Diagnostic Procedure

CHECK EXHAUST GAS LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust gas leak before three way catalyst (manifold).
Fig 1: Checking Exhaust Gas Leakage
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 2.

NG: Repair or replace.
CHECK FOR INTAKE AIR LEAK AND PCV HOSE
1. Listen for an intake air leak after the mass air flow sensor.
2. Check PCV hose connection.
OK or NG

OK: GO TO 3.

NG: Repair or replace.
CHECK HEATED OXYGEN SENSOR 1 CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 1 (HO2S1) harness connector.
3. Disconnect ECM harness connector.
4. Check harness continuity between HO2S1 terminal 2 and ECM terminal 35.
  Refer to WIRING DIAGRAM .
  
  Continuity should exist.
5. Check harness continuity between ECM terminal 35 or HO2S1 terminal 2 and ground.
  Refer to WIRING DIAGRAM .
  
  Fig 2: Identifying Heated Oxygen Sensor 1 Harness Connector
  Courtesy of NISSAN MOTOR CO., U.S.A.
  
  Continuity should not exist.
6. Also check harness for short to power and short ground.
OK or NG

OK: GO TO 4.

NG: Repair open circuit or short to ground or short to power in harness or connectors.
CHECK FUEL PRESSURE
1. Release fuel pressure to zero. Refer to "FUEL PRESSURE RELEASE ".
2. Install fuel pressure gauge and check fuel pressure. Refer to "FUEL PRESSURE CHECK ".
  At idling: Approximately 350 kPa (3.5 bar, 3.57 kg/cm ² , 51 psi)
OK or NG

OK: GO TO 6.

NG: GO TO 5.
DETECT MALFUNCTIONING PART
Check the following.
- Fuel pump and circuit (Refer to FUEL PUMP CIRCUIT .)
- Fuel pressure regulator (Refer to DIAGNOSTIC PROCEDURE .)
- Fuel lines (Refer to "FUEL INJECTOR AND FUEL TUBE ".)
- Fuel filter for clogging
  Repair or replace.
CHECK MASS AIR FLOW SENSOR
With CONSULT-II
1. Install all removed parts.
2. Check "MASS AIR FLOW" in "DATA MONITOR" mode with CONSULT-II.
  1.0 - 4.0 g.m/sec: at idling
  
  4.0 - 10 g.m/sec: at 2, 500 rpm
With GST
1. Install all removed parts.
2. Check mass air flow sensor signal in Service $01 with GST.
  1.0 - 4.0 g.m/sec: at idling
  
  4.0 - 10 g.m/sec: at 2, 500 rpm
OK or NG

OK: GO TO 7.

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 FUNCTION OF INJECTORS
With CONSULT-II
1. Start engine.
2. Perform "POWER BALANCE" in "ACTIVE TEST" mode with CONSULT-II.
3. Make sure that each circuit produces a momentary engine speed drop.
Fig 3: Generic Scan Tool - Power Balance
Courtesy of NISSAN MOTOR CO., U.S.A.

Without CONSULT-II
1. Start engine.
2. Listen to each injector operating sound.
  Clicking noise should be heard.
Fig 4: Checking Fuel Injector
Courtesy of NISSAN MOTOR CO., U.S.A.

OK or NG

OK: GO TO 8.

NG: Perform trouble diagnosis for INJECTOR CIRCUIT, refer to "INJECTOR CIRCUIT ".
CHECK INJECTOR
1. Confirm that the engine is cooled down and there are no fire hazards near the vehicle.
2. Turn ignition switch OFF.
3. Remove injector gallery assembly. Refer to "FUEL INJECTOR AND FUEL TUBE ".
  Keep fuel hose and all injectors connected to injector gallery.
  
  The injector harness connectors should remain connected.
4. Disconnect all ignition coil harness connectors.
5. Prepare pans or saucers under each injector.
6. Crank engine for about 3 seconds. Make sure that fuel sprays out from injectors.
  Fuel should be sprayed evenly for each injector.
  
  Fig 5: Checking Injector From Fuel Spray
  Courtesy of NISSAN MOTOR CO., U.S.A.
OK or NG

OK: GO TO 9.

NG: Replace injectors from which fuel does not spray out. Always replace O-ring with new ones.
CHECK INTERMITTENT INCIDENT
Refer to "TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT ".

INSPECTION END