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)
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

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. CAN Bus Diagnostics Chart.) After repairing the CAN bus line, go to Step 2.
STEP 2. Check whether the DTC is reset.

After 15 seconds with the engine idle status, check that the DTC is reset.

Q. Is DTC No. P1868 set?

YES Replace the transaxle assembly. (Refer to Removal and Replacement.)
NO Intermittent malfunction. How to Cope With Intermittent Malfunctions.)