Content .. 15 16 17 18 ..

Hyundai Excavator R450LC-7. Service and repair manual - page 17

5-23

2. OPERATING PRINCIPLE

STRUCTURE

P Pilot oil supply line(Pilot pressure)
T

Return to tank

A Secondary pressure to flow regulator at hydraulic pump

AT H MODE
Pressure line is blocked and A oil returns to tank.

AT S MODE
Secondary pressure enters into A.

Sleeve

Spring

Spool

O-ring

Solenoid valve

Connector

5-22(1) 210-7

5-22(2) 210-7

5-22A (210-7)

5-22B (210-7)

5-22C (210-7)

5-24

3. EPPR VALVE CHECK PROCEDURE

CHECK ELECTRIC VALUE AT EPPR
VALVE

Start engine.

Set S-mode and cancel auto decel mode.

Position the accel dial at 10.

If tachometer show approx 1850

50rpm,

disconnect one wire harness from EPPR
valve.

Install multimeter as figure.

Check electric current at bucket circuit
relief position.

HECK PRESSURE AT EPPR VALVE

Remove plug and connect pressure
gauge as figure.

Gauge capacity : 0 to 40-50kgf/cm

(0 to 580-725psi)

Start engine.

Set S-mode and cancel auto decel mode.

Position the accel dial at 10.

If tachometer show approx 1850

50rpm,

check pressure at relief position of bucket
circuit by operating bucket control lever.

If pressure is not correct, adjust it.

After adjust, test the machine.

CN-75

Multimeter

EPPR VALVE

CN-75

Supply line, pilot press

Pressure adjusting
screw
locknut

(1)

(2)

(3)

(4)

(5)

(6)

(1)

(2)

(3)

(4)

(5)

(6)

(7)

Spec : 200~450mA

Spec : 2~25kgf/cm

(30~350psi)

5-23(1) 210-7

5-23(2) 210-7

5-25

GROUP 12 MONITORING SYSTEM

1. OUTLINE

Monitoring system consists of the monitor part and switch part.
The monitor part gives warnings when any abnormality occurs in the machine and informs the
condition of the machine.
Various select switches are built into the monitor panel, which act as the control portion of the machine
control system.

2. CLUSTER

MONITOR PANEL

5-26

CLUSTER CHECK PROCEDURE

Start key : ON

Check monitor initial 5 seconds

All lamps light up.
Buzzer sound.

Check monitor after 5 seconds : Indicate cluster version and machine condition

Cluster program version : CL : 1.4 Indicates program version 1.4 for 2 seconds.
Tachometer : 0rpm
Fuel gauge : All light up below appropriate level
Hydraulic temperature : All light up below appropriate level
Engine coolant temperature gauge : All light up below appropriate level
Warning lamp
During start key ON the engine oil pressure lamp and battery charging lamp go on, but it is not
abnormal.
When engine coolant temperature below 30

。

C, the warming up lamp lights up.

Indicating lamp state

Work mode selection : General work
Power mode selection : S mode
User mode selection : No LED ON
Auto decel LED : ON
Travel speed pilot lamp : Low(Turtle)

tart of engine

Check machine condition

Tachometer indicates at present rpm
Gauge and warning lamp : Indicate at present condition.
When normal condition : All warning lamp OFF
Work mode selection : General work
Power mode selection : S mode
User mode selection : No LED ON
Auto decel LED : ON
Travel speed pilot lamp : Low(Turtle)

When warming up operation

Warming up lamp : ON
10 seconds after engine started, engine speed increases to1000rpm(Auto decel LED : ON)
Others same as above

①.

When abnormal condition

The lamp lights up and the buzzer sounds.
If B

UZZER STOP switch is pressed, buzzer sound is canceled but the lamp light up until

normal condition.

(1)

①

②

a.
b.

a.
b.
c.
d.
e.
f.

※

(

③

①

②

③

a.
b.

※

c.
d.
e.
f.
g.

a.
b.

※

a.
b.

a.
b.
c.
d.
e.

5-27

3. CLUSTER CONNECTOR

Cluster

21075MS16

5-29

This lamp blinks and the buzzer sounds when the level of fuel
is below 68

ℓ

(18U.S. gal).

Fill the fuel immediately when the lamp blinks.

Fuel low level warning lamp

(1)

(2)

This lamp blinks and the buzzer sounds when the temperature
of coolant is over the normal temperature 105

。

(

221

。

F) .

Check the cooling system when the lamp blinks.

Hydraulic oil temperature warning lamp

(1)

(2)

This warning lamp operates and the buzzer sounds when the
temperature of hydraulic oil is over 110

。

(

221

。

F).

Check the hydraulic oil level when the lamp blinks.

Check for debris between oil cooler and radiator.

