Page 158 of 192

EGRC-Solenoid Valve A, B and Throttle Control
Solenoid Valve
SYSTEM DESCRIPTION
Camshaft position sensor (TDC)cEngine speed
ECM
(ECCS-D
control
module)cEGRC-solenoid valve A
Accelerator position sensorcAccelerator positioncEGRC-solenoid valve B
Engine coolant temperature sensorcEngine coolant temperaturecThrottle control solenoid valve
Ignition switchcStart signal
Mass air ¯ow sensor
cAmount of intake air
The ECM receives signals sent from the engine coolant tempera-
ture sensor, crankshaft position sensor (TDC), ignition switch, mass
air ¯ow sensor and accelerator position sensor to determine engine
speed and operating conditions. Based on these signals, the ECM
controls EGR control solenoid valve (A and B) operation and
throttle control solenoid valve operation.
Engine coolant
temperature
ÉC (ÉF)LoadEGRC-solenoid valve
Throttle control
solenoid valveEGR valveThrottle control
valveAmount of EGR
gas
AB
Below 70 (158) AnyOFF
(Closed)OFF
(Closed)OFF
(Closed)Fully closed Fully open Ð
Above 70 (158)Low loadON
(Open)ON
(Open)ON
(Open)Fully open Closed Large
Medium load-1ON
(Open)ON
(Open)OFF
(Closed)Fully open Fully open Medium
Medium load-2ON
(Open)OFF
(Closed)OFF
(Closed)Half open Fully open Small
High loadOFF
(Closed)OFF
(Closed)OFF
(Closed)Fully closed Fully open Ð
COMPONENT DESCRIPTION
The EGRC-solenoid valves A and B control vacuum pressure act-
ing on the EGR valve. The EGR control valve will then be fully
opened, half-opened or fully closed, as required.
The throttle control solenoid valve controls vacuum pressure acting
on the throttle chamber. Thus, intake air passages are opened or
closed in relation to exhaust gas and intake air. Utilizing the rela-
tionship between exhaust gas pressure and intake air pressure
control, the amount of EGR (exhaust gas recirculated) is regulated
in three stages Ð large, medium, small.
SEF784V
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EC-156 
         
        
        
     
        
        Page 180 of 192

Charge Air Cooler Fan Control
SYSTEM DESCRIPTION
Crankshaft position sensor (TDC)cEngine speed
ECM
cCharge air cooler fan relayCharge air temperature sensorcCharge air temperature
Ignition switch
cStart signal
The ECM controls the charge air cooler fan operation corresponding to the engine speed, the charge air tem-
perature and the start signal. The control system has 2-step control [ON/OFF]. The ECM does not directly drive
the charge air cooler fan. It controls the ON/OFF charge air cooler fan relay, which in turn controls the charge
air cooler fan.
When the charge air temperature is above 67ÉC (153ÉF) and engine speed is more than 1,600 rpm, the charge
air cooler fan operates.
CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
I/C FAN RLY+When charge air cooler fan is stopped. OFF
+When charge air cooler fan operates. ON
ECM TERMINALS AND REFERENCE VALUE
Remarks: Speci®cation data are reference values and are measured between each terminal andV43(ECCS
ground) with a voltmeter.
TER-
MINAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse
Signal)
8 G/ORCharge air cooler fan
relayEngine is running.
Charge air cooler fan is not operating.BATTERY VOLTAGE
(11 - 14V)
Engine is running.
Charge air cooler fan is operating.0-1V
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EC-178 
         
        
        
     
        
        Page 191 of 192

General Speci®cations
Unit: rpm
Engine RD28ETi
Idle speed 775 25
Maximum engine speed 5,400
Injection pump numbers
Engine Part numberPump assembly
number
RD28ETi 16700 VB300 104721-2000
Injection Nozzle
INSPECTION AND ADJUSTMENT
Injection nozzle assembly
Unit: kPa (bar, kg/cm2, psi)
Initial injection pressure
Used 14,220 (142.2, 145, 2,062)
New14,711 - 15,495 (147.1 - 155.0,
150 - 158, 2,133 - 2,247)
Adjusting shims
Thickness mm (in) Parts No.
0.50 (0.0197) 16613-V0700
0.54 (0.0213) 16613-V0702
0.58 (0.0228) 16613-V0704
0.62 (0.0244) 16613-V0706
0.66 (0.0260) 16613-V0708
0.70 (0.0276) 16613-V0710
0.74 (0.0291) 16613-V0712
0.78 (0.0307) 16613-V0714
0.82 (0.0323) 16613-V0716
0.86 (0.0339) 16613-V0718
0.90 (0.0354) 16613-V0720
0.94 (0.0370) 16613-V0722
0.98 (0.0386) 16613-V0724
1.00 (0.0394) 16613-V0760
Inspection and Adjustment
Plunger lift mm (in)0.92 0.04 (0.0362 0.0016)
(at 9.75É ATDC)
CAMSHAFT POSITION SENSOR (PUMP)
Resistance [at 25ÉC (77ÉF)]W1,360 - 1,840
ENGINE COOLANT TEMPERATURE
SENSOR
Temperature ÉC (ÉF) Resistance kW
20 (68) 2.1 - 2.9
50 (122) 0.68 - 1.00
90 (194) 0.236 - 0.260
CONTROL SLEEVE POSITION SENSOR
Resistance [at 23ÉC (73ÉF)]W5.9
SERVICE DATA AND SPECIFICATIONS (SDS)
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ADJUSTMENT RESISTOR
Resistance [at 25ÉC (77ÉF)] kW0.2 - 15.0
INJECTION TIMING CONTROL VALVE
Resistance [at 20ÉC (68ÉF)]WApproximately 11
ELECTRIC GOVERNOR
Resistance [at 23ÉC (73ÉF)]W0.68
CRANKSHAFT POSITION SENSOR (TDC)
Resistance [at 25ÉC (77ÉF)] kWApproximately 0.8 - 1.2
GLOW PLUG
Resistance [at 25ÉC (77ÉF)]W0.8
ACCELERATOR POSITION SENSOR
Throttle valve conditionsResistance kW
[at 25ÉC (77ÉF)]
Completely closed Approximately 0.5
Partially open 0.5 - 4
Completely open Approximately 4
FUEL TEMPERATURE SENSOR
Temperature ÉC (ÉF) Resistance kW
þ20 (þ4) 13.67 - 16.37
20 (68) 2.306 - 2.568
60 (140) 0.538 - 0.624
80 (176) 0.289 - 0.344
SERVICE DATA AND SPECIFICATIONS (SDS)
Inspection and Adjustment (Cont'd)
EC-190