8 Troubleshooting 

5. Maintenance 

guide: 

Replace Automatictransmission assembly , refer to3.5.7.6 Automatictransmission assembly replacement 

 

 

 

Yes

No

Refer to 2.2.7.3 Intermittent Fault Inspection for 
intermittent fault. 

1327

 
 

 

3.5.7.17 P0741 P0742 P0744 

1. DTC 

description: 

DTC P0741 Hydraulic torque converter clutch in the lock status 

 

DTC P0742 Hydraulic torque converter clutch lock in the lock status 

 

DTC P0744 Clutch slippage error of hydraulic torque converter 

The automatic transmission controls the hydraulic torque converter clutch to lock or separate through the 
hydraulic control system. 

The piston pressure of the hydraulic torque converter lock clutch  is decided by pressure controllable 
electromagnetic valve (VBS). During operation, the transmission control unit (TCU) compares with the expected 
by calculating the torque converter slide speed, If the torque converter slip sheet is not within the predefined 
parameters, DTC will be set to indicate the torque converter lockout . 

2.  Conditions for setting DTC and the fault position : 

DTC code 

DTC detection strategy 

Conditions for setting the DTC (control 

ftrategy) 

Fault Position s 

P0741 

When requesting Lock, 
the hydraulic converter 
always keeps Open. 
When requiring Lock, 
the slippage revolution 
speed is higher than 
50rpm and the time of 
duration is more than 
0.5s. 

P0742 

When requesting Open, 
the hydraulic converter 
always keeps Lock. 
When requiring Open, 
the slippage revolution 
speed is lower than 
50rpm, the engine torque 
is more than 150Nm, and 
the time of duration is 
more than 0.5s. 

P0744 

The sliding speed of the 
hydraulic torque 
converter is not 
controlled. The duration 
is more than 0.5s. 

1.  ignition switch is in ON position 

2.  Engine speed >300 rpm 

3.  Engine is in the LHM 

4.  Transmission oil temperature >0°C 

5.  Transmission does not in the shift 

process. 

6.  Shift lever is in the D gear position 

1. Automatic 

transmission fluid 

2. Automatic 

transmission fluid 
level 

3.

 AutomaticTrans
mission assembly 

1328

 
 

3. Circuit 

sketch 

T

C

U

电磁阀

换挡器

档位开关

LEVER

REVERSE

START

VBS5

VBS6

VBS7

VBS8

VBS

9

VBS1

0

O

n

O

ff

1

O

n

O

ff2

O

n

O

ff3

O

n

O

ff

4

EMM

INPU

T

SHAFT

SPEED

SE

NSOR

OUTPU

T

SHAFT

t

SPEED

SENSOR

25

26

10

11

9

8

13

12

24

23

22

21

20

7

6

5

4

3

2

J-4

J-4

J-4

J-4

J-4

J-4

J-4

J-4

J-4

J-4

J-4

J-4

J-4

J-4

J-4

J-4

J-4

J-4

J-4

J-4

1

18

8

1

3

2

12

14

4

11

12

9

10

15

2

1

4

3

6

5

7

7

J-5

5

16

17

J-5

4

J-5

1

J-5

6

J-5

2

J-5

3

4

11

10

10

15

3

CAN H

启动继电器

倒车信号

输出

主继电器

JF-1

IG2

JB-2

CAN L

10

20

J-3

J-1

J-3

J-2

J-2

J-3

J-3

J-3

J-1

8

J-3

J-3

J-3

J-3

J-3

J-3

J-3

J-3

J-1

J-1

J-1

J-1

J-1

J-1

J-1

J-1

J-1

J-1

J-1

J-1

IF36

NL03-2005c

 

4. Diagnostic 

procedures: 

Note: Before carrying out this diagnosis step, observe the data list on fault diagnosis tester and analyze the 
accuracy of the data, as these will help with quick diagnosis. 

1 

Read the fault code again after clearing away the fault code to check if fault codes, except DTC 
P0741, P0742 and P0744 exist in the control system. 

A.    Connect fault diagnosis tester to the datalink connector. 

B.  Rotated ignition switch to ON position 

C.    Switch on fault diagnostic device power supply 

D.  Clear DTC code. 

E.    Reset reading fault code, and check if DTCs meet setting condition of fault code in current 

DTC Codes Shown 

To Step 

DTC P0741 P0742 P0744 

Yes 

DTCs other than DTCs P0741, P0742 and P0744 

No 

Gears switch 

Main relay 

JF-1

Reverse output 

signal

Start relay JB-2

Shifter 

Electromagnetic 

valve 

1329

 
 

 

 

 

2 

Check if the automatic transmission leaks oil. 

 

 

 

3 

Check if the automatic transmission oil level and oil quality accord with the standard. 

See 3.5.7.2 Automatic transmission oil level inspection procedures 

 

 

 

4 

Check if    the automatic transmission has obvious mechanical damage. 

 

 

 

5 Replace 

AutomaticTransmission 

assembly 

Replace AutomaticTransmission assembly , refer to3.5.7.6 AutomaticTransmission assembly replacement 

 

 

6 

Go to automatic transmission fresh process. 

Refer to3.5.7.4 Automatic transmission refresh process 

 

 

7 

Use fault diagnosis tester to confirm if DTC is stored again. 

A.    Connect fault diagnosis tester to the data link connector. 

B.  Rotated ignition switch to ON position. 

C.    Clear DTC code. 

D.    Start and run the engine at idle speed to warm up the engine for at least 5min. 

E.  Read control system DTC code again to confirm that the system has no DTC code exported. 

 

No

Yes

Refer to3.4.7.6 fault diagnosis code (DTC) chapter 
index

No

Yes

Refer to 3.4.7.3 Replacement Procedure of 
Automatic Transmission Oil to fill or replace 
automatic transmission oil.

No

Yes

Repair or replace the damaged part 

Yes

No

Repair or replace the fault part 

Next

Next

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