Diagnosis Procedure

WARNING: This page is about a different car, the 2012 Nissan Pathfinder. However, it is still accessible from the selected car via links, so may be relevant.

CHECK FOR INTAKE AIR LEAKAGE AND PCV HOSE
1. Start engine and run it at idle speed.
2. Listen for the sound of the intake air leakage.
3. Check PCV hose connection.
OK or NG

OK: GO TO 2.

NG: Discover air leakage location and repair.
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 malfunctioning part.
PERFORM POWER BALANCE TEST
With CONSULT
1. Perform "POWER BALANCE" in "ACTIVE TEST" mode.
2. Is there any cylinder which does not produce a momentary engine speed drop?
Without CONSULT

When disconnecting each fuel injector harness connector one at a time, is there any cylinder which does not produce a momentary engine speed drop?

Fig 1: Identifying Injector Harness Connectors (Bank 1 And 2)
Courtesy of NISSAN NORTH AMERICA, INC.

Yes or No

Yes: GO TO 4.

No: GO TO 7.
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 "DIAGNOSIS PROCEDURE ".

Fig 2: Checking Fuel Injector Operating Sound
Courtesy of NISSAN NORTH AMERICA, INC.
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 to release fuel pressure, or fuel pressure applies again during the following procedure.
3. Start engine.
4. After engine stalls, crank it 2 or 3 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.
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.
  
  Fig 3: Identifying Fuel Pump Fuse And IPDM E/R
  Courtesy of NISSAN NORTH AMERICA, INC.
10. Fix ignition coil using a rope etc. with gap of 13 - 17 mm 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: Identifying Spark Length Between Edge Of Spark Plug And Grounded Metal Portion
Courtesy of NISSAN NORTH AMERICA, INC.
CAUTION:
- Never place the spark plug and the ignition coil within 50 cm each other. Be careful not to get an electrical shock while checking, because the electrical discharge voltage becomes 20 kV or more.
- It might damage the ignition coil if the gap of more than 17 mm is made.
NOTE: When the gap is less than 13 mm, 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 "DIAGNOSIS PROCEDURE ".
CHECK SPARK PLUG
Check the initial spark plug for fouling, etc.

OK or NG

OK: Replace malfunctioning spark plug(s) with standard type one(s). For spark plug type, refer to "STANDARD AND LIMIT ".

NG >>
1. Repair or clean spark plug Refer to IGNITION COIL ..
2. GO TO 8.
Fig 5: Identifying Initial Spark Plug
Courtesy of NISSAN NORTH AMERICA, INC.
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 malfunctioning spark plug(s) with standard type one(s). For spark plug type, refer to "STANDARD AND LIMIT ".
CHECK COMPRESSION PRESSURE
Check compression pressure. Refer to "COMPRESSION PRESSURE ".

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 "DIAGNOSIS PROCEDURE ".)
- Fuel pressure regulator (Refer to "FUEL PRESSURE CHECK ".)
- Fuel lines
- Fuel filter for clogging
Repair or replace malfunctioning part.

CHECK IGNITION TIMING

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

Items	Specifications
Target idle speed	650 ± 50 RPM (in P or N position)
Ignition timing	15 ± 5°BTDC (in P or N position)

OK or NG

OK: GO TO 13.

NG: Follow the "BASIC INSPECTION ".

CHECK AIR FUEL RATIO SENSOR 1 INPUT SIGNAL FOR OPEN AND SHORT

Turn ignition switch OFF.
Disconnect air fuel ratio (A/F) sensor 1 harness connector.

Fig 6: Identifying Air Fuel Ratio (A/F) Sensor 1 Harness Connector
Courtesy of NISSAN NORTH AMERICA, INC.
Disconnect ECM harness connector.

Check harness continuity between A/F sensor 1 terminals and ECM terminals as per the following. Refer to WIRING DIAGRAM .

	A/F sensor 1 terminal	ECM terminal
Bank 1	1	35
Bank 1	2	56
Bank 2	1	16
Bank 2	2	75

Check harness continuity between the following terminals and ground.

Refer to WIRING DIAGRAM .

Continuity should exist .

Bank 1		Bank 2
A/F sensor 1 terminal	ECM terminal	A/F sensor 1 terminal	ECM terminal
1	35	1	16
2	56	2	75

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 A/F SENSOR 1 HEATER
Refer to "COMPONENT INSPECTION ".

OK or NG

OK: GO TO 16.

NG: GO TO 15.
REPLACE A/F SENSOR 1
Replace malfunctioning A/F sensor 1. Refer to EXHAUST MANIFOLD AND THREE WAY CATALYST .
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

Check mass air flow sensor signal in "DATA MONITOR" mode with CONSULT.

3.0 - 9.0 g.m/sec: At idling

9.0 - 28.0 g.m/sec: At 2, 500 RPM

With GST

Check mass air flow sensor signal in Service $01 with GST.

3.0 - 9.0 g.m/sec: At idling

9.0 - 28.0 g.m/sec: At 2, 500 RPM

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 "DIAGNOSIS PROCEDURE ".
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 malfunctioning part.
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 "DTC INDEX ".

GO TO 19.
CHECK INTERMITTENT INCIDENT
Refer to "INTERMITTENT INCIDENT ".

>> INSPECTION END