Page 798 of 2898

SEF543X
NATS (Nissan Anti-theft System)NJEC0591+If the security indicator lights up with the ignition switch
in the ªONº position or ªNATS MALFUNCTIONº is dis-
played on ªSELF-DIAG RESULTSº screen, perform self-
diagnostic results mode with CONSULT-II using NATS pro-
gram card. Refer to NATS (Nissan Anti-Theft System) in EL
section.
+Confirm no self-diagnostic results of NATS is displayed
before touching ªERASEº in ªSELF-DIAG RESULTSº
mode with CONSULT-II.
+When replacing ECM, initialization of NATS system and
registration of all NATS ignition key IDs must be carried
out with CONSULT-II using NATS program card.
Therefore, be sure to receive all keys from vehicle owner.
Regarding the procedure of NATS initialization and NATS
ignition key ID registration, refer to CONSULT-II operation
manual, NATS.
Malfunction Indicator (MI)
DESCRIPTIONNJEC0032
SAT652J
The MI is located on the instrument panel.
1. The MI will light up when the ignition switch is turned ON without the engine running. This is a bulb check.
+If the MI does not light up, refer to EL-184, ªWARNING LAMPSº or see EC-591.
2. When the engine is started, the MI should go off.
If the MI remains on, the on board diagnostic system has detected an engine system malfunction.
On Board Diagnostic System FunctionNJEC0032S01The on board diagnostic system has the following four functions.
Diagnostic Test Mode I
1. BULB CHECK:
This function checks the MI bulb for damage (blown, open circuit, etc.).
If the MI does not come on, check MI circuit and ECM test mode selector. (See the following page.)
2. MALFUNCTION WARNING:
MI Condition
ON When the malfunction is detected or the ECM's CPU is malfunctioning.
OFF No malfunction.
ON BOARD DIAGNOSTIC SYSTEM DESCRIPTIONQG
NATS (Nissan Anti-theft System)
EC-74
Page 837 of 2898

27 CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªENG SPEEDº in ªDATA MONITORº mode with CONSULT-II.
3. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 29.
NG©GO TO 28.
28 CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of a problem, but this is rarely
the case.)
2. Perform initialization of NATS system and registration of NATS ignition key IDs. Refer to ªNATS (Nissan Anti-Theft
System)º, EC-74.
©GO TO 22.
29 CHECK IGNITION TIMING
1. Start engine and warm it up to normal operating temperature.
2. Check ignition timing at idle using a timing light.
SEF984U
Ignition timing:
M/T 8ɱ5É BTDC
A/T 10ɱ5É BTDC (in ªPº or ªNº position)
OK or NG
OK©GO TO 37.
NG©GO TO 30.
30 CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-28, ªInstallationº.
OK or NG
OK©GO TO 28.
NG©1. Repair the timing chain installation.
2. GO TO 22.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG
Basic Inspection/Sedan (Cont'd)
EC-113
Page 838 of 2898

31 CHECK IGNITION TIMING
1. Start engine and let it idle.
2. Check ignition timing at idle using a timing light.
SEF984U
Ignition timing:
M/T 8ɱ5É BTDC
A/T 10ɱ5É BTDC (in ªPº or ªNº position)
OK or NG
OK©GO TO 37.
NG©GO TO 22.
32 PERFORM IDLE AIR VOLUME LEARNING
Refer to ªIdle Air Volume Learningº, EC-57.
Which is the result CMPLT or INCMP?
CMPLT or INCMP
CMPLT©GO TO 33.
INCMP©1. Follow the construction of ªIdle Air volume Learningº.
2. GO TO 32.
33 CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªENG SPEEDº in ªDATA MONITORº mode with CONSULT-II.
3. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 35.
NG©GO TO 34.
34 CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function.
(ECM may be the cause of a problem, but this is rarely the case.)
2. Perform initialization of NATS system and registration of NATS ignition key IDs. Refer to ªNATS (Nissan Anti-Theft
System)º, EC-74.
©GO TO 32.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG
Basic Inspection/Sedan (Cont'd)
EC-114
Page 849 of 2898

23 CHECK IACV-AAC VALVE CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Check IACV-AAC valve circuit for open and short. Refer to ªDiagnostic Procedureº, EC-380.
OK or NG
OK©GO TO 24.
NG©1. Repair or replace.
2. GO TO 25.
24 REPLACE IACV-AAC VALVE
Replace IACV-AAC valve.
©GO TO 25.
25 PERFORM IDLE AIR VOLUME LEARNING
Refer to ªIdle Air Volume Learningº, EC-57.
Which is the result CMPLT or INCMP?
CMPLT or INCMP
CMPLT©GO TO 26.
INCMP©1. Follow the construction of ªIdle Air Volume Learningº.
2. GO TO 21.
26 CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªENG SPEEDº in ªDATA MONITORº mode with CONSULT-II.
3. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 28.
NG©GO TO 27.
27 CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of a problem, but this is rarely
the case.)
2. Perform initialization of NATS system and registration of NATS ignition key IDs. Refer to ªNATS (Nissan Anti-Theft
System)º, EC-74.
©GO TO 21.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG
Basic Inspection/Sedan (Cont'd)
EC-125
Page 851 of 2898

