Page 305 of 1226

jA
CHECK COMPONENTS
(Glow relay, Glow plug).
Refer to ``COMPONENT INSPECTION'',
EC-155.
OK
cNG
Replace malfunctioning
component(s).
Disconnect and reconnect harness connec-
tors in the circuit. Then retest.
Trouble is not ®xed.
Check ECM pin terminals for damage and
check the connection of ECM harness con-
nector. Reconnect ECM harness connector
and retest.
INSPECTION END
SYSTEM OPERATION CHECK
Set voltmeter between glow plug and engine body.
1. Quick-glow (Pre-glow) system
a. Turn ignition switch ``ON''.
b. Read voltage.
Voltage:
Battery voltage for about 20* seconds
* Engine coolant temperature is lower than 90ÉC
(194ÉF). [It is lower than 70ÉC (158ÉF) after
warm-up.]
* Repeating ignition switch ``ON'' and ``OFF'' may
change the time.
2. Quick-glow (Cranking) system
a. Disconnect ``S'' terminal for starter motor to prevent engine
from cranking.
b. Read voltage when ignition switch is turned to ``START''.
Voltage:
Battery voltage*
* For about 20 seconds after returning ignition
switch to ``ON''.
SEF700V
SEF780V
.
.
.
.
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
Glow Control System (Cont'd)
EC-154
Page 306 of 1226

3. After-glow system
a. Connect ``S'' terminal to starter motor.
b. Start engine and read voltage.
Voltage:
Battery voltage for 5* minutes
* Engine coolant temperature is lower than 50ÉC
(122ÉF).
COMPONENT INSPECTION
Glow relay
1. Check relay for coil continuity.
Continuity should exist.
2. Check relay for proper operation.
Coil voltage Continuity Contact point
0V No OFF
12V Yes ON
Glow plug
1. Remove glow plug connecting plate.
2. Check each glow plug for continuity.
Continuity should exist:
Approximately 0.8W[at 25ÉC (77ÉF)]
+If NG, replace glow plug.
3. Install glow plug connecting plate securely.
+Do not bump glow plug heating element. If it is bumped,
replace glow plug with new one. (If glow plug is dropped
from a height of 10 cm (3.94 in), replace with new one.)
+If glow plug installation hole is contaminated with carbon,
remove using a reamer or suitable tool.
+Hand-tighten glow plug by turning it two to three times,
then tighten using a tool to speci®ed torque.
:15-20Nzm (1.5 - 2.0 kg-m, 11 - 14 ft-lb)
SEF781V
SEC564B
SEF701V
SEC565B
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
Glow Control System (Cont'd)
EC-155
Page 307 of 1226

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 308 of 1226

CONSULT REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Speci®cation data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
EGRC SOL/V A+Engine: After warming up
+Air conditioner switch: ``OFF''
+Shift lever: ``N''
+No-loadIdle ON
Revving engine from idle to 3,750
rpmOFF
EGRC SOL/V B+Engine: After warming up
+Air conditioner switch: ``OFF''
+Shift lever: ``N''
+No-loadIdle ON
Revving engine from idle to 2,600
rpmOFF
THROT RLY+Engine: After warming up
+Air conditioner switch: ``OFF''
+Shift lever: ``N''
+No-loadIdle ON
Revving engine from idle to 2,500
rpmOFF
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)
1WThrottle control solenoid
valveEngine is running.
(Warm-up condition)
Idle speedApproximately 0.4V
Engine is running.
(Warm-up condition)
Revving engine from idle to 2,500 rpmBATTERY VOLTAGE
(11 - 14V)
103 L/Y EGRC-solenoid valve AEngine is running.
(Warm-up condition)
Idle speed0-1V
Engine is running.
(Warm-up condition)
Revving engine from idle up to 3,750 rpm.BATTERY VOLTAGE
(11 - 14V)
109 BR/Y EGRC-solenoid valve BEngine is running.
(Warm-up condition)
Idle speed0-1V
Engine is running.
(Warm-up condition)
Revving engine from idle up to 2,600 rpm.BATTERY VOLTAGE
(11 - 14V)
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EGRC-Solenoid Valve A, B and Throttle Control
Solenoid Valve (Cont'd)
EC-157
Page 309 of 1226
TEC442
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EGRC-Solenoid Valve A, B and Throttle Control
Solenoid Valve (Cont'd)
EC-158
Page 310 of 1226

