2001 NISSAN X-TRAIL power steering

EC-1174
[QR20(WITHOUT EURO-OBD)]
TROUBLE DIAGNOSIS
ENGINE CONTROL COMPONENT PARTS/CONTROL SYSTEMS APPLICATION
X: Applicable
*1: This item includes 1st trip DTCs.
*2: This mode includes 1st trip freeze frame data or freeze frame data. The items appear on CONSULT-II screen in freeze frame data
mode only if a 1st trip DTC or DTC is detected. For details, refer to EC-1142
.
CONSULT-II INSPECTION PROCEDURE
1. Turn ignition switch OFF.
ItemDIAGNOSTIC TEST MODE
WORK
SUPPORTSELF-DIAGNOSTIC
RESULTS
DATA
MONI-
TORDATA
MONI-
TOR
(SPEC)ACTIVE
TEST
DTC*1FREEZE
FRAME
DATA*2
ENGINE CONTROL COMPONENT PARTS
INPUT
Crankshaft position sensor (POS)××××
Camshaft position sensor (PHASE)×
Mass air flow sensor×××
Engine coolant temperature sensor×××××
Heated oxygen sensor 1×××
Heated oxygen sensor 2××
Wheel sensor (Vehicle speed signal)××××
Accelerator pedal position sensor×××
Throttle position sensor×××
Intake air temperature sensor××
Knock sensor×
Refrigerant pressure sensor××
Ignition switch (start signal)××
Closed throttle position switch (accelera-
tor pedal position sensor signal)××
Air conditioner switch××
Park/neutral position (PNP) switch××
Stop lamp switch×××
Power steering pressure sensor×××
Battery voltage××
Load signal××
ENGINE CONTROL COMPONENT PARTS
OUTPUT
Injectors×× ×
Power transistor (Ignition timing)×× ×
Throttle control motor relay×××
EVAP canister purge volume control sole-
noid valve×× ×
Air conditioner relay××
Fuel pump relay××××
Cooling fan relay××××
Heated oxygen sensor 1 heater××
Heated oxygen sensor 2 heater××
Intake valve timing control solenoid valve×× ×
Calculated load value×××

EC-1178
[QR20(WITHOUT EURO-OBD)]
TROUBLE DIAGNOSIS
CLSD THL POS
[ON/OFF]××●Indicates idle position [ON/OFF] com-
puted by ECM according to the acceler-
ator pedal position sensor signal.
AIR COND SIG
[ON/OFF]××
●Indicates [ON/OFF] condition of the air
conditioner switch as determined by the
air conditioner signal.
P/N POSI SW
[ON/OFF]××
●Indicates [ON/OFF] condition from the
park/neutral position (PNP) switch sig-
nal.
PW/ST SIGNAL
[ON/OFF]××
●[ON/OFF] condition of the power steer-
ing system (determined by the signal
voltage of the power steering pressure
sensor signal) is indicated.
LOAD SIGNAL
[ON/OFF]××
●Indicates [ON/OFF] condition from the
electrical load signal.
ON ... Rear window defogger switch is
ON and/or lighting switch is in 2nd posi-
tion.
OFF ... Both rear window defogger
switch and lighting switch are OFF.
IGNITION SW
[ON/OFF]××
●Indicates [ON/OFF] condition from igni-
tion switch.
HEATER FAN SW
[ON/OFF]×
●Indicates [ON/OFF] condition from the
heater fan switch signal.
BRAKE SW
[ON/OFF]×
●Indicates [ON/OFF] condition from the
stop lamp switch signal.
INJ PULSE-B1
[msec]×
●Indicates the actual fuel injection pulse
width compensated by ECM according
to the input signals.●When the engine is stopped, a
certain computed value is indi-
cated.
B/FUEL SCHDL
[msec]×
●“Base fuel schedule” indicates the fuel
injection pulse width programmed into
ECM, prior to any learned on board cor-
rection.
IGN TIMING
[BTDC]×
●Indicates the ignition timing computed
by ECM according to the input signals.●When the engine is stopped, a
certain value is indicated.
A/F ALPHA-B1 [%]×
●The mean value of the air-fuel ratio
feedback correction factor per cycle is
indicated.
●When the engine is stopped, a
certain value is indicated.
●This data also includes the data
for the air-fuel ratio learning con-
trol.
CAL/LD VALUE [%]
●“Calculated load value” indicates the
value of the current airflow divided by
peak airflow.
MASS AIRFLOW
[g·m/s]
●Indicates the mass airflow computed by
ECM according to the signal voltage of
the mass air flow sensor.
PURG VOL C/V
[%]
●Indicates the EVAP canister purge vol-
ume control solenoid valve control value
computed by the ECM according to the
input signals.
●The opening becomes larger as the
value increases. Monitored item
[Unit]ECM
INPUT
SIG-
NALSMAIN
SIG-
NALSCAN
DIAG
SUP-
PORT
MNTRDescription Remarks

