SANY Crawler Hydraulic Excavator SY215CLC (CUMMINS QSB6.7 engine). Shop Manual - page 28

Troubleshooting

SY215C

LC

7-74

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-
420M  A) and ground
Between harness (from controller pin 67 to CN-
421M  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-420M B Be-

tween controller pin 54 and CN-421M 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-421M

DF-3

CN-420M

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

Troubleshooting

SY215C

LC

7-75

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

CONTROLLER

120

Ω

 RESISTANCE

MONITOR

CAB

CHASSIS HARNESS

PWR

PWR

Troubleshooting

SY215C

LC

7-76

E-12  Monitor displays nothing

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.)

Trouble

Display of monitor is illuminated but no information is 

shown on the screen after machine is powered on. 

Related information

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

ZX215-1005103

CAB

CHASSIS HARNESS

PWR

PWR

CONTROLLER

120

Ω

 RESISTANCE

MONITOR

Troubleshooting

SY215C

LC

7-77

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-131F pin A  to 
controller 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

Troubleshooting

SY215C

LC

7-78

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

3

4

SIGNAL

ZX215-1005299

ECM

CAN

CONTROLLER

COOLANT TEMP
SENSOR

CAB

CHASSIS HARNESS

COOLANT TEMP
SENSOR

Troubleshooting

SY215C

LC

7-79

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

Troubleshooting

SY215C

LC

7-80

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-219M 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-219M 1 to CN-1-110 2 short to 
ground

Resistance

≥

1M

Ω

4

F15 5A

25

21

CN-219M

D-12

1

CN-419F

D-12

CN-133M

D-12

11

25

1

3

4

1

3

4

CN-313F

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

CAB

WIPER SWITCH

PWR

Troubleshooting

SY215C

LC

7-81

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-428M 

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 
perform troubleshooting. 
Between CN-428M 

②

 and controller pin 71 

Resistance

≤

1

Ω

3

Short circuit of 

signal wire

 

★

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

 

Between CN-428M 

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-428M 

②

 and ground

Voltage

0.5V~ 4.5V

5

CN-428M

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

Troubleshooting

SY215C

LC

7-82

E-18  Incorrect arm-out pilot pressure reading

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-422M 

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 
perform troubleshooting.

 

Between CN-422M 

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 
perform troubleshooting. 
Between CN-422M 

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-422M 

②

 and ground

Voltage

0.5V~ 4.5V

5

Trouble

Reading of arm-out pilot pressure is incorrect. 

Related information

CN-422M

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

Troubleshooting

SY215C

LC

7-83

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-426M 

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 
perform troubleshooting. 

Between CN-426M 

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 
perform troubleshooting. 
Between CN-426M 

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-426M 

②

 and ground

Voltage

0.5V~ 4.5V

5

CN-426M

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

Troubleshooting

SY215C

LC

7-84

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-425M 

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 
perform troubleshooting.

 

Between CN-425M 

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 
perform troubleshooting.

 

Between CN-425M 

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-425M 

②

 and ground

Voltage

0.5V~ 4.5V

5

 CN-425M

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

Troubleshooting

SY215C

LC

7-85

E-21  Incorrect bucket-curl pilot pressure reading

Trouble

Bucket-curl 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-424M 

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 
perform troubleshooting. 
Between CN-424M 

②

 and controller pin 69 

Resistance

≤

1

Ω

3

Short circuit of 

signal wire

 

★

 Turn engine start switch to OFF position. Keep it at OFF position to 
perform troubleshooting. 
Between CN-424M 

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-424M 

②

 and ground

Voltage

0.5V~ 4.5V

5

CN-424M

DF-3

5V

2

3

1

75

55

69

ZX215-1005112

CHASSIS HARNESS

CAB

SIGNAL

GND WIRE

CONTROLLER

SENSOR 5V

SENSOR GND WIRE

BUCKET CURL
PRESS SENSOR

BUCKET CURL
PRESS SENSOR

Troubleshooting

SY215C

LC

7-86

E-22  Incorrect bucket-dump pilot pressure reading

Trouble

Bucket-dump 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-427M 

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 
perform troubleshooting.

 

Between CN-427M 

②

 and controller pin 50  Resistance

≤

1

Ω

3

Short circuit of 

signal wire

 

★

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

 

Between CN-427M 

②

 and ground

Resistance

≥

2M

Ω

4

Failure of sensor

 

★

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

 

Between CN-427M 

②

 and ground

Voltage

0.5V~ 4.5V

5

CN-427M

DF-3

5V

2

3

1

75

55

50

ZX215-1005113

CHASSIS HARNESS

CAB

SIGNAL

GND WIRE

CONTROLLER

SENSOR 5V

SENSOR GND WIRE

BUCKET DUMP
PRESS SENSOR

BUCKET DUMP
PRESS SENSOR

Troubleshooting

SY215C

LC

7-87

E-23  Incorrect swing pilot pressure reading

Trouble

Swing 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-423M 

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 
perform troubleshooting.

 

Between CN-423M 

②

 and controller pin 68 

Resistance

≤

1

Ω

3

Short circuit of 

signal wire

 

★

 Turn engine start switch to OFF position. Keep it at OFF position to 
perform troubleshooting. 
Between CN-423M 

②

 and ground

Resistance

≥

2M

Ω

4

Failure of sensor

 

★

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

 

Between CN-423M 

②

 and ground

Voltage

0.5V~ 4.5V

5

CN-423M

DF-3

5V

2

3

1

75

55

68

ZX215-1005114

CHASSIS HARNESS

CAB

SIGNAL

GND WIRE

CONTROLLER

SENSOR 5V

SENSOR GND WIRE

SWING PILOT 
PRESS SENSOR

SWING PILOT 
PRESS SENSOR

Troubleshooting

SY215C

LC

7-88

E-24  Incorrect left travel pilot pressure reading

Trouble

Left Travel 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-420M 

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 
perform troubleshooting.

 

Between CN-420M 

②

 and controller pin 49 

Resistance

≤

1

Ω

3

Short circuit of 

signal wire

 

★

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

 

Between CN-420M 

②

 and ground

Resistance

≥

2M

Ω

4

Failure of sensor

 

★

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

 

Between CN-420M 

②

 and ground

Voltage

0.5V~ 4.5V

5

 CN-420M

DF-3

5V

2

3

1

75

55

49

ZX215-1005115

CHASSIS HARNESS

CAB

CONTROLLER

SENSOR 5V

SENSOR GND WIRE

LEFT TRAVEL PILOT 
PRESSURE SENSOR

SIGNAL

GND WIRE

LEFT TRAVEL PILOT 
PRESSURE SENSOR

Troubleshooting

SY215C

LC

7-89

E-25  Incorrect right travel pilot pressure reading

Trouble

Right travel 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-421M 

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 
perform troubleshooting. 
Between CN-421M 

②

 and controller pin 67 

Resistance

≤

1

Ω

3

Short circuit of 

signal wire

 

★

 Turn engine start switch to OFF position. Keep it at OFF position to 
perform troubleshooting. 
Between CN-421M 

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-421M 

②

 and ground

Voltage

0.5V~ 4.5V

5

 CN-421M

DF-3

5V

2

3

1

75

55

67

ZX215-1005116

CHASSIS HARNESS

CAB

CONTROLLER

SENSOR 5V

SENSOR GND WIRE

RIGHT TRAVEL PILOT 
PRESSURE SENSOR

SIGNAL

GND WIRE

RIGHT TRAVEL PILOT 
PRESSURE SENSOR