DIAGNOSTIC PROCEDURE
INSPECTION START
CHECK OVERALL FUNCTION.
1. Start engine and warm it up to normal
operating temperature.
2. Perform diagnostic test mode II (Self-
diagnostic results).
Make sure that diagnostic trouble code
No. 55 is displayed.
3. Make sure that EGR valve spring
moves up and down (Use your ®nger)
under the following conditions.
At idle:
Spring moves up and down.
Revving engine from idle to 3,800
rpm:
Spring does not move.
4. Make sure that throttle control valve rod
moves up and down under the following
conditions.
At idle:
Rod moves up and down.
Revving engine from idle to 2,500
rpm:
Rod does not move.
NG
cOK
INSPECTION END
CHECK VACUUM SOURCES TO EGR
VALVE AND THROTTLE CONTROL
VALVE.
1. Disconnect vacuum hose to EGR valve.
2. Make sure that vacuum exists under
the following conditions.
At idle:
Vacuum should exist.
Revving engine from idle to 3,800
rpm:
Vacuum should not exist.
3. Disconnect vacuum hose to throttle
control valve.
4. Make sure that vacuum exists under
the following conditions.
At idle:
Vacuum should exist.
Revving engine from idle to 2,500
rpm:
Vacuum should not exist.
NG
cOK
CHECK COMPONENTS
(EGR valve and throttle
control valve).
(See page EC-162.)
NG
Replace malfunctioning
component(s).
jA
SEF702V
SEF703V
SEF704V
SEF705V
.
.
.
.
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EGRC-Solenoid Valve A, B and Throttle Control
Solenoid Valve (Cont'd)
EC-159
Page 311 of 1226

jA
CHECK CONTROL FUNCTION.
1. Stop engine.
2. Turn ignition switch ``ON''.
3. Turn EGRC-solenoid valve A, B
and throttle control solenoid
valve ``ON'' and ``OFF'' in
``ACTIVE TEST'' mode with
CONSULT and check operating
sound.
--------------------------------------------------------------------------------------------------------------------------------------OR--------------------------------------------------------------------------------------------------------------------------------------
1. Check voltage between ECM
terminal
103and ground under
the following conditions.
Voltage:
At idle
0-1V
Revving engine from idle to
3,800 rpm
Battery voltage
2. Check voltage between ECM
terminal
109and ground under
the following conditions.
Voltage:
At idle
0-1V
Revving engine from idle to
2,600 rpm
Battery voltage
3. Check voltage between ECM
terminal
V1and ground under
the following conditions.
Voltage:
At idle
0-1V
Revving engine from idle to
2,500 rpm
Battery voltage
NG
cOK
CHECK VACUUM HOSE.
Check vacuum hose for
clogging, cracks or
improper connection.
jB
SEF682S
SEF683S
SEF816F
.
.
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EGRC-Solenoid Valve A, B and Throttle Control
Solenoid Valve (Cont'd)
EC-160
Page 312 of 1226

jB
CHECK POWER SUPPLY.
1. Turn ignition switch ``OFF''.
2. Disconnect EGRC-solenoid valve A, B
and throttle control solenoid valve har-
ness connector.
3. Turn ignition switch ``ON''.
4. Check voltage between terminal
V1
and ground with CONSULT or tester.
Voltage: Battery voltage
OK
cNG
Check the following.
+Harness connectors
M21,E127
+10A fuse
+Harness for open or
short between EGRC-
solenoid valve A, B and
fuse
+Harness for open or
short between throttle
control solenoid valve
and fuse
If NG, repair harness or
connectors.
CHECK OUTPUT SIGNAL CIRCUIT.
1. Turn ignition switch ``OFF''.
2. Disconnect ECM harness connector.
3. Check harness continuity between
ECM terminal
V1and terminalV2,
ECM terminal
103and terminalV2,
ECM terminal
109and terminalV2.
Continuity should exist.
If OK, check harness for short to
ground and short to power.
OK
cNG
Check the following.
+Harness connectors
E127,M21
+Harness connectors
M50,F5
+Harness for open or
short between EGRC-
solenoid valve A, B and
ECM
+Harness for open or
short between throttle
control solenoid valve
and ECM
If NG, repair open circuit or
short to ground or short to
power in harness or con-
nectors.
CHECK COMPONENTS
(EGRC-solenoid valve A, B and throttle
control solenoid valve).
Refer to ``COMPONENT INSPECTION''
on next page.
OK
cNG
Replace malfunctioning
component(s).
Disconnect and reconnect harness connec-
tors in the circuit. Then retest.
Trouble is not ®xed.
Check ECM pin terminals for damage or
the connection of ECM harness connector.
Reconnect ECM harness connector and
retest.
INSPECTION END
SEF706V
SEF782V
SEF783V
.
.
.
.
.
.
TROUBLE DIAGNOSES FOR NON-DETECTABLE ITEMS
EGRC-Solenoid Valve A, B and Throttle Control
Solenoid Valve (Cont'd)
EC-161