Page 1638 of 3051

6 CHECK COOLING FAN RELAY-2, 4
Check continuity between cooling fan relays-2, 4 terminals 3 and 4, 3 and 5 under the following conditions.
SEF900Y
OK or NG
OK©GO TO 11.
NG©Replace cooling fan relay.
7 CHECK COOLING FAN OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 219 and cooling fan relay-1 terminal 1. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 9.
NG©GO TO 8.
8 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E76, F13
+Harness for open or short between cooling fan relay-1 and ECM
©Repair open circuit or short to ground or short to power in harness or connectors.
9 CHECK COOLING FAN RELAY-1
Check continuity between cooling fan relay-1 terminals 3 and 5 under the following conditions.
SEF901Y
OK or NG
OK©GO TO 10.
NG©Replace cooling fan relay.
DTC P1217 OVER HEATYD22DDTI
Diagnostic Procedure (Cont'd)
EC-1213
Page 1700 of 3051

15 CHECK HARNESS CONTINUITY BETWEEN GLOW RELAY AND GLOW PLUG FOR OPEN AND SHORT
1. Disconnect glow plug harness connector.
2. Check harness continuity between glow relay terminal 3 and glow plug harness connector. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 16.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
16 CHECK GLOW RELAY
Check continuity between glow relay terminals 3 and 5 under the following conditions.
SEF433Y
OK or NG
OK©GO TO 17.
NG©Replace glow relay.
17 CHECK GLOW PLUG
1. Remove glow plug connecting plate.
2. Check glow plug resistance.
SEF434Y
NOTE:
+Do not bump glow plug heating element. If it is bumped, replace glow plug with a new one.
+If glow plug is dropped from a height of 10 cm (3.94 in) or higher, replace with a new one.
+If glow plug installation hole is contaminated with carbon, remove it with a reamer or suitable tool.
+Hand-tighten glow plug by turning it two or three times, then tighten using a tool to specified torque.
: 17.7 - 22.5 N´m (1.8 - 2.3 kg-m, 13 - 16 ft-lb)
OK or NG
OK©GO TO 18.
NG©Replace glow plug.
GLOW CONTROL SYSTEMYD22DDTI
Diagnostic Procedure (Cont'd)
EC-1275
Page 1702 of 3051

DescriptionNLEC0764SYSTEM DESCRIPTIONNLEC0764S01
Sensor Input Signal to ECM ECM Function Actuator
Electronic controlled fuel injection pump Fuel injection signal
EGR volume con-
trolEGR volume control
valve Crankshaft position sensor (TDC) Engine speed
Vehicle speed sensor Vehicle speed
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Accelerator position sensor Accelerator position
Mass air flow sensor Amount of intake air
Air conditioner switch Air conditioner operation
Electrical load Electrical load signal
This system controls flow rate of EGR led from exhaust manifold
to intake manifold. The opening of the EGR by-pass passage in the
EGR volume control valve changes to control the flow rate. A
built-in step motor moves the valve in steps corresponding to the
ECM output pulses. The opening of the valve varies for optimum
engine control. The optimum value stored in the ECM is determined
by considering various engine conditions.
The EGR volume control valve remains close under the following
conditions.
+Engine stopped
+Engine starting
+Low engine coolant temperature
+Excessively high engine coolant temperature
+High engine speed
+Wide open throttle
SEF908Y
SEF411Y
COMPONENT DESCRIPTIONNLEC0764S02EGR Volume Control ValveNLEC0764S0201The EGR volume control valve uses a step motor to control the flow
rate of EGR from exhaust manifold. This motor has four winding
phases. It operates according to the output pulse signal of the
ECM. Two windings are turned ON and OFF in sequence. Each
time an ON pulse is issued, the valve opens or closes, changing
the flow rate. When no change in the flow rate is needed, the ECM
does not issue the pulse signal. A certain voltage signal is issued
so that the valve remains at that particular opening.
EGR VOLUME CONTROL SYSTEMYD22DDTI
Description
EC-1277
Page 1703 of 3051

