Page 750 of 2898
Type-2NJEC0010S0102
HEC934
ENGINE AND EMISSION CONTROL OVERALL SYSTEMQG
Circuit Diagram (Cont'd)
EC-26
Page 751 of 2898
HATCHBACKNJEC0010S02Models with Swirl Control SystemNJEC0010S0201
HEC896
ENGINE AND EMISSION CONTROL OVERALL SYSTEMQG
Circuit Diagram (Cont'd)
EC-27
Page 752 of 2898
Models without Swirl Control SystemNJEC0010S0202
NEF327A
ENGINE AND EMISSION CONTROL OVERALL SYSTEMQG
Circuit Diagram (Cont'd)
EC-28
Page 753 of 2898
System DiagramNJEC0011
NEF328A
ENGINE AND EMISSION CONTROL OVERALL SYSTEMQG
System Diagram
EC-29
Page 754 of 2898
Vacuum Hose DrawingNJEC0012Refer to ªSystem Diagramº on EC-29 for vacuum control system.
NEF329A
ENGINE AND EMISSION CONTROL OVERALL SYSTEMQG
Vacuum Hose Drawing
EC-30
Page 777 of 2898

21 CHECK HEATED OXYGEN SENSOR 1 (FRONT) SIGNAL
With CONSULT-II
1. Stop engine.
2. Replace heated oxygen sensor 1 (front).
3. Start engine and warm it up to normal operating temperature.
4. Run engine at approx. 2,000 rpm for approx. 2 minutes under no-load.
5. See ªHO2S1 MNTR (B1)º in ªDATA MONITORº mode.
6. Running engine at 2,000 rpm under no-load (engine is warmed up to normal operating temperature.), check that the
monitor fluctuates between ªLEANº and ªRICHº more than 5 times during 10 seconds.
1 time: RICH®LEAN®RICH
2 times: RICH®LEAN®RICH®LEAN®RICH
Without CONSULT-II
1. Stop engine.
2. Replace heated oxygen sensor 1 (front).
3. Start engine and warm it up to normal operating temperature.
4. Run engine at approx. 2,000 rpm for approx. 2 minutes under no-load.
5. Set voltmeter probe between ECM terminal 62 and ground.
6. Make sure that the voltage fluctuates between 0 to 0.3V and 0.6 to 1.0V more than 5 times during 10 seconds at 2,000
rpm.
1 time: 0 - 0.3V®0.6 - 1.0V®0 - 0.3V
2 times: 0 - 0.3V®0.6 - 1.0V®0 - 0.3V®0.6 - 1.0V®0 - 0.3V
OK or NG
OK©INSPECTION END
NG©GO TO 22.
22 DETECT MALFUNCTIONING PART
Check the following.
1. Check fuel pressure regulator. Refer to EC-41.
2. Check mass air flow sensor and its circuit. Refer to EC-187.
3. Check injector and its circuit. Refer to EC-541.
Clean or replace if necessary.
4. Check engine coolant temperature sensor and its circuit. Refer to EC-201.
5. Check ECM function by substituting another known-good ECM.
(ECM may be the cause of a problem, but this is rarely the case.)
©GO TO 3.
23 CHECK HEATED OXYGEN SENSOR 1 (FRONT) HARNESS
1. Turn off engine and disconnect battery ground cable.
2. Disconnect ECM harness connector.
3. Disconnect heated oxygen sensor 1 (front) harness connector.
4. Check harness continuity between ECM terminal 62 and heated oxygen sensor 1 (front) harness connector terminal 1.
Refer to Wiring Diagram, EC-216.
Continuity should exist.
OK or NG
OK©GO TO 25.
NG©GO TO 24.
24 REPAIR OR REPLACE
Repair or replace harness between ECM and heated oxygen sensor 1 (front).
©GO TO 3.
BASIC SERVICE PROCEDUREQG
Inspection Procedure (Cont'd)
EC-53
Page 902 of 2898
Main Power Supply and Ground Circuit
WIRING DIAGRAMNJEC0047Sedan models and Hatchback Models with ECM in Engine CompartmentNJEC0047S01
HEC779
TROUBLE DIAGNOSIS FOR POWER SUPPLYQG
Main Power Supply and Ground Circuit
EC-178
Page 906 of 2898

2 CHECK ECM POWER SUPPLY CIRCUIT-I
1. Turn ignition switch ªOFFº and then ªONº.
2. Check voltage between ECM terminal 43 and ground with CONSULT-II or tester.
SEF291X
OK or NG
OK©GO TO 4.
NG©GO TO 3.
3 DETECT MALFUNCTIONING PART
Check the following.
+Harness connectors E74, F35 (If so equipped)
+Harness connectors M21, E106 (Sedan), M160, E175 or M169, F113 (Hatchback)
+Fuse block (J/B) connector M1, E103
+10A fuse
+Harness for open or short between ECM and ignition switch
©Repair harness or connectors.
4 CHECK ECM GROUND CIRCUIT FOR OPEN AND SHORT-I
1. Turn ignition switch ªOFFº.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminals 48, 57, 106, 108 and engine ground.
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 5.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
TROUBLE DIAGNOSIS FOR POWER SUPPLYQG
Main Power Supply and Ground Circuit (Cont'd)
EC-182