SANY Crawler Hydraulic Excavator SY195C9, SY205C9, SY215C9, SY225C9. Service Manual - page 28

Troubleshooting

E-6  Work equipment does not work

Trouble

The machine is motionless while operated after starting. 

Related information

Possible causes and standard value in normal 

state

Cause

Standard value in normal state/Remarks on troubleshooting

1

Failure of lockout  

switch

●

 Turn engine start switch to OFF position. Start the engine and keep it
running to perform troubleshooting. 

Item

Lockout control lever

Resistance

Between wire 105# and wire 27# 

LOCK 

≤

1 

Ω

FREE

  

≥

1M 

Ω

2

Short circuit of 

wire harness 

(grounded)

●

 Turn engine start switch to OFF position. Keep it at OFF position to per-
form troubleshooting.

Between 105# and ground

Resistance

≥

1M 

Ω

3

Failure of coil 

inside lockout 

solenoid valve

●

 Turn engine start switch to OFF position. Keep it at OFF position to per-
form troubleshooting.

Between CN-136F 1 and 2

Resistance

 About 34 

Ω

4

105

 CN-661F

1

1

0

2

105

606

27

3 4 5

1

2

3 4 5

8

1

8

1

2

1

2

27

S-16

CN-161F

(S-16)

CN-136F

AMP-2

 CN-106F

AMP-2

1

2

2

10

12

2

10

12

1

2

27

F16  10A

21

B-

ZX215-1005098

PILOT SWITCH

PILOT SOLENOID VALVE

CHASSIS HARNESS

CAB

7-73

Troubleshooting

E-7 Boom-raise speed or power is low

Trouble

Boom-raise speed or power is low. 

Related information

Pilot pressure of the boom in operation can be 

checked on the monitor. 

Possible causes and standard value in nor-

mal state

Cause

Standard value in normal state/Remarks on troubleshooting

1

Failure of sen-

sor

●

 Turn engine start switch to OFF position. Start the engine and keep it run-
ning to perform troubleshooting.

Levers in NEUTRAL, boom-raise pressure signal

Pressure

0 KG

Lever in operation, boom-raise pressure signal

0~39 KG

2

Short circuit 

of harness 

(grounded)

●

 Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting.

Between harness ( from controller pin 70 to CN-126M 
A) and ground

Resistance

≥

1M 

Ω

3

Open circuit of 

harness

●

  Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting.

Between controller pin 54 and CN-126M B

Resistance

≤

1 

Ω

4

Failure of con-

troller

No troubleshooting can be done due to internal failure. (Failure lies in the con-
troller if the reasons above are ruled out)

  CN-126M

DF-3

A

B

C

56

54

70

ZX215-1005099

CHASSIS HARNESS

CAB

BOOM UP 
PRESS. SENSOR

SIGNAL

5V

GND WIRE

CONTROLLER

SENSOR 5V

SENSOR GND WIRE

BOOM UP
PRESSURE SENSOR

Troubleshooting

E-8  Arm speed or power is low

Trouble

Arm speed or power is low during operation.

Related information

Pilot pressure of the arm in operation can be checked on the monitor. 

Possible causes and standard value in normal state

Cause

Standard value in normal state/Remarks on troubleshooting

1

Failure of sen-

sor

●

 Turn engine start switch to OFF position. Start the engine and keep it run-
ning to perform troubleshooting. 

Levers in NEUTRAL, arm-in and arm-out pressure 
signals

Pressure

0 KG

Levers in operation, arm-in and dump pressure 
signal

0~39 KG

2

Short circuit 

of harness 

(grounded)

●

 Turn engine start switch to OFF position. Keep it at OFF position to per-
form troubleshooting. 

Between harness (from controller pin 71 to CN-
128M  A) and ground
Between harness (from controller pin 52 to CN-
122M  A) and ground

Resistance

≥

1M 

Ω

3

Open circuit of 

harness

●

 Turn engine start switch to OFF position. Keep it at OFF position to per-
form troubleshooting. 

Between controller pin 54  and CN-128M B
Between controller pin 54 and CN-122M B

Resistance

≤

1 

Ω

4

Failure of con-

troller

No troubleshooting can be done due to internal failure. (Failure lies in the 
controller if the reasons above are ruled out)

52

71

54

56

A

C

B

A

C

B

CN-122M

DF-3

CN-128M

DF-3

ZX215-1005119

CHASSIS HARNESS

SIGNAL

GND WIRE

ARM-IN
PRESS. SENSOR

GND WIRE

ARM-OUT
PRESS. SENSOR

5V

5V

SIGNAL

CONTROLLER

ARM-OUT
PRESS SENSOR

ARM-IN
PRESS SENSOR

SENOSR 5V

CAB

SENSOR GND WIRE

Troubleshooting

E-9  Bucket speed or power is low

Trouble

Bucket speed or power  is low during operation. 