DTC P0120 TP SENSOR
EC-1215
[QR20(WITHOUT EURO-OBD)]
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EC
On Board Diagnosis LogicEBS00N56
FAIL-SAFE MODE
ECM enters fail-safe mode when the malfunction A, B, C or D is detected.
*: The ECM enters in the fail-safe mode when the normal signal is entered to the ECM after the malfunction C was detected.
DTC Confirmation ProcedureEBS00N57
NOTE:
●Perform “PROCEDURE FOR MALFUNCTION A, B, C AND D” first. If the 1st trip DTC cannot be con-
firmed, perform “PROCEDURE FOR MALFUNCTION E”. If the 1st trip DTC cannot be confirmed,
perform “PROCEDURE FOR MALFUNCTION F.
74 GThrottle position sen-
sor 2[Ignition switch “ON”]
●Engine stopped
●Gear position is “D” (A/T model)
●Gear position is “1st” (M/T model)
●Accelerator pedal fully releasedLess than 4.75V
[Ignition switch “ON”]
●Engine stopped
●Gear position is “D” (A/T model)
●Gear position is “1st” (M/T model)
●Accelerator pedal fully depressedMore than 0.36V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0120
0120Throttle position sensor
circuitA)An excessively low or high voltage from
the throttle position sensor 1 is sent to
ECM.
●Harness or connectors
(The throttle position sensor 1 or 2 circuit
is open or shorted.)
●Electric throttle control actuator B)An excessively low or high voltage from
the throttle position sensor 2 is sent to
ECM.
C)A difference between signals from sensor
1 and sensor 2 is out of the specified
range.
D)ECM detects a voltage of power source
for sensor is excessively low or high.
●Harness or connectors
(The throttle position sensor 1, 2, accel-
erator pedal position sensor 1, 2, mass
air flow sensor, power steering pressure
sensor or refrigerant pressure sensor cir-
cuit is shorted.)
●ECM
(ECM pin terminal is bend or break.)
E)Closed throttle position learning value is
excessively low.
●Electric throttle control actuator
F)Closed throttle position learning is not
performed successfully, repeatedly.
Detected items Engine operation condition in fail-safe mode
Malfunction A The ECM controls the electric throttle control actuator in regulating the throttle opening in order for the idle
position to be within +10 degrees.
The ECM regulates the opening speed of the throttle valve to be slower than the normal condition.
So, the acceleration will be poor. Malfunction B
Malfunction C*
Malfunction DECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx.
5 degrees) by the return spring.

