Page 1537 of 2898

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 SYSTEMYD
Diagnostic Procedure (Cont'd)
EC-813
Page 1538 of 2898
18 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-665.
©INSPECTION END
GLOW CONTROL SYSTEMYD
Diagnostic Procedure (Cont'd)
EC-814
Page 1539 of 2898

DescriptionNJEC0764SYSTEM DESCRIPTIONNJEC0764S01
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 DESCRIPTIONNJEC0764S02EGR Volume Control ValveNJEC0764S0201The 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 SYSTEMYD
Description
EC-815
Page 1540 of 2898

CONSULT-II Reference Value in Data Monitor
Mode
NJEC0765Specification 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 ValueNJEC0766Specification 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 SYSTEMYD
CONSULT-II Reference Value in Data Monitor Mode
EC-816
Page 1541 of 2898
Wiring Diagram=NJEC0767SEDAN MODELS AND HATCHBACK MODELS WITH ECM IN ENGINE COMPARTMENTNJEC0767S01
HEC831
EGR VOLUME CONTROL SYSTEMYD
Wiring Diagram
EC-817
Page 1542 of 2898
HATCHBACK MODELS WITH ECM IN CABINNJEC0767S02
HEC996
EGR VOLUME CONTROL SYSTEMYD
Wiring Diagram (Cont'd)
EC-818
Page 1543 of 2898
Diagnostic ProcedureNJEC0768
1 CHECK EGR VOLUME CONTROL SYSTEM OVERALL FUNCTION
1. Turn ignition switch ªOFFº.
2. Set the oscilloscope probe between ECM terminals 337, 338, 350, 351 and ground.
3. Start engine and let it idle.
4. Check the oscilloscope screen when revving engine up to 3,200 rpm and return to idle.
SEF247Z
OK or NG
OK©INSPECTION END
NG©GO TO 2.
2 CHECK EGR VOLUME CONTROL VALVE POWER SUPPLY CIRCUIT-I
1. Turn ignition switch ªOFFº.
2. Disconnect EGR volume control valve harness connector.
SEF388Y
3. Turn ignition switch ªONº.
4. Check voltage between EGR volume control valve terminals 2, 5 and ground with CONSULT-II or tester.
SEF412Y
OK or NG
OK©GO TO 7.
NG©GO TO 3.
EGR VOLUME CONTROL SYSTEMYD
Diagnostic Procedure
EC-819
Page 1544 of 2898

3 CHECK EGR VOLUME CONTROL VALVE POWER SUPPLY CIRCUIT-II
1. Turn ignition switch ªOFFº.
2. Disconnect ECM relay. (For ECM relay location, refer to ªEngine Control Component Parts Locationº.)
3. Check harness continuity between ECM relay terminal 5 and EGR volume control valve terminals 2 and 5. Refer to
Wiring Diagram.
Continuity should exist.
OK or NG
OK©GO TO 4.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
4 CHECK EGR VOLUME CONTROL VALVE POWER SUPPLY CIRCUIT-III
Check voltage between ECM relay terminal 3 and ground with CONSULT-II or tester.
SEF413Y
OK or NG
OK©GO TO 6.
NG©GO TO 5.
5 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E75, F36 (Sedan models and hatchback models with ECM in engine compartment)
+10A fuse
+Harness for open or short between ECM relay and battery
©Repair open circuit or short to ground or short to power in harness or connectors.
6 CHECK ECM RELAY
1. Apply 12V direct current between ECM relay terminals 1 and 2.
2. Check continuity between ECM relay terminals 3 and 5, 6 and 7.
SEF296X
OK or NG
OK©GO TO 7.
NG©Replace ECM relay.
EGR VOLUME CONTROL SYSTEMYD
Diagnostic Procedure (Cont'd)
EC-820