Related information

Pilot pressure of the bucket can be checked on the monitor. 

Possible causes and standard value in normal state

Cause

Standard value in normal state/Remarks on troubleshooting

1

Failure of 

sensor

●

 Turn engine start switch to OFF position. Start the engine and keep it running
to perform troubleshooting.

Levers in NEUTRAL, bucket-curl/dump pressure signals

Pressure

0 KG

Levers in operation, bucket-curl/dump pressure signals

0~39 KG

2

Short circuit 

of harness 

(grounded)

●

  Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting.

Between harness (from controller pin 69 to CN-124M  A) 
and ground
Between harness (from controller pin 50 to CN-127M  A) 
and ground

Resistance

≥

1M 

Ω

3

Open circuit 

of harness

●

  Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting.

Between controller pin 54 and CN-124M B
Between controller pin 54 and CN-127M B

Resistance

≤

1 

Ω

4

Defective 

bucket  

con

fl

 uence 

solenoid 

valve

●

 Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting.

Between CN-134F 1 and 2

Resistance

About 17.5 

Ω

5

Failure of 

controller

No troubleshooting can be done due to internal failure. (Failure lies in the control-
ler if the reasons above are ruled out)

Troubleshooting

A

C

B

A

C

B

1

2

CN-127M

DF-3

CN-124M

DF-3

  CN-134F
AMP-2

50

69

54

56

99

ZX215-1005100

BUCKET CONFLUENCE
PROPORTIONAL VALVE

5V

5V

CAB

CHASSIS HARNESS

SIGNAL

GND WIRE

BUCKET-CURL
PRESS. SENSOR

SIGNAL

GND WIRE

BUCKET-DUMP
PRESS. SENSOR

SIGNAL

GND WIRE

BUCKET 
CONFLUENCE SIGNAL

CONTROLLER

BUCKET-CURL
PRESS. SENSOR

BUCKET-DUMP
PRESS. SENSOR

SENOSR 5V

SENSOR GND WIRE

7-77

Troubleshooting

E-10  Travel speed or power is low

Trouble

Travel speed or power is low during operation. 

Related information

Pilot pressure of travel operation can be checked on the monitor. 

Possible causes and standard value in normal state

Cause

Standard value in normal state/Remarks on troubleshooting

1

Failure of sen-

sor

●

 Turn engine start switch to OFF position. Start the engine and keep it run-
ning to perform troubleshooting. 

Levers in NEUTRAL, left and right travel pressure 

signals

Pressure

0 KG

Levers in operation,  left and right travel pressure 

signals

0~39 KG

2

Short circuit 

of harness 

(grounded)

●

 Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting.

Between harness (from controller pin 49  to CN-
120M  A) and ground
Between harness (from controller pin 67 to CN-
121M  A) and ground

Resistance

≥

1M 

Ω

3

Open circuit of 

harness

●

 Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting. 

Between controller pin 54 and CN-120M B Be-

tween controller pin 54 and CN-121M B

Resistance

≤

1 

Ω

4

Failure of con-

troller

No troubleshooting can be done due to internal failure. (Failure lies in the con-
troller if the reasons above are ruled out)

A

C

B

A

C

B

67

49

54

56

CN-121M

DF-3

CN-120M

DF-3

ZX215-1005101

RIGHT TRAVEL 
PRESS. SENSOR

LEFT TRAVEL 
PRESS. SENSOR

5V

SIGNAL

GND WIRE

5V

SIGNAL

GND WIRE

CONTROLLER

RIGHT TRAVEL
PRESS SENSOR
LEFT TRAVEL 
PRESS SENSOR

SENOSR 5V

SENSOR GND WIRE

CAB

CHASSIS HARNESS

7-78

Troubleshooting

E-11  Blank monitor display

Trouble

Monitor display is blank after the machine is powered on.

Related information

Possible causes and standard value in normal state

Cause

Standard value in normal state/Remarks on troubleshooting

1 Failure of fuse

●

 Turn engine start switch to OFF position. Then, keep it at ON position to
perform troubleshooting. 

Between wire 22# and ground

Voltage

About 24V

Between wire 29# and ground

About 24V

2

Open circuit of 

wire harness

●

 Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting. 

Between CN-7-705 pin 8 and CN-241F pin 3

Resistance

≤

1 

Ω

Between CN-7-705 pin 9 and CN-241 pin 1

≤

1 

Ω

Between CN-7-705 pin 10# and ground

≤

1 

Ω

3

Short circuit of 

wire harness 

(grounded)

●

 Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting. 

