2001 INFINITI QX4 IDX

SEF955Y
ECM Terminals and Reference ValueNBEC0044PREPARATIONNBEC0044S011. ECM is located behind the instrument lower cover. For this
inspection, remove instrument lower cover.
2. Remove ECM harness protector.
MEC486B
3. Perform all voltage measurements with the connector con-
nected. Extend tester probe as shown to perform tests easily.
IOpen harness securing clip to make testing easier.
IUse extreme care not to touch 2 pins at one time.
IData is for comparison and may not be exact.
ECM HARNESS CONNECTOR TERMINAL LAYOUTNBEC0044S02
SEF970W
ECM INSPECTION TABLENBEC0044S03Specification data are reference values and are measured between
each terminal and ground.
CAUTION:
Do not use ECM ground terminals when measuring the input/
output voltage. Doing so may result in damage to the ECM's
transistor. Use ground other than the ECM terminals, such as
the ground.
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
ECM Terminals and Reference Value
EC-127

TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
13 OR/BIntake valve timing
control solenoid valves
(RH)[Engine is running]
IWarm-up condition
IIdle speedBattery voltage
[Engine is running]
IWarm-up condition
IEngine speed is 2,000 rpm.7-8V
SEF350Z
15 P/LIntake valve timing
control solenoid valves
(LH)[Engine is running]
IWarm-up condition
IIdle speedBattery voltage
[Engine is running]
IWarm-up condition
IEngine speed is 2,000 rpm.7-8V
SEF350Z
16 Y/GVIAS control solenoid
valve[Engine is running]
IIdle speedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
IEngine speed is above 5,000 rpm.0 - 1.0V
21
22
23
30
31
32Y/R
G/R
L/R
GY
PU/W
GY/RIgnition signal No. 1
Ignition signal No. 2
Ignition signal No. 3
Ignition signal No. 4
Ignition signal No. 5
Ignition signal No. 6[Engine is running]
IWarm-up condition
IIdle speed0 - 0.2VH
SEF399T
[Engine is running]
IWarm-up condition
IEngine speed is 2,500 rpm.0.1 - 0.3VH
SEF645T
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
ECM Terminals and Reference Value (Cont'd)
EC-129

TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
42 B/Y Start signal[Ignition switch ªONº]Approximately 0V
[Ignition switch ªSTARTº]9 - 12V
43 R Ignition switch[Ignition switch ªOFFº]0V
[Ignition switch ªONº]BATTERY VOLTAGE
(11 - 14V)
44 L PNP switch[Ignition switch ªONº]
IGear position is ªPº or ªNº.Approximately 0V
[Ignition switch ªONº]
IExcept the above gear positionBATTERY VOLTAGE
(11 - 14V)
45 B/RAir conditioner switch
signal[Engine is running]
IBoth A/C switch and blower switch are ªONº.Approximately 0V
[Engine is running]
IA/C switch is ªOFFº.Approximately 5V
47 R/BPower steering oil
pressure switch[Engine is running]
ISteering wheel is being turned.0 - 1.0V
[Engine is running]
ISteering wheel is not being turned.Approximately 5V
48 B ECM ground[Engine is running]
IIdle speedEngine ground
51 BR A/C cut signal[Engine is running]
IAir conditioner is operating.0 - 0.5V
52 PU Electrical load signal[Engine is running]
IRear window defogger: ON
IHi-beam headlamp: ONBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
IElectrical load: OFF0V
55 W/BSwirl control valve con-
trol vacuum check
switch[Engine is running]
IIdle speed
IEngine coolant temperature is between 15 to
50ÉC (59 to 122ÉF).Approximately 5V
[Engine is running]
IIdle speed
IEngine coolant temperature is above 55ÉC
(131ÉF).0 - 1.0V
56 OR/LThrottle position switch
(Closed position)[Engine is running]
IAccelerator pedal fully releasedBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
IAccelerator pedal depressedApproximately 0V
57 B ECM ground[Engine is running]
IIdle speedEngine ground
58 B/P Sensors' ground[Engine is running]
IWarm-up condition
IIdle speedApproximately 0V
59 BFuel level sensor
ground[Engine is running]
IIdle speedApproximately 0V
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
ECM Terminals and Reference Value (Cont'd)
EC-131

TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
71 OR/LHeated oxygen sensor
2 (rear) (bank 2)[Engine is running]
IWarm-up condition
IEngine speed is 2,000 rpm.0 - Approximately 1.0V
72 ORHeated oxygen sensor
2 (rear) (bank 1)[Engine is running]
IWarm-up condition
IEngine speed is 2,000 rpm.0 - Approximately 1.0V
73 B/PMass air flow sensor
ground[Engine is running]
IWarm-up condition
IIdle speedApproximately 0V
79 Y/GIntake valve timing
control position sen-
sors (RH)[Engine is running]
IWarm-up condition
IIdle speedApproximately 0.5V
SEF351Z
[Engine is running]
IWarm-up condition
IEngine speed is 2,000 rpm.Approximatley 0.5V
SEF352Z
80 L/RAbsolute pressure sen-
sor[Ignition switch ªONº]Approximately 4.4V
81 W/PURefrigerant pressure
sensor[Engine is running]
IWarm-up condition
IBoth A/C switch and blower switch are ªONº.
(Compressor operates.)0.36 - 3.88V
82 WThrottle position sensor
signal output[Engine is running]
IWarm-up condition
IAccelerator pedal fully releasedApproximately 0.4V
[Ignition switch ªONº]
IAccelerator pedal fully depressedApproximately 4V
83 Y/PU Fuel level sensor[Ignition switch ªONº]Approximately 0 - 4.8V
Output voltage varies with
fuel level.
84 L/GEVAP control system
pressure sensor[Ignition switch ªONº]Approximately 3.4V
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
ECM Terminals and Reference Value (Cont'd)
EC-133

TERMI-
NAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
91 R Throttle position sensor[Engine is running]
IWarm-up condition
IAccelerator pedal fully released0.15 - 0.85V
[Ignition switch ªONº]
IAccelerator pedal fully depressed3.5 - 4.7V
92 G/BFuel tank temperature
sensor[Engine is running]Approximately 0 - 4.8V
Output voltage varies with
fuel tank temperature.
93 W Knock sensor[Engine is running]
IIdle speedApproximately 2.5V
101
102
103
104
105
107R/B
L/W
R/W
PU/R
R/Y
R/LInjector No. 1
Injector No. 5
Injector No. 2
Injector No. 6
Injector No. 3
Injector No. 4[Engine is running]
IIdle speedBATTERY VOLTAGE
(11 - 14V)
106
108B
BECM ground[Engine is running]
IIdle speedEngine ground
11 0
11 2B/W
B/WPower supply for ECM[Ignition switch ªONº]BATTERY VOLTAGE
(11 - 14V)
111 P/B Sensors' power supply[Ignition switch ªONº]Approximately 5V
114 G/RCommunication line
(LAN)[Engine is running]
IIdle speedApproximately 2V
115 LG/R Data link connector[Ignition switch ªONº]
ICONSULT-II or GST is disconnected.Approximately 2V
H: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
GI
MA
EM
LC
FE
AT
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PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSIS Ð GENERAL DESCRIPTION
ECM Terminals and Reference Value (Cont'd)
EC-135

Diagnostic ProcedureNBEC0720
SEF613ZB
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
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IDX
TROUBLE DIAGNOSIS Ð SPECIFICATION VALUE
Diagnostic Procedure
EC-137

SEF615Z
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSIS Ð SPECIFICATION VALUE
Diagnostic Procedure (Cont'd)
EC-139

ECM Terminals and Reference ValueNBEC0648Specification 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)
26 L/BECM relay
(Self shutt-off)[Engine is running]
[Ignition switch ªOFFº]
IFor a few seconds after turning ignition switch
ªOFFº0 - 1.5V
[Ignition switch ªOFFº]
IA few seconds passed after turning ignition
switch ªOFFºBATTERY VOLTAGE
(11 - 14V)
43 R Ignition switch[Ignition switch ªOFFº]0V
[Ignition switch ªONº]BATTERY VOLTAGE
(11 - 14V)
48 B ECM ground[Engine is running]
IIdle speedEngine ground
[Probe this terminal with (±)
tester probe when measuring]
57 B ECM ground[Engine is running]
IIdle speedEngine ground
12
67W/RPower supply for ECM
(Buck-up)[Ignition switch ªOFFº]BATTERY VOLTAGE
(11 - 14V)
108 B ECM ground[Engine is running]
IIdle speedEngine ground
11 0
11 2B/W
B/WPower supply for ECM[Ignition switch ªONº]BATTERY VOLTAGE
(11 - 14V)
GI
MA
EM
LC
FE
AT
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
TROUBLE DIAGNOSIS FOR POWER SUPPLY
ECM Terminals and Reference Value
EC-141