ignition INFINITI QX4 2001 Factory Service Manual

CONSULT-II Reference Value in Data Monitor
Mode
NBEC0388Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
START SIGNALIIgnition switch: ON,START,ON OFF,ON,OFF
ECM Terminals and Reference ValueNBEC0688Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
42 B/Y Start signal[Ignition switch ªONº]Approximately 0V
[Ignition switch ªSTARTº]9 - 12V
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START SIGNAL
CONSULT-II Reference Value in Data Monitor Mode
EC-621

Diagnostic ProcedureNBEC0391
1 INSPECTION START
Do you have CONSULT-II?
YesorNo
Ye s©GO TO 2.
No©GO TO 3.
2 CHECK OVERALL FUNCTION
With CONSULT-II
1. Turn ignition switch ªONº.
2. Check ªSTART SIGNALº in ªDATA MONITORº mode with CONSULT-II under the following conditions.
SEF072Y
OK or NG
OK©INSPECTION END
NG©GO TO 4.
3 CHECK OVERALL FUNCTION
Without CONSULT-II
Check voltage between ECM terminal 42 and ground under the following conditions.
SEF362X
OK or NG
OK©INSPECTION END
NG©GO TO 4.
4 CHECK STARTING SYSTEM
Turn ignition switch ªOFFº, then turn it to ªSTARTº.
Does starter motor operate?
YesorNo
Ye s©GO TO 5.
No©Refer to SC-10, ªSTARTING SYSTEMº.
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START SIGNAL
Diagnostic Procedure
EC-623

5 CHECK FUSE
1. Turn ignition switch ªOFFº.
2. Disconnect 7.5A fuse.
3. Check if 7.5A fuse is OK.
OK or NG
OK©GO TO 6.
NG©Replace 7.5A fuse.
6 CHECK START SIGNAL INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Disconnect ignition switch harness connector.
3. Check harness continuity between ECM terminal 42 and fuse block, ignition switch and fuse block. Refer to Wiring Dia-
gram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 8.
NG©GO TO 7.
7 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M32, F23
IFuse block (J/B) connectors M10, E3
IHarness for open or short between ignition switch and fuse
IHarness for open or short between ECM and fuse
©Repair open circuit or short to ground or short to power in harness or connectors.
8 CHECK INTERMITTENT INCIDENT
Refer to ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-140.
©INSPECTION END
START SIGNAL
Diagnostic Procedure (Cont'd)
EC-624

System DescriptionNBEC0392
Sensor Input Signal to ECMECM func-
tionActuator
Crankshaft position sensor (POS) Engine speed (POS signal)
Fuel pump
controlFuel pump relay Crankshaft position sensor (REF) Engine speed (REF signal)
Ignition switch Start signal
The ECM activates the fuel pump for several seconds after the ignition switch is turned on to improve engine
startability. If the ECM receives a 120É signal from the crankshaft position sensor (REF), it knows that the
engine is rotating, and causes the pump to operate. If the 120É signal is not received when the ignition switch
is on, the engine stalls. The ECM stops pump operation and prevents battery discharging, thereby improving
safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump relay, which in turn
controls the fuel pump.
Condition Fuel pump operation
Ignition switch is turned to ON. Operates for 1 second.
Engine running and cranking Operates.
When engine is stopped Stops in 1.5 seconds.
Except as shown aboveStops.
SEF018S
Component DescriptionNBEC0393The fuel pump with a fuel damper is an in-tank type (the pump and
damper are located in the fuel tank).
CONSULT-II Reference Value in Data Monitor
Mode
NBEC0394Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
FUEL PUMP RLYIIgnition switch is turned to ON. (Operates for 1 second.)
IEngine running and crankingON
Except as shown above OFF
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FUEL PUMP
System Description
EC-625

ECM Terminals and Reference Value=NBEC0686Specification data are reference values and are measured between each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECM's transistor. Use a ground other than ECM terminals, such as the ground.
TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
28 R/L Fuel pump relay[Ignition switch ªONº]
IFor 1 second after turning ignition switch ªONº
[Engine is running]0 - 1.5V
[Ignition switch ªONº]
I1 second passed after turning ignition switch
ªONº.BATTERY VOLTAGE
(11 - 14V)
FUEL PUMP
ECM Terminals and Reference Value
EC-626