Between harness (from CN-7-705 pin 8 to CN-241 
pin 3) and ground

Resistance

≥

1M 

Ω

Between harness (from CN-7-705 pin 9 to CN-241 
pin 1) and ground

≥

1M 

Ω

4

Failure of 

monitor

No troubleshooting can be done for it is internal failure. (If it is not caused by 
one of the factors listed above, it should be the failure of monitor.)

60

78

CANH

CANL

CANH

CANL

CN-1-112

(D-3)

1

2

1

2

CANH

CANL

CN-7-705

(D-12)

CN-1-111

(D-6)

CN-241F

(D-12)

1

2

3

1

2

3

3
1

3
1

22

29

20

21

F1 20A

F10 5A

29

22

0

3
4
8

9

10

12

3
4
8

9

10

12

3

4

8

9

10

12

ZX215-1005102

PWR

PWR

CONTROLLER

120

ȍ

 RESISTANCE

MONITOR

CAB

CHASSIS HARNESS

7-79

Troubleshooting

60

78

CANH

CANL

CANH

CANL

CN-1-112

(D-3)

1

2

1

2

CANH

CANL

CN-7-705

(D-12)

CN-1-111

(D-6)

CN-241F

(D-12)

1

2

3

1

2

3

3
1

3
1

22

29

20

21

F1 20A

F10 5A

29

22

0

3
4
8

9

10

12

3
4
8

9

10

12

3

4

8

9

10

12

ZX215-1005102

PWR

PWR

CONTROLLER

120

ȍ

 RESISTANCE

MONITOR

CAB

CHASSIS HARNESS

E-12  Monitor displays nothing

Trouble

Display of monitor is illuminated but no information is 

shown on the screen after machine is powered on. 

Related information

Possible causes and standard value in normal state

Cause

Standard value in normal state/Remarks on troubleshooting

1

Failure of resis-

tance

●

 Turn engine start switch to OFF position. Keep it at OFF position to
perform troubleshooting. 

Between CN-1-112  1 and 2 

Resistance

120  

Ω

2

Open circuit of 

wire harness

●

 Turn engine start switch to OFF position. Keep it at OFF position to
perform troubleshooting.

Between CN-7-705 pin 3 and controller pin 60 

Resistance

≤

1 

Ω

Between CN-7-705 pin 4  and controller pin 78 

≤

1 

Ω

3

Short circuit of 

wire harness 

(grounded)

●

 Turn engine start switch to OFF position. Keep it at OFF position to
perform troubleshooting. 

Between harness (from CN-7-705 pin 3  to con-
troller pin 60)  and ground

Resistance

≥

1M 

Ω

Between harness (from CN-7-705 pin 4  to control-
ler pin 78)  and ground

≥

1M 

Ω

4

Failure of monitor 

or controller

No troubleshooting can be done for it is internal failure. (If it is not one of 

the failures stated above, it should be the failure of monitor or controller.)

Troubleshooting

E-13  Dual speed travel not functioning

Trouble

Only low speed travel is functioning during operation.

Related information

Press the Hi/Lo button on the monitor to change travel speed. 

Possible causes and standard value in 

normal state

Cause

Standard value in normal state/Remarks on troubleshooting

1

Failure of dual 

speed travel 

solenoid valve

●

  Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting. 

Between CN-131F A and B

Resistance

About 17.5 

Ω

2

Open circuit of 

wire harness

●

  Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting. 

Between CN-132F pin A  and controller pin 100 

Resistance

≤

1 

Ω

Between CN-132F pin B  and controller pin 55 

≤

1 

Ω

3

Short circuit of 

wire harness 

(grounded)

●

  Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting. 

Between harness (from CN-132F pin A  to con-

troller pin (100)  and ground

Resistance

≥

1M 

Ω

4

100

55

B

A

AMP-2

CN-132F

ZX215-1005104

GND WIRE

HIGH SPEED TRAVEL 
SOLENOID VALVE

GROUND

CONTROLLER

SIGNAL

CAB

CHASSIS HARNESS

HIGH SPEED TRAVEL 
SOLENOID VALVE

7-81

Troubleshooting

E-14  Incorrect engine coolant reading

Trouble

Engine coolant temperature sensor cannot correctly re

fl

 ect cur-

rent coolant temperature. 

Related information

Coolant temperature can be checked on the monitor. 

