Troubleshooting
Safety, Operation and Maintenance Manual - Aug 2012
6-25
SY115C9/135C/155H Crawler Hydraulic Excavator
Trouble-shoot the electrical system according to the following tables. Contact your Sany distribu-
tor solve the problem.
6.7 Failures of the Electrical System
Failure
Causes
Remedy
Unable to start the en-
gine
●
Battery low
●
Engine start switch internal failure
●
Pilot switch failure
●
Start motor failure
●
Open circuit of wire harness
●
Fuse failure (F1)
●
Short circuit of wire (grounding failure)
●
Alternator internal failure
●
Start relay failure
●
Brake failure
●
Recharge/replace the bat-
tery.
●
Replace
●
Repair/replace
●
Repair/replace
●
Check/repair
●
Replace
●
Check/repair
●
Repair/replace
●
Replace
●
Repair/replace
Rough engine speed
●
Open circuit of wire harness
●
Sensor internal failure
●
Short circuit of wire (grounding failure)
●
Sensor internal failure
●
Check/repair
●
Replace
●
Check/repair
●
Replace
Unable to power off the
machine
●
Battery relay failure
●
Breakdown of surge diode
●
Replace
●
Replace
Auto idle fails.
●
Boom-up signal failure
●
Boom-down signal failure
●
Arm-in signal failure
●
Arm-out signal failure
●
Bucket-dig signal failure
●
Bucket-dump signal failure
●
Swing signal failure
●
Travel signal failure
●
Attachment signal failure
●
Controller failure
●
Check/repair
●
Check/repair
●
Check/repair
●
Check/repair
●
Check/repair
●
Check/repair
●
Check/repair
●
Check/repair
●
Check/repair
●
Replace
Preheating function fails.
●
Preheat fuse failure
●
Preheat relay failure
●
Short circuit of wire (grounding failure)
●
Preheat controller failure
●
Replace
●
Replace
●
Check/repair
●
Replace
All devices fail.
●
Hydraulic lockout control failure
●
Short circuit of wire (grounding failure)
●
Failure of internal coil of pilot lockout valve
●
Repair/replace
●
Check/repair
●
Replace
Boom slow and weak
●
Sensor failure
●
Short circuit of harness (grounding failure)
●
Open circuit of harness
●
Controller failure
●
Replace
●
Check/repair
●
Check/repair
●
Replace
6.7.1 Electrical system troubleshooting table