DTC P181F: Clutch 2 (Pressure high 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 2 pressure is normal.

DESCRIPTIONS OF MONITOR METHODS

The pressure of the clutch 2 is too high.

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)

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)
P1844: Shift fork 3 malfunction
P184B: Shift fork 4 malfunction

Sensor (The sensor below is determined to be normal)

Clutch 2 pressure sensor

LOGIC FLOW CHARTS (Monitor Sequence) <Target clutch 2 (even) pressure: 3,000 hPa or more>

DTC SET CONDITIONS <TARGET CLUTCH 2 (EVEN) PRESSURE: 3,000 HPA OR MORE>

Check Conditions

Engine speed: 650 r/min or more.
Time since above engine condition: 1.5 seconds or more.
Clutch 2 (even) state: Slip or engaged.
Target clutch 2 (even) pressure: 3,000 hPa or more.

JUDGMENT CRITERIA

Calculated pressure: -5,000 hPa or less. (Time required^*)

*: Time required
The time required for the "Rationality-high" monitor depends on the transmission fluid temperature, the shift lever position.

Shift lever position	Transmission fluid temperature	Time required
"D → N" or "R → N" or "R → P"	>= -10 °C (14 °F)	1,220 msec
"D → N" or "R → N" or "R → P"	< -10 °C (14 °F)	2,220 msec
"N" or "P"	All range	220 msec
"R" or "D" or manual mode	<= -10 °C (14 °F)	3,220 msec
"R" or "D" or manual mode	> -10 °C (14 °F)	2,220 msec

Example of the time required

OBD-II DRIVE CYCLE PATTERN <TARGET CLUTCH 2 (EVEN) PRESSURE: 3,000 HPA OR MORE>

The calculated pressure remains -5,000 hPa or more for time required^*.
*: Time required
The time required for the "Rationality-high" monitor depends on the transmission fluid temperature, the shift lever position.

Shift lever position	Transmission fluid temperature	Time required
"D → N" or "R → N" or "R → P"	>= -10 °C (14 °F)	1,220 msec
"D → N" or "R → N" or "R → P"	< -10 °C (14 °F)	2,220 msec
"N" or "P"	All range	220 msec
"R" or "D" or manual mode	<= -10 °C (14 °F)	3,220 msec
"R" or "D" or manual mode	> -10 °C (14 °F)	2,220 msec

Example of the time required

LOGIC FLOW CHARTS (Monitor Sequence) <Target clutch 2 (even) pressure: 1,400 hPa or more to 3,000 hPa or less>

DTC SET CONDITIONS <TARGET CLUTCH 2 (EVEN) PRESSURE: 1,400 HPA OR MORE TO 3,000 HPA OR LESS>

Check Conditions

Engine speed: 650 r/min or more.
Time since above engine condition: 1.5 seconds or more.
Clutch 2 (even) state: Slip or engaged.
Target clutch 2 (even) pressure: 1,400 hPa or more.

JUDGMENT CRITERIA

Calculated pressure: -2,000 hPa or less. (Time required^*)

*: Time required
The time required for the "Rationality-high" monitor depends on the transmission fluid temperature, the shift lever position.

Shift lever position	Transmission fluid temperature	Time required
"D → N" or "R → N" or "R → P"	>= -10 °C (14 °F)	1,220 msec
"D → N" or "R → N" or "R → P"	< -10 °C (14 °F)	2,220 msec
"N" or "P"	All range	220 msec
"R" or "D" or manual mode	<= -10 °C (14 °F)	3,220 msec
"R" or "D" or manual mode	> -10 °C (14 °F)	2,220 msec

Example of the time required

OBD-II DRIVE CYCLE PATTERN <TARGET CLUTCH 1 (ODD) PRESSURE: 1,400 HPA OR MORE TO 3,000 HPA OR LESS>

The calculated pressure remains -2,000 hPa or more for time required^*.
*: Time required
The time required for the "Rationality-high" monitor depends on the transmission fluid temperature, the shift lever position.

Shift lever position	Transmission fluid temperature	Time required
"D → N" or "R → N" or "R → P"	>= -10 °C (14 °F)	1,220 msec
"D → N" or "R → N" or "R → P"	< -10 °C (14 °F)	2,220 msec
"N" or "P"	All range	220 msec
"R" or "D" or manual mode	<= -10 °C (14 °F)	3,220 msec
"R" or "D" or manual mode	> -10 °C (14 °F)	2,220 msec

Example of the time required

LOGIC FLOW CHARTS (Monitor Sequence) <Target clutch 2 (even) pressure: 1,400 hPa or less>

DTC SET CONDITIONS <TARGET CLUTCH 2 (EVEN) PRESSURE: 1,400 HPA OR LESS>

Check Conditions

Engine speed: 650 r/min or more.
Time since above engine condition: 1.5 seconds or more.
Clutch 2 (even) state: Slip or engaged.
Target clutch 2 (even) pressure: 1,400 hPa or less.

JUDGMENT CRITERIA

Calculated pressure: -1,000 hPa or less. (Time required^*)

*: Time required
The time required for the "Rationality-high" monitor depends on the transmission fluid temperature, the shift lever position.

Shift lever position	Transmission fluid temperature	Time required
"D → N" or "R → N" or "R → P"	>= -10 °C (14 °F)	1,220 msec
"D → N" or "R → N" or "R → P"	< -10 °C (14 °F)	2,220 msec
"N" or "P"	All range	220 msec
"R" or "D" or manual mode	<= -10 °C (14 °F)	3,220 msec
"R" or "D" or manual mode	> -10 °C (14 °F)	2,220 msec

Example of the time required

OBD-II DRIVE CYCLE PATTERN <TARGET CLUTCH 2 (EVEN) PRESSURE: 1,400 HPA OR LESS>

The clutch 2 (even) pressure remains -1,000 hPa or more for time required^*.
*: Time required
The time required for the "Rationality-high" monitor depends on the transmission fluid temperature, the shift lever position.

Shift lever position	Transmission fluid temperature	Time required
"D → N" or "R → N" or "R → P"	>= -10 °C (14 °F)	1,220 msec
"D → N" or "R → N" or "R → P"	< -10 °C (14 °F)	2,220 msec
"N" or "P"	All range	220 msec
"R" or "D" or manual mode	<= -10 °C (14 °F)	3,220 msec
"R" or "D" or manual mode	> -10 °C (14 °F)	2,220 msec

Example of the time required

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?

	Go to Step 2.

	Repair the CAN bus lines. (Refer to GROUP 54C - Troubleshooting .) After repairing the CAN bus line, go to Step 2.

STEP 2. Check whether the DTC is reset.

After the test run, check that the DTC is reset.

Q. Is DTC No. P181F set?

	Replace the transaxle assembly. (Refer to .)

	Intermittent malfunction. (Refer to GROUP 00 - How to Cope with Intermittent Malfunction .)