SANY Crawler Hydraulic Excavator SY215CLC (CUMMINS QSB6.7 engine). Shop Manual - page 24

Troubleshooting

SY215C

LC

7-4

1.  When carrying out troubleshooting, do not 

hurry to disassemble the components.

If components are disassembled immedi-
ately any failure occurs: 

 

●

Parts that have no connection with the 
failure or other unnecessary parts will 
be disassembled.

 

●

It will become impossible to find the 
cause of the failure.

It will also cause a waste of man-hours, 
parts, or oil or grease, and at the same 
time, will also lose the confidence of the 
user or operator.

For this reason, when carrying out 
troubleshooting, it is necessary to carry out 
thorough prior investigation and to carry 
out troubleshooting in accordance with the 

fi

 xed procedure.

2.  Points to ask user or operator:

1)  Have any other problems occurred 

apart from the problem that has been 
reported?

2)  Was there anything strange about the     

machine before the failure occurred?

3)  

Did the failure occur suddenly, or were  
there problems with the machine condi-
tion before this?

4)  Under what conditions did the failure 

occur?

5)  Had any repairs been carried out before 

the failure? When were these repairs 
carried out?

6)  Has the same kind of failure occurred 

before?

3.  Check before troubleshooting

1)  Check the oil level.

2)  Check for any external leakage of oil 

from the piping or hydraulic equipment.

Troubleshooting

SY215C

LC

7-5

3)  Check the travel of the control levers.

4)  Check the stroke of the control valve 

spool.

5)  Other maintenance items can be 

checked externally, so check any item 
that is considered to be necessary.

4.  Con

fi

 rming failure

 

●

Confirm the extent of the failure yourself, 
and judge whether to handle it as a real 
failure or as a problem with the method of 
operation, etc.

 

★

When operating the machine to reenact 
the troubleshooting symptoms, do not 
carry out any investigation or measure-
ment that may make the problem 
worse.

5.  Troubleshooting

 

●

Use the results of the investigation and 
inspection in Items 2 – 4 to narrow down 
the causes of failure, then use the trouble-
shooting 

fl

 owchart to locate the position of 

the failure exactly.

 

★

The basic procedure for troubleshoot-
ing is as follows.

1)  Start from the simple points.

2)  Start from the most likely points.

3)  Investigate other related parts or infor-

mation.

6.  Measures to remove root cause of failure

 

●

 Even if the failure is repaired, if the root 
cause of the failure is not repaired, the 
same failure will occur again. To prevent 
this, always investigate why the problem 
occurred. Then, remove the root cause.

Troubleshooting

SY215C

LC

7-6

7.2  Sequence of Events in Troubleshooting

Offi ce

Jobsite

Step 6

 

●

Start and operate the machine to con

fi

 rm the condi-

tions and judge if there is really a failure.

Re-enacting the failure

Step 1

1) When a request of repairs is received, 

fi

 rst ask the 

following points:

 

●

Name of customer

 

●

Type, serial number of machine

 

●

Details of jobsite, etc.

2) Ask questions to gain an outline of the problem

 

●

Condition of failure

 

●

Work being carried out when the failure occurs

 

●

Operating environment

 

●

 Past history, details of maintenance,etc.

Examination & con

fi

 rmation of symptoms

   Breakdown

！ 

Repair at jobsite

Step 8

Step 2

1) Refer to "Troubleshooting" on this 
     manual to 

fi

 nd out the locations of 

     possible causes

.

Pinpoint the cause of the failure

Step 3

1) Look at the table of troubleshooting tools in the shop 

manual and prepare the necessary tools.

 

●

T-adapter

 

●

Hydraulic pressure gauge etc.

 

●

Look in the parts book and prepare

necessary replacement parts.

Preparation of troubleshooting tools

Repair at workshop

Step 8

Machine 
Volume

Shop manual

Step 4

Go to jobsite

Ask operator questions to con

fi

 rm details of failure

？

 

●

Pinpoint locations of failure (carry 
out troubleshooting)

 

●

Decide actions to take

Step 5

 

●

Did the failure occur suddenly?

 

●

Have any repairs been carried out before the failure 

occurs?

 

●

Was there anything strange about 
the machine before the failure 
occurs?

Step 7

 

●

Checks before starting

 

●

Other check items.

2) See the troubleshooting section in the shop manual,  

select a troubleshooting flowchart that matches the 
symptoms, and carry out troubleshooting.

1) Before starting troubleshooting, locate 

and repair simple failures.