CONSULT-II Reference Value in Data Monitor
Mode
NLEC0765Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
EGR VOL CON/V+Engine: After warming up
+Air conditioner switch: ªOFFº
+Shift lever: Neutral position
+No-loadAfter one minute at idle More than 10 step
Revving engine up to 3,200 rpm 0 step
ECM Terminals and Reference ValueNLEC0766Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA(DC Voltage)
337
338
350
351W/L
PU/W
GY
OR/BEGR volume control valve[Engine is running]
+Warm-up condition
+Idle speed0.1 - 14V
(Voltage signals of each
ECM terminals differ
according to the control
position of EGR volume
control valve.)
EGR VOLUME CONTROL SYSTEMYD22DDTI
CONSULT-II Reference Value in Data Monitor Mode
EC-1278
Page 1710 of 3051

DescriptionNLEC1266SYSTEM DESCRIPTIONNLEC1266S01
Sensor Input Signal to ECMECM Func-
tionActuator
Ignition switch Start signal
Swirl con-
trol valve
controlSwirl control valve control solenoid
valve
¯Vacuum signal
Swirl control valve actuator
¯
Swirl control valve Crankshaft position sensor (TDC) Engine speed
Engine coolant temperature sensor Engine coolant temperature
This system has a swirl control valve in the intake manifold.
Under normal driving conditions, the swirl control valve closes,
generating a strong swirl in the combustion chamber. This pro-
motes the mixing of fuel and air for stable combustion.
Under high-load conditions, the swirl control valve opens. By
obtaining a volume of air for an increase in fuel, combustion that
does not easily emit black smoke is achieved.
The solenoid valve controls swirl control valve's shut/open condi-
tion. This solenoid valve is operated by the ECM.
Engine speed Engine coolant temperatureSwirl control valve control sole-
noid valveSwirl control valve
Less than 2,400 rpm*Less than 20ÉC (68ÉF) OFF Open
More than 20ÉC (68ÉF) ON Closed
More than 2,400 rpmLess than 20ÉC (68ÉF) OFF Open
More than 20ÉC (68ÉF) OFF Open
*: Except in idle condition and high-load condition
SEF872Z
SEF876Z
COMPONENT DESCRIPTIONNLEC1266S02Swirl Control Valve Control Solenoid ValveNLEC1266S0201The swirl control valve control solenoid valve responds to signals
from the ECM. When the ECM sends an ON (ground) signal, the
solenoid valve is bypassed to apply vacuum pump vacuum to the
swirl control valve actuator. This operation closes the swirl control
valve. When the ECM sends an OFF signal, the vacuum signal is
cut and the swirl control valve opens.
SWIRL CONTROL VALVE CONTROL SOLENOID VALVEYD22DDTI
Description
EC-1285
Page 1717 of 3051
8 CHECK SWIRL CONTROL VALVE CONTROL SOLENOID VALVE
1. Apply 12V direct current between swirl control valve control solenoid valve terminals.
2. Check air passage continuity of swirl control valve control solenoid valve under the following conditions.
SEF335X
OK or NG
OK©GO TO 9.
NG©Replace swirl control valve control solenoid valve.
9 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-1135.
©INSPECTION END
SWIRL CONTROL VALVE CONTROL SOLENOID VALVEYD22DDTI
Diagnostic Procedure (Cont'd)
EC-1292
Page 1720 of 3051

Diagnostic ProcedureNLEC0770
1 CHECK START SIGNAL OVERALL FUNCTION
With CONSULT-II
1. Turn ignition switch ªONº.
2. Check ªSTART SIGNALº in ªDATA MONITORº mode with CONSULT-II under the following conditions.
SEF604X
Without CONSULT-II
Check voltage between ECM terminal 422 and ground under the following conditions.
SEF909Y
OK or NG
OK©INSPECTION END
NG©GO TO 2.
2 CHECK START SIGNAL INPUT SIGNAL CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector and ignition switch harness connector.
3. Check harness continuity between ECM terminal 422 and ignition switch terminal 6. Refer to Wiring Diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 4.
NG©GO TO 3.
3 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors M49, F23 (where fitted)
+Harness connectors M71, F45 (where fitted)
+10A fuse
+Fuse block (J/B) connectors M2, E109
+Harness for open or short between ECM and ignition switch
©Repair open circuit or short to ground or short to power in harness or connectors.
START SIGNALYD22DDTI
Diagnostic Procedure
EC-1295
Page 1726 of 3051
Wiring DiagramNLEC0786MODELS WITH ECM IN ENGINE COMPARTMENTNLEC0786S01
YEC735
AIR CONDITIONER CONTROLYD22DDTI
Wiring Diagram
EC-1301