Diagnosis Procedure

CHECK FOR INTAKE AIR LEAK AND PCV HOSE
1. Start engine and run it at idle speed.
2. Listen for the sound of the intake air leak.
3. Check PCV hose connection.
  OK or NG
  
  OK: GO TO 2.
  
  NG: Repair or replace.
CHECK FOR EXHAUST SYSTEM CLOGGING
Stop engine and visually check exhaust tube, three way catalyst and muffler for dents.

OK or NG

OK: GO TO 3.

NG: Repair or replace.
PERFORM POWER BALANCE TEST
With CONSULT-III
1. Perform "POWER BALANCE" in "ACTIVE TEST" mode.
2. Is there any cylinder which does not produce a momentary engine speed drop?
Without CONSULT-III

When disconnecting each fuel injector harness connector (1) one at a time, is there any cylinder which does not produce a momentary engine speed drop?
- <= : Vehicle front
  Yes or No
  
  Yes: GO TO 4.
  
  No: GO TO 9.
  
  Fig 1: Identifying Fuel Injector Harness Connector
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK FUEL INJECTOR
Does each fuel injector make an operating sound at idle?

Yes or No

Yes: GO TO 5.

No: Check fuel injector(s) and circuit(s). Refer to FUEL INJECTOR .

Fig 2: Checking Fuel Injector
Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK FUNCTION OF IGNITION COIL-I
CAUTION: Perform the following procedure in a place with no combustible objects and good ventilation.
1. Turn ignition switch OFF.
2. Remove fuel pump fuse (1) in IPDM E/R (2) to release fuel pressure.
  NOTE: Do not use CONSULT-III to release fuel pressure, or fuel pressure applies again during the following procedure.
  - <= : Vehicle front
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel pressure.
5. Turn ignition switch OFF.
6. Remove all ignition coil harness connectors to avoid the electrical discharge from the ignition coils.
7. Remove ignition coil and spark plug of the cylinder to be checked.
  
  Fig 3: Identifying Fuel Pump Fuse And IPDM E/R
  Courtesy of NISSAN MOTOR CO., U.S.A.
8. Crank engine for 5 seconds or more to remove combustion gas in the cylinder.
9. Connect spark plug and harness connector to ignition coil.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm (0.52 - 0.66 in) between the edge of the spark plug and grounded metal portion as shown in the figure.
11. Crank engine for approximately 3 seconds, and check whether spark is generated between the spark plug and the grounded metal portion.
  Spark should be generated .
  
  Fig 4: Checking For Spark
  Courtesy of NISSAN MOTOR CO., U.S.A.
  CAUTION:
  - During the operation, always stay 0.5 m (19.7 in) or more away from the spark plug and the ignition coil. Be careful not to get an electrical shock while checking, because the electrical discharge voltage becomes 20 kV or more.
  - It might cause to damage the ignition coil if the gap of more than 17 mm (0.66 in) is made.
  NOTE: When the gap is less than 13 mm (0.52 in), a the spark might be generated even if the coil is malfunctioning.
  
  OK or NG
  
  OK: GO TO 9.
  
  NG: GO TO 6.
CHECK FUNCTION OF IGNITION COIL-II
1. Turn ignition switch OFF.
2. Disconnect spark plug and connect a non-malfunctioning spark plug.
3. Crank engine for approximately 3 seconds, and recheck whether spark is generated between the spark plug and the grounded metal portion.
  Spark should be generated .
  
  OK or NG
  
  OK: GO TO 7.
  
  NG: Check ignition coil, power transistor and their circuits. Refer to IGNITION SIGNAL .
CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.

OK or NG

OK: Replace spark plug(s) with standard type one(s). For spark plug type, refer to "SPARK PLUG : REMOVAL AND INSTALLATION ".

NG:
1. Repair or clean spark plug.
2. GO TO 8.
  
  Fig 5: Checking Spark Plug
  Courtesy of NISSAN MOTOR CO., U.S.A.
CHECK FUNCTION OF IGNITION COIL-III
1. Reconnect the initial spark plugs.
2. Crank engine for approximately 3 seconds, and recheck whether spark is generated between the spark plug and the grounded portion.
  Spark should be generated .
  
  OK or NG
  
  OK: INSPECTION END
  
  NG: Replace spark plug(s) with standard type one(s). For spark plug type, refer to "SPARK PLUG : REMOVAL AND INSTALLATION ".
CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to "ON-VEHICLE SERVICE ".

OK or NG

OK: GO TO 10.

NG: Check pistons, piston rings, valves, valve seats and cylinder head gaskets.
CHECK FUEL PRESSURE
1. Install all removed parts.
2. Release fuel pressure to zero. Refer to "FUEL PRESSURE CHECK ".
3. Install fuel pressure gauge and check fuel pressure. Refer to "FUEL PRESSURE CHECK ".
  At idling: Approximately 350 kPa (3.57 kg/cm ² , 51 psi)
  
  OK or NG
  
  OK: GO TO 12.
  