Troubleshooting

SY215C

LC

7-7

7.3 Troubleshooting Procedures

If some phenomenon occurs on a machine 
that looks like a failure, identify the corre-
sponding troubleshooting No. and proceed to 
the explanations for diagnosis.

Follow six steps listed below to diagnose 
and analyze for troubleshooting, and find the 
causes and work out the corresponding meth-
ods.

1.  Read related technical manuals in detail. 

Have a knowledge of related system, 
principle of operation, and structure, 
function and technical specification of 
parts. 

2.  Ask operator

Before checking, ask related person, i.e. 
the operator for all information about the 
failure. 

a. Current working condition of machine 

(Whether machine is operated prop-
erly).

b.  When troubles are found and what kind 

of operation does machine perform at 
that time?

c.  Development of troubles (Whether 

troubles are becoming severer or occur 
for the 

fi

 rst time.)

d. What kind of trouble did machine have 

before? 

For example: Which parts have been 
repaired or replaced?

e.  What has been done after troubles take 

place and how about the reaction?

f.  Will the trouble reoccur? Does the trou-

ble occur regularly? 

Troubleshooting

SY215C

LC

7-8

3.  Check before starting

Before starting troubleshooting, check the operator's records on operation, maintenance and 
service of the machine. Understand whether related personnel has done wrong in operation, 
maintenance and service. Check for wrong operation and maintenance at the same time. 

Item

Criterion

Remedy

Lubricating oil, coolant

1. Check fuel level and type of fuel
2. Check for impurities in fuel
3. Check hydraulic oil level
4. Check hydraulic oil strainer
5. Check swing drive oil level
6. Check engine oil level (in oil pan)
7. Check coolant level
8. Check dust indicator for clogging
9. Check hydraulic 

fi

 lter

10. Check 

fi

 nal drive oil level

—
—
—
—
—
—
—
—
—
—

Add fuel
Clean, drain
Add oil
Clean, drain
Add oil
Add oil
Add water
Clean or replace
Replace
Add oil

Electrical equipment

1. Check for looseness, corrosion of battery terminal and 
wiring
2. Check for looseness, corrosion of alternator terminal 
and wiring
3. Check for looseness, corrosion of start motor terminal 
and wiring

—
—
—

Tighten or replace

Tighten or replace

Tighten or replace

Hydraulic, 

mechanical 

equipment

1. Check for abnormal noise and smell
2. Check for oil leakage
3. Bleeding air

—
—
—

Repair
Repair
Bleed air

Electrics, electrical equipment

1. Check battery voltage (with engine stopped)
2. Check electrolyte level
3. Check for discolored, burnt, exposed wiring
4. Check for missing wiring clips and hanging wiring
5. Check for wet wires (esp. wet connectors or terminals)
6. Check for blown or corroded fuses
7. Check alternator voltage (with engine speed at middle 
or higher)
8. Check operating sound of battery relay (when start 
switch is turned ON or OFF)

20-30V

—
—
—
—

—

After running for 

several minutes:

27.5~ 29.5V

—

Replace
Add or replace
Replace
Repair
Disconnect con-
nector and dry

Replace
Replace
Replace

Troubleshooting

SY215C

LC

7-9

6.  Operate machine by yourself (trial run)

Confirming that the third item above is 
normal, run startup check on the machine 
to determine the cause of failure. If the 
failure cannot be determined, turn off the 
engine and get more information from the 
operator. 

4.  Perform troubleshooting

Conduct deep analysis and determine the 
cause of trouble according to the symp-
toms of the machine and the information 
displayed on the monitor.

Remark:

 

●

Never disconnect harness and hydraulic 
lines when the engine is running. Oil and 
water under high pressure and high tem-
perature may squirt and cause personal 
injuries. Shut off then engine when discon-
necting the harness and hydraulic lines.

 

●

Failure codes may not indicate machine 
trouble. Temporary electrical failure can oc-
cur in controller memory, such as low bat-
tery output voltage, or open circuit in switch 
or sensor. Therefore, make repeated trials 
to erase the accumulated failure codes 
from the controller memory and confirm 
whether the failure codes are displayed af-
ter repeated trials. That is to say, "reoccur-
rence" of this trouble is possible. 

5.  Find out possible causes

Before making a conclusion, check the 
most possible causes again and try to de-
termine the root causes of troubles. Make 
a feasible repair scheme according to your 
conclusion.

Troubleshooting

SY215C

LC

7-10

7.4  

Connectors

No.

Type

Pin No.