Overheat warning lamp

(1)

(2)

(3)

This lamp blinks and the buzzer sounds after starting the
engine because of the low oil pressure.

If the lamp blinks during engine operation, shut OFF engine
immediately. Check oil level.

Engine oil pressure warning lamp

(1)

(2)

This lamp blinks and the buzzer sounds when the filter of air
cleaner is clogged.

Check the filter and clean or replace it.

Air cleaner warning lamp

(1)

(2)

21073CD04A

21073CD05A

21073CD06A

21073CD07

21073CD08

5-30

Communication problem between CPU controller and cluster
makes the lamp blink and the buzzer sounds.

Check if any fuse for cpu burnt off.

Check the communication line between CPU controller and
cluster.

(1)

(2)

(3)

CPU controller check warming lamp

10)

This lamp blinks and the buzzer sounds when the starting
switch is ON, it is turned OFF after starting the engine.

Check the battery charging circuit when this lamp blinks during
engine operation.

Battery charging warning lamp

(1)

(2)

11)

When the machine is overload, the overload warning lamp
blinks during the overload switch ON.

(1)

Overload warning lamp(Option)

12)

This lamp blinks and buzzer sounds when the communication
between CPU controller and ECM on the engine is abnormal
or if any fault code received from ECM.
Check the communication line between them. If the
commumication line is OK, then check the fault code on the
cluster.

①

②

ngine check lamp

13)

21073CD10

21073CD13

21073CD15

21073CD09

The lamp will be ON when pushing power max switch on the
LH RCV lever.

(1)

Power max pilot lamp

14)

21073CD11

5-31

Operating auto decel or one touch decel makes the lamp ON.

The lamp will be ON when pushing one touch decel switch on
the LH RCV lever.

(1)

(2)

Decel pilot lamp

15)

This lamp is turned ON when the coolant temperature is below
30

。

(

。

F).

The automatic warming up is cancelled when the engine
coolant temperature is above 30

。

C, or when 10 minutes have

passed since starting.

Warming up pilot lamp

(1)

(2)

16)

This lamp is turned ON when the preheating function is
actuated in cold weather.

Start the engine as this lamp is OFF.

Preheat pilot lamp

(1)

(2)

17)

This switch is to select the machine operation mode, which
shifts from general operation mode to heavy operation mode
and breaker mode in a raw by pressing the switch.

: Heavy duty work mode

: General work mode

: Breaker operation mode

efer to the page 5-4 for details.

Work mode switch

(1)

※

18)

21073CD17

21073CD18

21073CD12

21073CD20

User mode switch

19)

This switch is to select the memory sets, at which you can
change the engine and pump power and memorize it into MI
and MI mode for your preference.
Refer to the page 5-5 for details.

(1)

※

21073CD21

5-32

This switch is used to actuate or cancel the auto deceleration
function. When actuated the engine speed is lowered
automatically when all control levers and pedals are at neutral
position to save the fuel.

Light ON : Auto deceleration function is selected.

Light OFF : Auto deceleration function is cancelled so that the

engine speed increased to previous setting value.

Operating the auto deceleration function makes the decel
indicating lamp on the LCD panel ON.

uto deceleration switch

(1)

(2)

20)

The lamp of selected mode is turned ON by pressing the
switch( ).

H : High power work.

S : Standard power work.

ower mode switch

(1)

21)

This switch is to control the travel speed which is changed to
high speed(Rabbit mark) by pressing the switch and low
speed(Turtle mark) by pressing it again.

Travel speed control switch

(1)

22)

When the starting switch is turned ON first, normally the alarm
buzzer sounds for 2 seconds during lamp check operation.

The red lamp lights ON and the buzzer sounds when the
machine has a problem.
In this case, press this switch and buzzer stops, but the red
lamp lights until the problem is cleared.

Buzzer stop switch

(1)

(2)

23)

21073CD22

21073CD23

21073CD24

21073CD25

5-33

Select switch

24)

5-36

DESCRIPTION OF MONITORING DISPLAY

Group

Display

Name

Description

2250 rpm

TIME 12 : 30

EP : 10bar

45 : C1.0

P1 : 100bar

(Option)

P2 : 200bar

(Option)

P3 : 30bar

(Option)

b: 24.8V

Po : 2.5V

dL : 3.8V

Hd : 50

。

Ct : 85

。

AP : 100

It displays current engine speed detected by engine speed
sensor from 500 to 3000rpm.
Range : 500~3000rpm by 10rpm

It displays current time(12 is hour and 30 is minute)
Range : Hour(1~12), minute(00~59)

It shows that pump power shift pressure of EPPR valve being
controlled by the CPU controller is 10bar.
Range : 00~50bar by 1bar

It shows that machine model(R450LC-7) and the program
version of the CPU controller is 1.0.
Version display range : 0.0~9.9 by 0.1