Diagnostic ProcedureNBEC0397
1 CHECK OVERALL FUNCTION
1. Turn ignition switch ªONº.
2. Pinch fuel feed hose with two fingers.
SEF025Z
Fuel pressure pulsation should be felt on the fuel feed hose for 1 second after ignition switch is turned ªONº.
OK or NG
OK©INSPECTION END
NG©GO TO 2.
2 CHECK FUEL PUMP RELAY-1 and -2 POWER SUPPLY CIRCUIT-I
1. Turn ignition switch ªOFFº.
2. Disconnect fuel pump relay-1 and -2.
SEF346Z
3. Turn ignition switch ªONº.
4. Check voltage between terminals 2 and ground with CONSULT-II or tester.
SEF347Z
OK or NG
OK©GO TO 4.
NG©GO TO 3.
FUEL PUMP
Diagnostic Procedure
EC-628

6 CHECK FUEL PUMP RELAY POWER SUPPLY CIRCUIT-III
1. Turn ignition switch ªOFFº.
2. Disconnect fuel pump relay-2.
3. Turn ignition switch ªONº.
4. Check voltage between terminals 2, 3 and ground with CONSULT-II or tester.
SEF026Z
OK or NG
OK©GO TO 8.
NG©GO TO 7.
7 DETECT MALFUNCTIONING PART
Check the following.
I15A fuse in fusible link and relay box
IHarness for open or short between fuse and fuel pump relay-2
©Repair harness or connectors.
8 CHECK FUEL PUMP RELAY-2 GROUND CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between fuel pump relay-2 terminal 1 and ground.
Continuity should exist.
2. Also check harness for short to power.
OK or NG
©Repair open circuit or short to power in harness or connector.
FUEL PUMP
Diagnostic Procedure (Cont'd)
EC-630

9 CHECK FUEL PUMP POWER SUPPLY AND GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect fuel level sensor unit and fuel pump harness connector.
SEF021S
3. Check harness continuity between fuel pump terminal 2 and body ground, fuel pump terminal 1 and fuel pump relay-1
terminal 5. Refer to Wiring Diagram.
Continuity should exist.
4. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 11.
NG©GO TO 10.
10 DETECT MALFUNCTIONING PART
Check harness for open or short between fuel pump relay and fuel pump.
©Repair open circuit or short to ground or short to power in harness or connectors.
11 CHECK FUEL PUMP RELAY OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 28 and fuel pump relay-1 terminal 1. Refer to Wiring Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 13.
NG©GO TO 12.
12 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors E1, M1
IHarness connectors M32, F23
IHarness for open or short between ECM and fuel pump relay-1
©Repair open circuit or short to ground or short to power in harness or connectors.
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FUEL PUMP
Diagnostic Procedure (Cont'd)
EC-631

13 CHECK FUEL PUMP RELAY-1 AND -2
With CONSULT-II
1. Reconnect fuel pump relay-1 and -2, fuel level sensor unit and fuel pump harness connector and ECM harness con-
nector.
2. Turn ignition switch ªONº.
3. Turn fuel pump relay-1, -2 ªONº and ªOFFº in ªACTIVE TESTº mode with CONSULT-II and check operating sound.
SEF073Y
Without CONSULT-II
Check continuity between terminals 3 and 5 under the following conditions.
SEF608X
OK or NG
OK©GO TO 14.
NG©Replace fuel pump relay.
14 CHECK FUEL PUMP
1. Disconnect fuel level sensor unit and fuel pump harness connector.
2. Check resistance between fuel level sensor unit and fuel pump terminals 1 and 2.
SEF027Z
OK or NG
OK©GO TO 15.
NG©Replace fuel pump.
FUEL PUMP
Diagnostic Procedure (Cont'd)
EC-632

4 CHECK POWER STEERING OIL PRESSURE SWITCH GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch ªOFFº.
2. Disconnect power steering oil pressure switch harness connector.
SEF028Z
3. Check harness continuity between power steering oil pressure switch terminal 2 and engine ground. Refer to Wiring
Diagram.
Continuity should exist.
4. Also check harness for short to power.
OK or NG
OK©GO TO 5.
NG©Repair open circuit or short to power in harness or connectors.
5 CHECK POWER STEERING OIL PRESSURE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 47 and power steering oil pressure switch terminal 1. Refer to Wiring
Diagram.
Continuity should exist.
3. Also check harness for short to ground and short to power.
OK or NG
OK©GO TO 6.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
6 CHECK POWER STEERING OIL PRESSURE SWITCH
1. Disconnect power steering oil pressure switch harness connector then start engine.
2. Check continuity between power steering oil pressure switch terminals 1 and 2 under the following conditions.
SEF364X
OK or NG
OK©GO TO 7.
NG©Replace power steering oil pressure switch.
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POWER STEERING OIL PRESSURE SWITCH
Diagnostic Procedure (Cont'd)
EC-637