Possible causes and standard value in normal state

Cause

Standard value in normal state/Remarks on troubleshooting

1

Failure of coolant 

temperature sen-

sor

Standard values for engine coolant temperature sensor 

50°C

80 

Ω

60°C

 56.3 

Ω

80°C

29.5 

Ω

100°C

16.5 

Ω

106°C

14.3 

Ω

120°C

10 

Ω

2

Open circuit of 

lead

●

   Turn engine start switch to OFF position. Keep it at OFF position to
perform troubleshooting.

Between wire 510# and controller pin 30 

Resistance

≤

1 

Ω

3

Short circuit of 

lead (grounded)

●

   Turn engine start switch to OFF position. Keep it at OFF position to
perform troubleshooting.

Between wire 510# and ground

Resistance

≥

1M 

Ω

4

Lead short to 24V 

circuit

●

 Turn engine start switch to OFF position. Keep it at OFF position to
perform troubleshooting.

 Wire 510# to ground

Voltage

≤

1V 

᥻ࠊ఼

ދै⎆⏽ᑺӴᛳ఼

ᴳ

㒓

䑿

䔺

ᅸ

偊

偒

510

30

ZX215-1005105

7-82

Troubleshooting

E-15 Incorrect fuel level reading

Trouble

Engine fuel level sensor cannot correctly re

fl

 ect current fuel level. 

Related information

Fuel level can be checked on the monitor.

Possible causes and standard value in normal 

state

Cause

Standard value in normal state/Remarks on troubleshooting

1

Fuel level sen-

sor error

●

 Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting. 

Pin

Fuel level

Resistance

Between wire 509#  and ground

FULL (Upper limit)

Approx. 10 

Ω

EMPTY (Lower limit)

85-95 

Ω

2

Open circuit of 

lead

●

 Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting.

Between wire 509#  and controller pin 11 

Resistance

≤

1 

Ω

3

Short circuit of 

lead (ground-

ed)

●

 Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting. 

Between wire 509#  and ground

Resistance

≥

1M 

Ω

4

Lead short to 

24V 

●

 Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting. 

Wire 509#  grounded

Voltage

  

≤

1V 

509

11

ZX215-1005106

CONTROLLER

FUEL LEVEL 
SENSOR

CAB

CHASSIS HARNESS

7-83

Troubleshooting

E-16  Wiper does not work

Trouble

Wiper does not work

Related information

Possible causes and standard value in normal 

state

Cause

Standard value in normal state/Remarks on troubleshooting

1

Internal Fail-

ure of wiper 

motor

●

 Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting. 

Between wiper wire 25#  and ground

Resistance

>10 

Ω

2

Open circuit of 

lead

●

 Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting. 

Between CN-241F 1 and CN-1-110 (2)

Resistance

≤

1 

Ω

Between wiper switch wire 35L#  and CN-1-110 (5)

≤

1 

Ω

Between wiper switch wire 35L#  and CN-1-110 (4)

≤

1 

Ω

3

Short circuit of 

lead (ground-

ed)

●

 Turn engine start switch to OFF position. Keep it at OFF position to perform
troubleshooting. 

Harness from CN-241F 1 to CN-1-110 2 short to 
ground

Resistance

≥

1M 

Ω

4

F15 5A

25

21

CN-241M

D-12

1

CN-121F

D-12

CN-132M

D-12

11

25

1

3

4

1

3

4

CN-113F

D-12

4

36
35L
35H

CN-1-110

D-6

4

5

3

2

4

5

3

2

36
35L

35H

25

M

ZX215-1005107

PWR

CAB

WIPER SWITCH

Troubleshooting

E-17  Incorrect arm-in pilot pressure reading

Trouble

Reading of arm-in pilot pressure is incorrect. 

Related information

Possible causes and standard value in normal state

Cause

Standard value in normal state/Remarks on troubleshooting

1

Failure of 5V 

power supply

●

 Turn engine start switch to OFF position. Then, keep it at ON position to
perform troubleshooting. 

Between CN-128M 

①

 and 

③

Voltage

Approx. 5V

2

Open circuit of 

signal wire

●

Turn engine start switch to OFF position. Keep it at OFF position to per-
form troubleshooting. 

Between CN-128M 

②

 and controller pin 71 

Resistance

≤

 

Ω

3

Short circuit of 

signal wire

●

 Turn engine start switch to OFF position. Keep it at OFF position to per-
form troubleshooting. 

Between CN-128M 

②

 and ground

Resistance

≥

2M 

Ω

4

Failure of sen-

sor

●

 Turn engine start switch to OFF position. Then, keep it at ON position to
perform troubleshooting.

