3.5.7.16 P0729 P0731 P0732 P0733 P0734 P0735 P0736 

1. DTC 

description: 

DTC P0729 6th speed transmission ratio error 

 

DTC P0731 1st speed or M1 speed transmission ratio error 

 

DTC P0732 2 nd speed transmission ratio error 

 

DTC P0733 3rd speed transmission ratio error 

 

DTC P0734 4th speed transmission ratio error 

 

DTC P0735 5th speed transmission ratio error 

 

DTC P0736 Reverse gear transmission ratio error 

The transmission gear shift is controlled by the transmission control unit (TCU). The transmission control unit 
receives the input information from the engine RPM sensor and other vehicle sensors. During each gear shift, it 
selects the time to change gear, controls the gear shift feel and the hydraulic torque converter clutch (TCC). 

2.  Conditions For Setting DTC and The Fault Position : 

DTC Code  DTC Detection Strategy 

Conditions For Setting The DTC 
(Control Strategy) 

Fault Position s 

P0729 

When do not shift ,system 
observed transmission ratio of 
6th speed is over the standard 
value 

P0731 

It is observed that the 
transmission ratio when the 
shift gear is in the 1st speed 
position exceeds the 
calibration value when no gear 
shift is carried out. 

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. Output shaft speed of 

transmission>300 rpm 

1. Automatic 

transmission fluid 

2. Automatic 

transmission fluid 
level 

3.  

AutomaticTransmissi
on assembly 

1323

 
 

P0732 

When do not shift , system 
observed transmission ratio of 
2nd speed is over the standard 
value 

P0733 

When do not shift , system 
observed transmission ratio of 
3rd speed is over the standard 
value 

P0734 

It is observed that the 
transmission ratio when the 
shift gear is in the 4st speed 
position exceeds the 
calibration value when no gear 
shift is carried out. 

P0735 

It is observed that the 
transmission ratio when the 
shift gear is in the 5th speed 
position exceeds the 
calibration value when no gear 
shift is carried out. 

P0736 

It is observed that the 
transmission ratio when the 
shift gear is in the Gear R 
position exceeds the 
calibration value when no gear 
shift is carried out. 

6.  Transmission shift lever is 

not in N speed and parking 
position.  

3. Circuit 

sketch 

1324

 
 

T

C

U

电磁阀

换挡器

档位开关

LEVER

REVERSE

START

VBS5

VBS6

VBS7

V

BS8

VBS9

VBS1

0

O

n

O

ff

1

O

n

O

ff

2

O

n

O

ff

3

O

n

O

ff

4

EMM

INPUT

SHAFT

SPEE

D

SENSOR

OU

TPUT

SHAFT

t

SPE

ED

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 
P0729, P0731, P0732, P0733, P0734, P0735 and P0736 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 P0729 P0731 P0732 P0733 P0734 P0735 P0736 

Yes 

DTCs other than DTCs P0729, P0731, P0732, P0733, P0734, P0735 and P0736 

No 

 

Gears switch 

Main relay 

JF-1

Reverse output 

signal

Start relay JB-2

Shifter 

Electromagnetic 

valve 

1325

 
 

 

 

 

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 switches 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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