31 PERFORM IDLE AIR VOLUME LEARNING
Refer to ªIdle Air Volume Learningº, EC-57.
Which is the result CMPLT or INCMP?
CMPLT or INCMP
CMPLT©GO TO 32.
INCMP©1. Follow the construction of ªIdle Air volume Learningº.
2. GO TO 31.
32 CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªENG SPEEDº in ªDATA MONITORº mode with CONSULT-II.
3. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 34.
NG©GO TO 33.
33 CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function.
(ECM may be the cause of a problem, but this is rarely the case.)
2. Perform initialization of NATS system and registration of NATS ignition key IDs. Refer to ªNATS (Nissan Anti-Theft
System)º, EC-74.
©GO TO 31.
34 CHECK IGNITION TIMING AGAIN
Check ignition timing again. Refer to Test No. 30.
OK or NG
OK©GO TO 36.
NG©GO TO 35.
35 CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-28, ªInstallationº.
OK or NG
OK©GO TO 33.
NG©1. Repair the timing chain installation.
2. GO TO 31.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG
Basic Inspection/Sedan (Cont'd)
EC-127
Page 866 of 2898

27 CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªENG SPEEDº in ªDATA MONITORº mode with CONSULT-II.
3. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 29.
NG©GO TO 28.
28 CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of a problem, but this is rarely
the case.)
2. Perform initialization of NATS system and registration of NATS ignition key IDs. Refer to ªNATS (Nissan Anti-Theft
System)º, EC-74.
©GO TO 22.
29 CHECK IGNITION TIMING
1. Start engine and warm it up to normal operating temperature.
2. Check ignition timing at idle using a timing light.
SEF984U
Ignition timing:
M/T 8ɱ5É BTDC
A/T 10ɱ5É BTDC (in ªPº or ªNº position)
OK or NG
OK©GO TO 37.
NG©GO TO 30.
30 CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-28, ªInstallationº.
OK or NG
OK©GO TO 28.
NG©1. Repair the timing chain installation.
2. GO TO 22.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG
Basic Inspection/Hatchback (Cont'd)
EC-142
Page 867 of 2898

31 CHECK IGNITION TIMING
1. Start engine and let it idle.
2. Check ignition timing at idle using a timing light.
SEF984U
Ignition timing:
M/T 8ɱ5É BTDC
A/T 10ɱ5É BTDC (in ªPº or ªNº position)
OK or NG
OK©GO TO 37.
NG©GO TO 22.
32 PERFORM IDLE AIR VOLUME LEARNING
Refer to ªIdle Air Volume Learningº, EC-57.
Which is the result CMPLT or INCMP?
CMPLT or INCMP
CMPLT©GO TO 33.
INCMP©1. Follow the construction of ªIdle Air Volume Learningº.
2. GO TO 32.
33 CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªENG SPEEDº in ªDATA MONITORº mode with CONSULT-II.
3. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 35.
NG©GO TO 34.
34 CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function.
(ECM may be the cause of a problem, but this is rarely the case.)
2. Perform initialization of NATS system and registration of NATS ignition key IDs. Refer to ªNATS (Nissan Anti-Theft
System)º, EC-74.
©GO TO 32.
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG
Basic Inspection/Hatchback (Cont'd)
EC-143
Page 874 of 2898

19 CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Select ªENG SPEEDº in ªDATA MONITORº mode with CONSULT-II.
3. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
M/T: 700±50 rpm
A/T: 800±50 rpm (in ªPº or ªNº position)
OK or NG
OK©GO TO 21.
NG©GO TO 20.
20 CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of a problem, but this is rarely
the case.)
2. Perform initialization of NATS system and registration of NATS ignition key IDs. Refer to ªNATS (Nissan Anti-Theft
system)º, EC-74.
©GO TO 14.
21 CHECK IGNITION TIMING
1. Start engine and warm it up to normal operating temperature.
2. Perform initialization of NATS system and registration of NATS ignition key IDs. Refer to ªNATS (Nissan Anti-Theft
System)º, EC-74.
SEM872F
Ignition timing:
M/T 8ɱ5É BTDC
A/T 10ɱ5É BTDC (in ªPº or ªNº position)
OK©GO TO 29.
NG©GO TO 22.
22 CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM section.
OK or NG
OK©GO TO 20.
NG©1. Repair the timing chain installation.
2. GO TO 14..
TROUBLE DIAGNOSIS Ð BASIC INSPECTIONQG
Basic Inspection/Hatchback (Cont'd)
EC-150