Name of device

Location reference

Layout 

drawing

Cab 

circuit

Engine 

circuit

Sensor, 

solenoid 

circuit

T-401

Terminal

1

Battery relay coil (positive)

M-2

D-1  

T-402

Terminal

1

Battery relay coil (negative)

M-2

D-1

T-403

Terminal

1

Battery relay contact (output)

M-2

D-1

T-404

Terminal

1

Battery relay contact (input)

M-2

D-1

T-417

Terminal

1

Starting motor (B terminal)

J-6

L-3

T-419

Terminal

1

Alternator (B terminal)

K-6

L-5

T-406

Terminal

1

Preheating fuse (21#)

M-2

G-9

T-405

Terminal

1

Preheating fuse (16#)

M-2

G-9

T-408

Terminal

1

Body grounding

M-1

B-1

T-418

Terminal

1

Body grounding

K-6

T-412

Terminal

1

Preheating resistance wire 
terminal

J-7

H-9

T-416

Terminal

1

Starting motor grounding

J-6

L-3

T-407

Terminal

1

Body grounding (battery side)

M-1

B-9

CN-104M

Terminal

1

Body grounding

X-6

T-102

Terminal

1

Body grounding

X-6

K5

R

5

Horn relay

X-6

H-9

K4

R

5

Lamp relay

X-6

I-9

K9

R

5

Top lamp relay

X-6

J-9

R

5

Parking relay

X-6

J-8

KB

—

5

Battery relay

M-2

D-1

K3

R

5

Starting relay

X-6

L-4

K7

—

5

Preheating relay

Y-6

G-9

K10

R

5

Pilot valve relay

X-6

E-1

CN-101F

A

2

Junction connector

W-6

D

12

Intermediate connector

W-6

C-9

CN-314M

D

12

Intermediate connector

R-5

C-9

CN-300F

A

3

Intermediate connector

R-6

D-9

CN-308M

S

6

Intermediate connector

R-6

F-9

CN-133F

D

12

Intermediate connector

R-5

C-5

CN-302M

D

8

Intermediate connector

AB-4

K-7

CN-214F

D

12

Intermediate connector

W-6

D-8

7.4.1  Table of connectors

Troubleshooting

SY215C

LC

7-11

No.

Type

Pin No.

Name of device

Location reference

Layout 

drawing

Cab 

circuit

Engine 

circuit

Sensor, 

solenoid 

circuit

CN-219M

D

12

Intermediate connector

W-6

F-8

CN-1-112

D

3

Intermediate connector

W-6

C-9

CN-1-111

D

8

Intermediate connector

W-6

C-9

CN-7-705

D

12

Monitor panel

P-5

D-9

H

6

Intermediate connector

J-7

K-8

S

6

Intermediate connector

I-7

F-3

CN-489F

A

2

Intermediate connector

X-6

C-8

CN-490F

A

3

Intermediate connector

X-6

C-8

CN-118M

A

2

Washing motor

K-5

K-4

CN-404M

A

2

Platform lamp

E-5

K-2

CN-412M

A

2

Boom lamp (left)

E-7

K-1

CN-411M

A

2

Boom lamp (right)

E-7

K-2

CN-440M

A

2

Hydraulic oil temp sensor

I-7

F-9

CN-405F

S

1

Fuel level sensor

F-6

F-9

A

2

Intermediate connector

W-6

F-8

L

6

Safety relay

X-6

K-7

S

16

Intermediate connector

W-6

I-8

S

16

Intermediate connector

W-6

CN-4465M

DF

3

Main pressure sensor (front)

I-7

F-4

CN-447M

DF

3

Main pressure sensor (rear)

I-7

F-4

CN-428M

DF

3

Arm-in pilot sensor

I-6

F-5

CN-422M

DF

3

Arm out pilot sensor

I-6

F-4

CN-426M

DF

3

Boom-up pilot sensor

I-6

F-5

CN-425M

DF

3

Boom-down pilot sensor

I-6

F-6

CN-424M

DF

3

Bucket-curl pilot sensor

I-6

F-6

CN-427M

DF

3

Bucket-dump pilot sensor

I-6

F-6

CN-423M

DF

3

Swing pilot sensor

I-6

F-7

CN-420M

DF

3

Travel pilot sensor (left)

I-6

F-7

CN-421M

DF

3

Travel pilot sensor (right)

I-6

F-8

CN-448M

S

2

Speed sensor

I-7

F-9

CN-304M

H

8

Top lamp switch

R-5

C-3

CN-301M

H

8

Work lamp switch

R-6

C-2

CN-303M

H

8

Washer switch

R-6

C-2

CN-302M

H

8

Wiper switch

R-6

C-1

Troubleshooting

SY215C

LC

7-12

No.

