Page 777 of 2267
3 CHECK OVERALL FUNCTION
Without CONSULT-II
1. Turn ignition switch to ªSTARTº.
2. Check voltage between ECM terminal 41 and ground under the following conditions.
SEF142X
MTBL0143
OK or NG
OK©INSPECTION END
NG©GO TO 4.
4 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M50, F104
I10A fuse
IHarness for open or short between ECM and ignition switch
OK or NG
OK©GO TO 5.
NG©Repair open circuit or short to ground or short to power in harness or connectors.
5 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-QG-102.
©INSPECTION END
Condition Voltage
Ignition switch ªSTARTº Battery voltage
Except above Approximately 0V
START SIGNALQG16I18DE
Diagnostic Procedure (Cont'd)
EC-335
Page 778 of 2267

System DescriptionNCEC0444
Sensor Input Signal to ECMECM func-
tionActuator
Camshaft position sensor (PHASE) Engine speed
Fuel pump
controlFuel pump relay
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 180É signal from the camshaft position sensor, it knows that the engine is
rotating, and causes the pump to perform. If the 180É 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 (Signal is not sent from camshaft position sensor.) Stops in 1.5 seconds
Except as shown aboveStops
Component DescriptionNCEC0501A turbine type design fuel pump is used in the fuel tank.
CONSULT-II Reference Value in Data Monitor
Mode
NCEC0445
MONITOR ITEM CONDITION SPECIFICATION
FUEL PUMP RLYIIgnition switch is turned to ON (Operates for 1 second)
IEngine running and cranking
IWhen engine is stopped (stops in 1.5 seconds)ON
IExcept as shown above OFF
AEC801
FUEL PUMPQG16I18DE
System Description
EC-336
Page 779 of 2267
ECM Terminals and Reference ValueNCEC0446Specification 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)
21 B/P Fuel pump relay[Ignition switch ªONº]
IFor 1 second after turning ignition switch ªONº
[Engine is running]0-1V
[Ignition switch ªONº]
IMore than 1 second after turning ignition switch
ªONºBATTERY VOLTAGE
(11 - 14V)
FUEL PUMPQG16I18DE
ECM Terminals and Reference Value
EC-337
Page 780 of 2267
Wiring DiagramNCEC0447
YEC280
FUEL PUMPQG16I18DE
Wiring Diagram
EC-338
Page 781 of 2267
Diagnostic ProcedureNCEC0448
1 CHECK OVERALL FUNCTION
1. Turn ignition switch ªONº.
2. Pinch fuel feed hose with fingers.
SEF143XFuel 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 POWER SUPPLY
1. Turn ignition switch ªOFFº.
2. Disconnect fuel pump relay.
SEF071X3. Turn ignition switch ªONº.
4. Check voltage between terminals 1, 3 and ground with CONSULT-II or tester.
SEF144XVoltage: Battery voltage
OK or NG
OK©GO TO 4.
NG©GO TO 3.
FUEL PUMPQG16I18DE
Diagnostic Procedure
EC-339
Page 782 of 2267

3 DETECT MALFUNCTIONING PART
Check the following.
I15A fuse
IHarness for open or short between fuse and fuel pump relay
©Repair harness or connectors.
4 CHECK POWER GROUND CIRCUIT
1. Turn ignition switch ªOFFº.
2. Disconnect fuel pump harness connector.
SEF299W3. Check harness continuity between fuel pump harness connector terminal 2 and body ground, terminal 1 and fuel pump relay connector
terminal 9J.
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 6.
NG©GO TO 5.
5 DETECT MALFUNCTIONING PART
Check the following.
IHarness for open or short between fuel pump and body ground
IHarness for open or short between fuel pump and fuel pump relay
©Repair open circuit or short to ground or short to power in harness or connectors.
6 CHECK OUTPUT SIGNAL CIRCUIT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 21 and fuel pump relay connector terminal 19C.
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 8.
NG©GO TO 7.
7 DETECT MALFUNCTIONING PART
Check the following.
IHarness connectors M50, F104
IHarness for open or short between ECM and fuel pump relay
NG©Repair open circuit or short to ground or short to power in harness or connectors.
FUEL PUMPQG16I18DE
Diagnostic Procedure (Cont'd)
EC-340
Page 783 of 2267
8 CHECK FUEL PUMP RELAY
Refer to ªComponent Inspectionº, EC-QG-341.
OK or NG
OK©GO TO 9.
NG©Replace fuel pump relay.
9 CHECK FUEL PUMP
Refer to ªComponent Inspectionº, EC-QG-341.
OK or NG
OK©GO TO 10.
NG©Replace fuel pump.
10 CHECK INTERMITTENT INCIDENT
Perform ªTROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENTº, EC-QG-102.
©INSPECTION END
Component InspectionNCEC0449FUEL PUMP RELAYNCEC0449S01Check continuity between terminals 3 and 5.
Conditions Continuity
12V direct current supply between terminals 1 and 2 Yes
No current supply No
If NG, replace relay.
FUEL PUMPNCEC0449S021. Disconnect fuel pump harness connector.
2. Check resistance between terminals 1 and 2.
Resistance: 0.2 - 5.0W[at 25ÉC (77ÉF)]
If NG, replace fuel pump.
SEF145X
SEF326W
FUEL PUMPQG16I18DE
Diagnostic Procedure (Cont'd)
EC-341
Page 784 of 2267

Component DescriptionNCEC0451The power steering oil pressure switch is attached to the power
steering high-pressure tube and detects a power steering load.
When a power steering load is detected, it signals the ECM. The
ECM adjusts the IACV-AAC valve to increase the idle speed and
adjust for the increased load.
CONSULT-II Reference Value in Data Monitor
Mode
NCEC0452Specification data are reference values.
MONITOR ITEM CONDITION SPECIFICATION
PW/ST SIGNALIEngine: After warming up, idle
the engineSteering wheel in neutral position
(forward direction)OFF
The steering wheel is fully turned ON
ECM Terminals and Reference ValueNCEC0453Specification 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)
46 PU/WPower steering oil pressure
switch[Engine is running]
ISteering wheel is fully turnedApproximately 0V
[Engine is running]
ISteering wheel is not turnedApproximately 5V
NEF124A Power steering oil pressure switch
POWER STEERING OIL PRESSURE SWITCHQG16I18DE
Component Description
EC-342