NISSAN PICK-UP 2001 Repair Manual

Wiring DiagramNEEC0194
GEC296A
DTC P0172 FUEL INJECTION SYSTEM
FUNCTION
KA24DE (EURO OBD)
Wiring Diagram
EC-3246

Diagnostic ProcedureNEEC0195
1 CHECK FOR EXHAUST AIR LEAK
1. Start engine and run it at idle.
2. Listen for an exhaust air leak before three way catalyst.
SEF099P
OK or NG
OK©GO TO 2.
NG©Repair or replace.
2 CHECK HEATED OXYGEN SENSOR 1 CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect heated oxygen sensor 1 harness connector and ECM harness connector.
SEF331VC
3. Check harness continuity between ECM terminal 50 and terminal 2. Refer to wiring diagram.
Continuity should exist.
4. Check harness continuity between ECM terminal 50 (or terminal 2) and ground. Refer to wiring diagram.
Continuity should not exist.
5. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 3.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
DTC P0172 FUEL INJECTION SYSTEM
FUNCTION
KA24DE (EURO OBD)
Diagnostic Procedure
EC-3247

3 CHECK FUEL PRESSURE
1. Release fuel pressure to zero.
Refer to EC-3033.
2. Install fuel pressure gauge and check fuel pressure.
At idling:
When fuel pressure regulator valve vacuum hose is connected.
Approximately 235 kPa (2.35 bar, 2.4 kg/cm
2, 34 psi)
When fuel pressure regulator valve vacuum hose is disconnected.
Approximately 294 kPa (2.94 bar, 3.0 kg/cm
2, 43 psi)
OK or NG
OK©GO TO 5.
NG©GO TO 4.
4 DETECT MALFUNCTIONING PART
Check the following.
+Fuel pump and circuit (Refer to EC-3378.)
+Fuel pressure regulator (Refer to EC-3034.)
©Repair or replace.
5 CHECK MASS AIR FLOW SENSOR
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check ªMASS AIR FLOWº in ªDATA MONITORº mode with CONSULT-II.
at idling: 0.9 - 5.8 g´m/sec
at 2,500 rpm: 7.5 - 13.2 g´m/sec
With GST
1. Start engine and warm it up to normal operating temperature.
2. Check mass air flow sensor signal in MODE 1 with GST.
at idling: 0.9 - 5.8 g´m/sec
at 2,500 rpm: 7.5 - 13.2 g´m/sec
OK or NG
OK©GO TO 6.
NG©Check connectors for rusted terminals or loose connections in the mass air flow sensor
circuit or engine grounds. Refer to EC-3143, EC-3151.
DTC P0172 FUEL INJECTION SYSTEM
FUNCTION
KA24DE (EURO OBD)
Diagnostic Procedure
EC-3248

6 CHECK FUNCTION OF INJECTORS
With CONSULT-II
1. Install all parts removed.
2. Start engine.
3. Perform ªPOWER BALANCEº in ªACTIVE TESTº mode with CONSULT-II.
SEF981Z
4. Make sure that each circuit produces a momentary engine speed drop.
Without CONSULT-II
1. Install all parts removed.
2. Start engine.
3. Listen to each injector operating sound.
MEC703B
Clicking noise should be heard.
OK or NG
OK©GO TO 7.
NG©Perform trouble diagnosis for ªINJECTORSº, EC-3370.
7 REMOVE 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 assembly. Refer to EC-3034.
Keep fuel hose and all injectors connected to injector gallery.
©GO TO 8.
8 CHECK INJECTOR
1. Disconnect all injector harness connectors.
2. Disconnect all ignition coil harness connectors.
3. Prepare pans or saucers under each injectors.
4. Crank engine for about 3 seconds.
Make sure fuel does not drip from injector.
OK or NG
OK (Does not drip)©GO TO 9.
NG (Drips)©Replace the injectors from which fuel is dripping. Always replace O-ring with new one.
DTC P0172 FUEL INJECTION SYSTEM
FUNCTION
KA24DE (EURO OBD)
Diagnostic Procedure
EC-3249

9 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-3123.
©INSPECTION END
DTC P0172 FUEL INJECTION SYSTEM
FUNCTION
KA24DE (EURO OBD)
Diagnostic Procedure
EC-3250