 Between CN-128M 

②

 and ground

Voltage

0.5V~ 4.5V

5

CN-128M

DF-3

2

3

1

75

55

71

ZX215-1005108

CHASSIS HARNESS

CAB

ARM IN

PRESS SENSOR

SIGNAL

5V

GND WIRE

CONTROLLER

SENSOR 5V

SENSOR GND WIRE

ARM IN
PRESS SENSOR

7-85

Troubleshooting

E-18  Incorrect arm-out pilot pressure reading

Trouble

Reading of arm-out pilot pressure is incorrect. 

Related information

Possible causes and standard value in normal 

state

Cause

Standard value in normal state/Remarks on troubleshooting

1

Failure of 5V 

power supply

●

 Turn engine start switch to OFF position. Then, keep it at ON position to
perform troubleshooting. 

Between CN-122M 

①

 and 

③

Voltage

About 5V

2

Open circuit of 

signal wire

●

 Turn engine start switch to OFF position. Keep it at OFF position to per-
form troubleshooting. 
Between CN-122M 

②

 and controller pin 52 

Resistance

≤

1 

Ω

3

Short circuit of 

signal wire

●

 Turn engine start switch to OFF position. Keep it at OFF position to per-
form troubleshooting. 

Between CN-122M 

②

 and ground

Resistance

≥

2M 

Ω

4

Failure of sen-

sor

●

Turn engine start switch to OFF position. Then, keep it at ON position to
perform troubleshooting. 

Between CN-122M 

②

 and ground

Voltage

0.5V~ 4.5V

5

CN-122M

DF-3

2

3

1

75

55

52

ZX215-1005109

5V

CHASSIS HARNESS

CAB

ARM OUT

PRESS SENSOR

SIGNAL

GND WIRE

CONTROLLER

SENSOR 5V

SENSOR GND WIRE

ARM OUT
PRESS SENSOR

7-86

Troubleshooting

E-19  Incorrect boom-raise pilot pressure reading

Trouble

Incorrect Boom-Raise Pilot Pressure Reading

Related information

Possible causes and standard value in normal 

state

Cause

Standard value in normal state/Remarks on troubleshooting

1

Failure of 5V 

power supply

●

 Turn engine start switch to OFF position. Then, keep it at ON position to
perform troubleshooting. 

Between CN-126M 

①

 and 

③

Voltage

About 5V

2

Open circuit of 

signal wire

●

 Turn engine start switch to OFF position. Keep it at OFF position to per-
form troubleshooting. 

Between CN-126M 

②

 and controller pin 70 

Resistance

≤

1 

Ω

3

Short circuit of 

signal wire

●

 Turn engine start switch to OFF position. Keep it at OFF position to per-
form troubleshooting. 

Between CN-126M 

②

 and ground

Resistance

≥

2M 

Ω

4

Failure of sen-

sor

●

Turn engine start switch to OFF position. Then, keep it at ON position to
perform troubleshooting. 

Between CN-126M 

②

 and ground

Voltage

0.5V~ 4.5V

5

CN-126M
DF-3

2

3

1

75

55

70

ZX215-1005110

CHASSIS HARNESS

CAB

SIGNAL

5V

GND WIRE

CONTROLLER

SENSOR 5V

SENSOR GND WIRE

BOOM UP
PRESS SENSOR

BOOM UP

PRESS SENSOR

7-87

Troubleshooting

E-20  Incorrect boom-lower pilot pressure reading

Trouble

Boom-Lower pilot pressure reading is incorrect. 

Related information

Possible causes and standard value in normal 

state

Cause

Standard value in normal state/Remarks on troubleshooting

1

Failure of 5V 

power supply

●

 Turn engine start switch to OFF position. Then, keep it at ON position to
perform troubleshooting. 

Between CN-125M 

①

 and 

③

Voltage

About 5V

2

Open circuit of 

signal wire

●

 Turn engine start switch to OFF position. Keep it at OFF position to per-
form troubleshooting. 

Between CN-125M 

②

 and controller pin 51 

Resistance

≤

1 

Ω

3

Short circuit of 

signal wire

●

 Turn engine start switch to OFF position. Keep it at OFF position to per-
form troubleshooting. 

Between CN-125M 

②

 and ground

Resistance

≥

2M 

Ω

4

Failure of sen-

sor

●

Turn engine start switch to OFF position. Then, keep it at ON position to
perform troubleshooting. 

Between CN-125M 

②

 and ground

Voltage

0.5V~ 4.5V

5

 CN-125M

DF-3

2

3

1

75

55

51

ZX215-1005111

5V

CHASSIS HARNESS

CAB

SIGNAL

GND WIRE

CONTROLLER

SENSOR 5V

SENSOR GND WIRE

BOOM DOWN
PRESS SENSOR

BOOM DOWN

PRESS SENSOR