooling flow solenoid system (Overvoltage)
^ P0966: Clutch cooling flow solenoid system (Short to ground)
^ P0967: Clutch cooling flow solenoid system (Short to power supply)
^ P2718: Clutch/shift pressure solenoid 1 system (Open circuit)
^ P2719: Clutch/shift pressure solenoid 1 system (Overcurrent)
^ P2720: Clutch/shift pressure solenoid 1 system (Short to ground)
^ P2721: Clutch/shift pressure solenoid 1 system (Short to power supply)
^ P2733: Clutch/shift switching solenoid 1, spool stuck
^ P2736: Clutch/shift switching solenoid 1 system (Open circuit)
^ P2738: Clutch/shift switching solenoid 1 system (Short to ground)
^ P2739: Clutch/shift switching solenoid 1 system (Short to power supply)
^ P181B: Clutch 1 (Pressure low range out) P181C: Clutch 1 (Pressure high range out)
^ P1859: Disengagement too late with clutch 1

Sensor (The sensor below is determined to be normal)
^ Clutch cooling flow solenoid Clutch/shift pressure solenoid 1 Clutch/shift switching solenoid 1

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.
^ High side 2 switch: OFF.

JUDGMENT CRITERIA
^ FET (Field Effect Transistor): Can't be switched off. (12 seconds)

OBD-II DRIVE CYCLE PATTERN
The FET switch remains OFF for 12 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. P1868 set?
YES: Replace the TC-SST assembly.
NO: Intermittent malfunction.