It displays front pump pressure of 100bar which is detected by
pressure sensor.
Range : 000~500bar by 10bar

It displays rear pump pressure of 200bar which is detected by
pressure sensor.
Range : 000~500bar by 10bar

It displays pilot pump pressure of 30bar which is detected by
pressure sensor.
Range : 00~50bar by 1bar

It shows that battery power of 24.8V is supplied into CPU controller.
Range : 00.0~48.0V by 0.1V

It shows that throttle command signal voltage is 2.5V.
Range : 0.0~5.0V by 0.1V

It shows that accel dial signal voltage is 3.8V.
Range : 0.0~5.0V by 0.1V

It shows that hydraulic oil temperature detected by temperature
sensor is 50

。

Range : 0~150

。

C by 1

。

It shows that coolant oil temperature received from ECM is
50

。

Range : 0~150

。

C by 1

。

It shows that ambient pressure recived from ECM is 120kpa
Range : 0~125kpa by 1kpa

Engine speed

Time

Power shift
pressure of
EPPR valve

Model and CPU
program version

Front pump
pressure

Rear pump
pressure

Pilot pump
pressure

Battery voltage

Potentiometer
voltage

Accel dial
voltage

Hydraulic oil
temperature

Coolant
temperature

Ambient
pressure

roup 1

Group 0

5-37

Group

Display

Name

Description

CHECK

Er : 03

TIME

Er : 03

TIME

Er : 00

PP : on or oFF

dP : on or oFF

Pb : on or oFF

oP : on or oFF

od : on or oFF

br : on or oFF

PH : on or oFF

It shows that current error of 03(Short circuit in pump EPPR valve
system) is diagnosed by self diagnosis system in the CPU controller.
If more than 2 errors, when pressing or switch, other
error codes show.
Range : 00~999

It shows recorded error code of 03 which is diagnosed before.
If more than 2 error codes, when pressing or switch,
other error codes show.
Range : 00~58

It shows all recorded error codes are removed in the CPU
controller memory.

Current error

Recorded error

Recorded error
deletion

Pump prolix
switch

Auto decel
pressure switch

Power
boost switch

Travel oil
pressure switch

One touch
decel switch

Travel alarm
switch

Preheat switch

Group 3

Group 2

Shows that pump prolix switch is turned on(At
emergency position).
Shows that pump prolix switch is turned off(At normal
position).

Shows that auto decel pressure switch is pressed on
(No operation of control lever).
Shows that auto decel pressure switch is released off
(Operation of control lever).

Shows that power boost switch is pressed on
(Activated).
Shows that power boost switch is released off
(Canceled).

Shows that travel oil pressure switch is pressed on
(No operation of travel control lever).
Shows that travel oil pressure switch is released off
(Operation of travel control lever).

Shows that one touch decel switch is pressed.
Shows that one touch decel switch is released.

Shows that travel alarm function is selected.
Shows that travel alarm function is canceled.

Shows that preheat switch is pressed.
Shows that preheat switch is released.

PP : on

PP : oFF

dP : on

dP : oFF

Pb : on

Pb : oFF

oP : on

oP : oFF

od : on
od : oFF

br : on
br : oFF

PH : on
PH : oFF

5-38

Group

Display

Name

Description

Ho : on or oFF

nr : on or oFF

ts : on or oFF

PS : on or oFF

bs : on or oFF

Ru : on or oFF

FS : on or oFF

PR : on or oFF

Shows that hourmeter is activated by CPU controller.
Shows that hourmeter is turned off.

Shows that neutral relay for anti-restarting function is
activated(Engine start is possible).
Shows that neutral relay is turned off to disable the
engine restart.

Shows that travel speed solenoid is activated
(High speed).
Shows that travel speed solenoid is released
(Low speed).

Shows that power boost solenoid is activated to
maximize the power(Power up).
Shows that power boost solenoid is turned off(Cancel
the power boost function).

Shows that boom priority solenoid is activated.
Shows that boom priority solenoid is released.

Shows that travel buzzer is activated.
Shows that travel buzzer is canceled.

Shows that max flow cut off solenoid is activated.
Shows that max flow cut off solenoid is released.

Shows that preheat relay is activated.
Shows that preheat relay is released.

Hourmeter

Neutral relay
(Anti-restart
relay)

Travel speed
solenoid

Power boost
solenoid

Boom priority
solenoid

Travel alarm

Max flow cut off
solenoid

Preheat relay

Group 4

Ho : on
Ho : oFF

nr : on

nr : oFF

ts : on

ts : oFF

PS : on

PS : oFF

bs : on
bs : oFF

Ru : on
Ru :oFF

FS : on
FS : oFF

PR : on
PR : oFF

Content .. 15 16 17 18 ..