  NG: GO TO 11.
DETECT MALFUNCTIONING PART
Check the following.
- Fuel pump and circuit (Refer to FUEL PUMP .)
- Fuel pressure regulator (Refer to "FUEL PRESSURE CHECK ".)
- Fuel lines (Refer to FUEL INJECTOR AND FUEL TUBE .)
- Fuel filter for clogging
  Repair or replace.

CHECK IGNITION TIMING

Check the following items. Refer to "BASIC INSPECTION ".

SPECIFICATION CHART

Items	Specifications
Idle speed	CVT: 800 ± 50 RPM (in P or N position)
Idle speed	M/T: 650 ± 50 RPM (in Neutral position)
Ignition timing	CVT: 10 ± 5° BTDC (in Neutral position)
Ignition timing	M/T: 10 ± 5° BTDC (in Neutral position)

OK or NG

OK: GO TO 13.

NG: Follow the "BASIC INSPECTION ".

CHECK AIR FUEL RATIO (A/F) SENSOR 1 CIRCUIT FOR OPEN AND SHORT

Turn ignition switch OFF.
Disconnect air fuel ratio (A/F) sensor 1 harness connector.
- Air fuel ratio (A/F) sensor 1 (Bank 1) harness connector (1)
- Air fuel ratio (A/F) sensor 1 (Bank 1) (2)
- Air fuel ratio (A/F) sensor 1 (Bank 2) (3)
- Air fuel ratio (A/F) sensor 1 (Bank 2) harness connector (4)
Disconnect ECM harness connector.

Check harness continuity between the following terminals. Refer to WIRING DIAGRAM .

Fig 6: Identifying Fuel Ratio (A/F) Sensor 1 Harness Connectors

Courtesy of NISSAN MOTOR CO., U.S.A.

CONTINUITY REFERENCE CHART

Bank	A/F sensor 1 terminal	ECM terminal
1	1	45
1	2	49
2	1	53
2	2	57

Continuity should exist .

Check harness continuity between the following terminals and ground.

Refer to WIRING DIAGRAM .

CONTINUITY REFERENCE CHART

Bank 1		Bank 2
A/F sensor terminal	ECM terminal	A/F sensor terminal	ECM terminal
1	45	1	53
2	49	2	57

Continuity should not exist .

Also check harness for short to power.
OK or NG

OK: GO TO 14.

NG: Repair open circuit or short to ground or short to power in harness or connectors.

CHECK AIR FUEL RATIO (A/F) SENSOR 1 HEATER
Refer to "COMPONENT INSPECTION ".

OK or NG

OK: GO TO 16.

NG: GO TO 15.
REPLACE AIR FUEL RATIO (A/F) SENSOR 1
Replace malfunctioning air fuel ratio (A/F) sensor 1.
CAUTION:
- Discard any A/F sensor which has been dropped from a height of more than 0.5 m (19.7 in) onto a hard surface such as a concrete floor; use a new one.
- Before installing new A/F sensor, clean exhaust system threads using oxygen sensor thread cleaner [commercial service tool (J-43897-18 or J-43897-12)] and approved anti-seize lubricant (commercial service tool).
INSPECTION END
CHECK MASS AIR FLOW SENSOR
With CONSULT-III
1. Start engine and warm it up to normal operating temperature.
2. Check mass air flow sensor signal in "DATA MONITOR" mode with CONSULT-III.
  At idling : 1.0 - 4.0 g.m/sec
  
  At 2, 500 RPM : 4.0 - 10.0 g.m/sec
With GST
1. Start engine and warm it up to normal operating temperature.
2. Check mass air flow sensor signal in Service $01 with GST.
  At idling : 1.0 - 4.0 g.m/sec
  
  At 2, 500 RPM : 4.0 - 10.0 g.m/sec
  
  OK or NG
  
  OK: GO TO 17.
  
  NG: Check connectors for rusted terminals or loose connections in the mass air flow sensor circuit or ground. Refer to DTC P0101 MAF SENSOR .
CHECK SYMPTOM MATRIX CHART
Check items on the rough idle symptom in "SYMPTOM MATRIX CHART ".

OK or NG

OK: GO TO 18.

NG: Repair or replace.
ERASE THE 1ST TRIP DTC
Some tests may cause a 1st trip DTC to be set.

Erase the 1st trip DTC from the ECM memory after performing the tests. Refer to "EMISSION-RELATED DIAGNOSTIC INFORMATION ".

GO TO 19.
CHECK INTERMITTENT INCIDENT
Refer to TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT .

INSPECTION END