DTC P0120 TP SENSOR
EC-1219
[QR20(WITHOUT EURO-OBD)]
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EC
Diagnostic ProcedureEBS00N59
MALFUNCTIONING A, B, C, AND D
1.RETIGHTEN GROUND SCREWS
1. Turn ignition switch “OFF”.
2. Loosen and retighten engine ground screws.
>> GO TO 2.
2.CHECK THROTTLE POSITION SENSOR POWER SUPPLY CIRCUIT
1. Disconnect electric throttle control actuator harness connector.
2. Turn ignition switch “ON”.
3. Check voltage between electric throttle control actuator terminal
1 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 4.
NG >> GO TO 3.
3.DETECT MALFUNCTIONING PART
Check the following.
●Harness for short between ECM and electric throttle control actuator
●Harness for short between ECM and accelerator pedal position sensor
●Harness for short between ECM and mass air flow sensor
●Harness for short between ECM and power steering pressure sensor
●Harness for short between ECM and refrigerant pressure sensor
●ECM pin terminal
>> Repair short to ground or short to power in harness or connectors.
PBIB0494E
PBIB0497E
Voltage: Approximately 5V
PBIB0082E

DTC P0550 PSP SENSOR
EC-1257
[QR20(WITHOUT EURO-OBD)]
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EC
DTC P0550 PSP SENSORPFP:49763
Component DescriptionEBS00N6Q
Power steering pressure (PSP) sensor is installed to the power
steering high-pressure tube and detects a power steering load. This
sensor is a potentiometer which transforms the power steering load
into output voltage, and emits the voltage signal to the ECM. The
ECM controls the electric throttle control actuator and adjusts the
throttle valve opening angle to increase the engine speed and
adjusts the idle speed for the increased load.
CONSULT-II Reference Value in Data Monitor ModeEBS00N6R
Specification data are reference values.
ECM Terminals and Reference ValueEBS00N6S
Specification 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.
On Board Diagnosis LogicEBS00N6T
The MI will not light up for this diagnosis.
DTC Confirmation ProcedureEBS00N6U
NOTE:
If “DTC Confirmation Procedure” has been previously conducted, always turn ignition switch “OFF” and wait at
least 10 seconds before conducting the next test.
WITH CONSULT-II
1. Turn ignition switch "ON".
2. Select "DATA MONITOR" mode with CONSULT-II.
PBIB0502E
MONITOR ITEM CONDITION SPECIFICATION
PW/ST SIGNAL
●Engine: After warming up, idle
the engineSteering wheel is in neutral position.
(Forward direction)OFF
Steering wheel is turned. ON
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
58 B Sensors' ground[Engine is running]
●Warm-up condition
●Idle speedApproximately 0V
65 R Sensor's power supply[Ignition switch “ON”]Approximately 5V
67 PPower steering pres-
sure sensor[Engine is running]
●Steering wheel is being turned.0.5 - 4.0V
[Engine is running]
●Steering wheel is not being turned.0.4 - 0.8V
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0550
0550Power steering pres-
sure sensor circuitAn excessively low or high voltage from the
sensor is sent to ECM.
●Harness or connectors
(The sensor circuit is open or shorted)
●Power steering pressure sensor

DTC P0550 PSP SENSOR
EC-1261
[QR20(WITHOUT EURO-OBD)]
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EC
4.CHECK PSP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 67 and PSP sensor terminal 2.
3. Also check harness for short to ground and short to power.
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 PSP SENSOR
Refer to EC-1261, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace PSP sensor.
6.CHECK INTERMITTENT INCIDENT
Refer to EC-1192, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionEBS00N6X
POWER STEERING PRESSURE SENSOR
1. Reconnect all harness connectors disconnected.
2. Start engine and let it idle.
3. Check voltage between ECM terminal 67 and ground under the
following conditions.Continuity should exist.
Condition Voltage
Steering wheel is being turned fully. Approximately 3.6V
Steering wheel is not being turned. Approximately 0.6V
PBIB0570E