Type

Pin No.

Name of device

Location reference

Layout 

drawing

Cab 

circuit

Engine 

circuit

Sensor, 

solenoid 

circuit

CN-134M

D

6

Horn switch

R-6

E-3

H

8

Preheating switch

R-5

F-1

CN-116F

S

12

Air conditioner unit

W-6

CN-445F

AMP

2

F. pump solenoid valve 

I-7

F-2

CN-444F

AMP

2

R. pump solenoid valve 

I-7

F-1

CN-435F

AMP

2

Boom priority solenoid valve 2

J-6

F-2

CN-434F

AMP

2

Bucket Con

fl

 uence solenoid 

valve

J-6

F-3

CN-432F

AMP

2

Boom priority solenoid valve 1

J-6

F-3

CN-436F

AMP

2

Pilot solenoid valve

J-6

L-2

CN-431F

AMP

2

Hi/Lo speed travel solenoid 
valve

J-6

F-1

CN-433F

AMP

2

Swing priority solenoid valve

J-6

F-4

W

1

Coolant temperature sensor

J-7

F-8

F-402

W

1

Horn (right)

I-5

K-2

F-401

W

1

Horn (left)

I-5

K-2

CN-448F

AMP

81

Controller

W-6

A-4

CN-487F

AMP

40

Controller

W-6

A-9

CN-460F

S

2

Alternator terminal L/R

K-6

CN-486M

DT

8

Cigarette lighter

P-4

CN-150M

D

8

Intermediate connector

AE-3

CN-102M

HL

7

Radio

W-6

PF021

-

-

Fuse box

X-4

CN-102M

HL

7

Speaker (left)

AE-6

CN-102M

HL

7

Speaker (right)

AD-7

CN-1-150F

DT

8

Front right lamp

AB-6

CN-1-150F

DT

8

Front left lamp

AC-5

CN-1-150F

DT

8

Cab lamp

AE-7

Troubleshooting

SY215C

LC

7-13

Connector type

Description

S

SWP type, Yazaki 

A/AMP

AMP, Japan

D

DT type, Japan

H

Hebi

HL

Hulane Connectors

L

Ling Xing Electronic Equipment

DF

Delphi, U.S.

W

AMP, Japan

Terminal

Round terminal

Troubleshooting

SY215C

LC

7-14

7.4.2 Connector layout

F

E

D

C

B

A

8

7

6

5

1

3

2

4

CN-412M

CN-405F

CN-404M

CN-414M

ZX215-1005033

Troubleshooting

SY215C

LC

7-15

M

L

K

J

I

H

G

T-404

T-408

T-403

F-402

T-407

CN-447M

CN-440M

T-412

T-417

CN-460F

CN-431F

CN-432F

CN-433F

CN-434F

CN-435F

CN-436F

F-401

CN-446M

CN-444F

CN-455F

T-406

T-405

T-401

T-402

KB

T-416

CN-118M

T-C19

T-418

ZX215-1005034

CN-427M

CN-428M

CN-426M

CN-425M

CN-424M

CN-423M

CN-422M

CN-421M

CN-420M

Troubleshooting

SY215C

LC

7-16

N

O

P

Q

R

S

T

4

2

3

1

5

6

7

8

9

CN-460F

CN-7-705

CN-308M

CN-300F

CN-134M

CN-301M

CN-302M

CN-303M

CN-304M

ZX215-1005035

Troubleshooting

SY215C

LC

7-17

T

U

V

W

X

Y

Z

CN-488F

CN-487F

CN-1-111

CN-1-112

CN-219M

CN-214F

CN-104M

K5

K4

K10

K3

K9

K7

PF021

CN-101F

CN-102M

CN-116F

T-102

ZX215-1005036

Troubleshooting

SY215C

LC

7-18

AF

AE

AD

AC

AB

AA

CN-1-110M

CN-1-150F

CN-1-150F

CN-102M

CN-102M

CN-1-150F

4

2

3

1

5

6

7

8

9

CN-150M

ZX215-1005037

Troubleshooting

SY215C

LC

7-25

7.4.6  SWP type connector

               Male (Plug)

7222-7414-40

Female (socket)

7123-7414-40    (No. of pin: 1 ) 

7222-1424-40

7123-1424-40      (No. of pin: 2) 

7222-7464-40

7123-7464-40       (No. of pin: 6) 

7222-7484-40

7123-7484-40      (No. of pin: 8) 

7222-7564-40

7123-7564-40       (No. of pin: 16)