3.5.7.21 P0998 P0999 

1. DTC 

description: 

DTC P0998 Electromagnetic valveS6 high current (short circuit) 

 

DTC P0999 Electromagnetic valveS6low current(open circuit) 

The transmission control unit (TCU) uses a variable pressure electromagnetic valve to regulate the hydraulic 
pressure. The hydraulic system controls the clutch in the transmission to realize the torque transmission. 

The transmission control unit (TCU) can control a certain amount of pressure by adjusting the current of the 
electromagnetic valve to enter the clutch and the transmission of the clutch torque is directly related to the current 
of the electromagnetic valve. 

During operation, the transmission control unit evaluates the current actually delivered to the electromagnetic 
valve and compares with the expected. If there is no pre-defined parameter currently, the DTC is set to display 
abnormal load of the transmission control unit. 

2.  Conditions For Setting DTC and The Fault Position : 

DTC Code  DTC 

Detection 

Strategy 

Conditions For Setting The DTC 
(Control Strategy) 

Fault Position s 

P0998 

Feed back message of 
electromagnetic 
valveS6 mean short 
circuit 

P0999 

Feed back message of 
electromagnetic 
valveS6 mean open 
circuit 

1.  Ignition switch is in the “ON” 

position.  

2.      Electromagnetic valve power on 

 

3.  TCU power supply voltage is normal 

1. Electromagnetic 

valve 

2. Electromagnetic 

valve Circuit 

3. TCU 

3. Circuit 

sketch 

1347

 
 

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 
P0998 and P0999 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 P0998 P0999 

Yes 

DTCs other than DTCs P0998 and P0999 

No 

 

Gears switch 

Main relay 

JF-1

Reverse output 

signal

Start relay JB-2

Shifter 

Electromagnetic 

valve 

1348

 
 

 

 

 

2 

Detect TCUpower supply circuit 

See 3.5.7.8 P0603 P0604 P1604 P1701 P1703 

 

 

3 

Detect S6electromagnetic valve resistance 

 

A.    Turn the ignition switch to the OFF position. 

B.  Disconnect the harness connector J-4 of the 

electromagnetic valve. 

C.    Measure the resistance between Terminals 2 and 

1 of the electromagnetic valve harness connector 
J-4. 

Standard resistant value :4.11Ω-4.17Ω 

 

电磁阀线束连接器

J-4

1

8

20

14

9

15

10

16

11

17

12

18

13

19

2

21

3

22

4

23

5

24

6

25

7

26

SL03-0036c

Does it conform to the standard value? 

 

 

 

3 

Detect S6electromagnetic valve circuit 

 

No

Yes 

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

Next 

No

Yes

Replace auto-transmission assembly, refer to 
3.4.7.6 auto-transmission assembly replacement 

Electromagnetic valveharness connectorJ-4

1349

 
 

 

A.  rotated ignition switch to OFF position. 

B.  Disconnect the harness connector J-4 of the 

electromagnetic valve. 

C.    Measure the resistance between Terminal 3 of the 

electromagnetic valve harness connector J-4 and 
Terminal 6 of the automatic control module J-1. 

D.    Measure the resistance between Terminal No.1 of 

the electromagnetic valve harness connector J-4 
and Terminal 7 of the automatic control module 
J-1. 

E.    Turn the ignition switch to the ON position. 

F.  Measure voltage of electromagnetic valve 

harness connector J-4Terminal No.3  and 
reliable grounding 

自动变速器控制模块线束连接器

J-1

1

9

2

10

3

11

4

12

5

13

6

14

7

15

8

16

SL03-0034c

G.    Measure the resistance between Terminal No.1 of the electromagnetic valve harness connector J-4 and secure 

ground wire. 

Results 

Test Items 

Standard Value 

J-4 (3) — J-1(6) 

Less than 3 Ω 

J-4 (1) — J-1(7) 

Less than 3 Ω 

J-4 (3) — Reliable grounding voltage value 

0 V 

J-4 (1) — Reliable grounding resistance value 

Less than 3 Ω 

Does it conform to the standard value? 

 

 

 

4 Replace 

TCU 

Refer to3.5.7.8 replace automatic transmission control module 

 

 

5 

Go to automatic transmission fresh process. 

Refer to3.5.7.4 Automatic transmission refresh process 

No

Yes

Circuit malfunction, repair circuit. 

Next 

Auto-transmissioncontrol module harness connectorJ-1

1350