On Board Diagnosis LogicNEEC0202When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the CKP
sensor signal to vary, the ECM can determine that a misfire is occurring.
Sensor Input Signal to ECM ECM function
Crankshaft position sensor (OBD) Engine speed On board diagnosis of misfire
The misfire detection logic consists of the following two conditions.
1. One Trip Detection Logic (Three Way Catalyst Damage)
On the first trip that a misfire condition occurs that can damage the three way catalyst (TWC) due to
overheating, the MI will blink.
When a misfire condition occurs, the ECM monitors the CKP sensor signal every 200 engine revolutions
for a change.
When the misfire condition decreases to a level that will not damage the TWC, the MI will turn off.
If another misfire condition occurs that can damage the TWC on a second trip, the MI will blink.
When the misfire condition decreases to a level that will not damage the TWC, the MI will remain on.
If another misfire condition occurs that can damage the TWC, the MI will begin to blink again.
2. Two Trip Detection Logic (Exhaust quality deterioration)
For misfire conditions that will not damage the TWC (but will affect vehicle emissions), the MI will only light
when the misfire is detected on a second trip. During this condition, the ECM monitors the CKP sensor
signal every 1,000 engine revolutions.
A misfire malfunction can be detected on any one cylinder or on multiple cylinders.
DTC No. Malfunction is detected when ... Check Items (Possible Cause)
P0300
0300+Multiple cylinders misfire.+Improper spark plug
+Insufficient compression
+Incorrect fuel pressure
+The injector circuit is open or shorted
+Injectors
+Intake air leak
+The ignition secondary circuit is open or shorted
+Lack of fuel
+Drive plate/Flywheel
+Heated oxygen sensor 1
+Incorrect distributor rotor P0301
0301+No. 1 cylinder misfires.
P0302
0302+No. 2 cylinder misfires.
P0303
0303+No. 3 cylinder misfires.
P0304
0304+No. 4 cylinder misfires.
SEF174Y
DTC Confirmation ProcedureNEEC0203CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDTC Confirmation Procedureº has been previously conducted,
always turn ignition switch OFF and wait at least 5 seconds before
conducting the next test.
With CONSULT-II
1) Turn ignition switch ON, and select ªDATA MONITORº mode
with CONSULT-II.
2) Start engine and warm it up to normal operating temperature.
DTC P0300 - P0304 NO.4-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
KA24DE (EURO OBD)
On Board Diagnosis Logic
EC-3251

3) Turn ignition switch OFF and wait at least 5 seconds.
4) Start engine again and drive at 1,500 to 3,000 rpm for at least
3 minutes.
Hold the accelerator pedal as steady as possible.
NOTE:
Refer to the freeze frame data for the test driving conditions.
5) If 1st trip DTC is detected, go to ªDiagnostic Procedureº,
EC-3252.
With GST
Follow the procedure ªWith CONSULT-IIº.
Diagnostic ProcedureNEEC0204
1 CHECK FOR INTAKE AIR LEAK
1. Start engine and run it at idle speed.
2. Listen for the sound of the intake air leak.
OK or NG
OK©GO TO 2.
NG©Discover air leak location and repair.
2 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 it.
DTC P0300 - P0304 NO.4-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
KA24DE (EURO OBD)
DTC Confirmation Procedure
EC-3252

3 PERFORM POWER BALANCE TEST
With CONSULT-II
1. Perform ªPOWER BALANCEº in ªACTIVE TESTº mode.
SEF981Z
2. Is there any cylinder which does not produce a momentary engine speed drop?
Without CONSULT-II
When disconnecting each injector harness connector one at a time, is there any cylinder which does not produce a
momentary engine speed drop?
SEF319V
YesorNo
Ye s©GO TO 4.
No©GO TO 7.
4 CHECK INJECTOR
Does each injector make an operating sound at idle?
MEC703B
YesorNo
Ye s©GO TO 5.
No©Check injector(s) and circuit(s). Refer to EC-3370.
DTC P0300 - P0304 NO.4-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
KA24DE (EURO OBD)
Diagnostic Procedure
EC-3253

5 CHECK IGNITION SPARK
1. Turn ignition switch OFF.
2. Disconnect ignition wire from spark plug.
3. Connect a known good spark plug to the ignition wire.
4. Place end of spark plug against a suitable ground and crank engine.
5. Check for spark.
SEF282G
OK or NG
OK©GO TO 7.
NG©GO TO 6.
6 CHECK IGNITION WIRES
1. Inspect wires for cracks, damage, burned terminals and for improper fit.
2. Measure the resistance of wires to their distributor cap terminal. Move each wire while testing to check for intermittent
breaks.
SEF174P
Resistance:
13.6 - 18.4 kW/m (4.15 - 5.61 kW/ft) at 25ÉC (77ÉF)
If the resistance exceeds the above specification, inspect ignition wire to distributor cap connection. Clean connection
or replace the ignition wire with a new one.
OK or NG
OK©Check distributor rotor head for incorrect parts. Check ignition coil, power transistor and
their circuits. Refer to EC-3361.
NG©Replace.
DTC P0300 - P0304 NO.4-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
KA24DE (EURO OBD)
Diagnostic Procedure
EC-3254

7 CHECK SPARK PLUGS
Remove the spark plugs and check for fouling, etc.
SEF156I
OK or NG
OK©GO TO 8.
NG©Repair or replace spark plug(s) with standard type one(s). For spark plug type, refer to
ªENGINE MAINTENANCEº, MA section.
8 CHECK COMPRESSION PRESSURE
Refer to EM section.
+Check compression pressure.
Standard:
1,226 kPa (12.3 bar, 12.5 kg/cm
2, 178 psi)/300 rpm
Minimum:
1,030 kPa (10.3 bar, 10.5 kg/cm
2, 149 psi)/300 rpm
Difference between each cylinder:
98 kPa (0.98 bar, 1.0 kg/cm
2, 14 psi)/300 rpm
OK or NG
OK©GO TO 9.
NG©Check pistons, piston rings, valves, valve seats and cylinder head gaskets.
9 CHECK FUEL PRESSURE
1. Install any parts removed.
2. Release fuel pressure to zero. Refer to EC-3033.
3. Install fuel pressure gauge and check fuel pressure.
AEC064B
At idle: Approx. 235 kPa (2.35 bar, 2.4 kg/cm2, 34 psi)
OK or NG
OK©GO TO 11.
NG©GO TO 10.
DTC P0300 - P0304 NO.4-1CYLINDER MISFIRE, MULTIPLE CYLINDER
MISFIRE
KA24DE (EURO OBD)
Diagnostic Procedure
EC-3255