ENGINE CONTROL SYSTEM
EC-1399
[YD]
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EC
System ChartEBS0037B
*: The input signals are sent to the ECM through CAN communication line.
Fuel Injection Control SystemEBS0036G
SYSTEM DESCRIPTION
Three types of fuel injection control are provided to accommodate engine operating conditions; normal control,
idle control and start control. The ECM determines the appropriate fuel injection control. Under each control,
the amount of fuel injected is adjusted to improve engine performance.
Pulse signals are exchanged between ECM and Electronic Drive Unit (EDU). EDU controls fuel injectors
according to the input signals to adjust the amount of fuel injected to the preset value.
START CONTROL
Input/Output Signal Chart
When the ECM receives a start signal from the ignition switch, the
ECM adapts the fuel injection system for the start control. The
amount of fuel injected at engine starting is a preset program value
in the ECM. The program is determined by the engine speed, engine
coolant temperature and common rail fuel pressure.
For better startability under cool engine conditions, the lower the
coolant temperature becomes, the greater the amount of fuel
injected. The ECM ends the start control when the engine speed
reaches the specific value, and shifts the control to the normal or idle
control.
Input (Sensor) ECM Function Output (Actuator)
●Accelerator pedal position sensor
●Accelerator pedal released position switch
●Common rail fuel pressure sensor
●Fuel temperature sensor
●Engine coolant temperature sensor
●Crankshaft position sensor (TDC)
●Camshaft position sensor
●Vehicle speed sensor
●ESP/TCS/ABS control unit*
●Ignition switch
●Stop L amp s witch
●Air conditioner switch
●Mass air flow sensor
●Park/neutral position switch
●Battery voltage
●Power steering oil pressure switch Fuel injection controlEDU, Fuel injectors and Suction control
valve
Fuel injection timing controlEDU, Fuel injectors and Suction control
valve
Fuel cut controlEDU, Fuel injectors and Suction control
valve
Glow control system Glow relay & glow indictor lamp
On board diagnostic system Malfunction indicator (MI)
EGR volume control EGR volume control valve
Cooling fan control Cooling fan relay
Air conditioning cut control Air conditioner relay
Sensor Input Signal to ECM ECM Function Actuator
Engine coolant temperature sensor Engine coolant temperature
Fuel injection
control (start
control)EDU
Fuel injectors
Suction control valve Crankshaft position sensor (TDC) Engine speed
Camshaft position sensor Piston position
Ignition switch Start signal
Common rail fuel pressure sensor Common rail fuel pressure
SEF648S

TROUBLE DIAGNOSIS
EC-1431
[YD]
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EC
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
CONSULT-II FunctionEBS0037H
CONSULT-II INSPECTION PROCEDURE
1. Turn ignition switch OFF.
2. Connect CONSULT-II to data link connector, which is located
under the driver side dash panel.
3. Turn ignition switch ON.
E11 L CAN communication line[Ignition switch “ON”]Approximately 2.6 - 3.2V
Output voltage varies with the
communication status.
E12 P/BPower steering oil pres-
sure switch[Engine is running]
●Steering wheel is being turnedApproximately 0V
[Engine is running]
●Steering wheel is not being turnedBATTERY VOLTAGE
(11 - 14V)
E13 G/ORPark/Neutral position
switch[Ignition switch “ON”]
●Gear position is “Neutral” Approximately 0V
[Ignition switch “ON”]
●Except the above gear positionBATTERY VOLTAGE
(11 - 14V)
E16 G/W Suction control valve 2[Engine is running]
●Warm-up condition
●Idle speed0 - 12.5V
[Engine is running]
●Warm-up condition
●Engine speed is 2,000 rpm0 - 12.5V
E21 L/B Vehicle speed sensor[Engine is running]
●Lift up the vehicle
●In 2nd gear position
●Vehicle speed is 30 km/h (19 MPH)0 - 5V TERMI-
NAL
NO.WIRE
COLORITEM CONDITIONDATA
(DC Voltage and Pulse Signal)
PBIB0401E
PBIB0402E
PBIB0386E
PBIB0376E