2001 NISSAN X-TRAIL power steering

DTC P0550 PSP SENSOR
EC-983
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DTC P0550 PSP SENSORPFP:49763
Component DescriptionEBS00MY9
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 ModeEBS00MYA
Specification data are reference values.
ECM Terminals and Reference ValueEBS00MYB
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 LogicEBS00MYC
The MI will not light up for this diagnosis.
DTC Confirmation ProcedureEBS00MYD
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”.
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 RSensor's power sup-
ply[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-987
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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-987, "
Component Inspection" .
OK or NG
OK >> GO TO 6.
NG >> Replace PSP sensor.
6.CHECK INTERMITTENT INCIDENT
Refer to EC-847, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
Component InspectionEBS00MYG
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-1129
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System ChartEBS00N3G
*1: This sensor is not used to control the engine system under normal conditions.
*2: These signals are sent to the ECM through CAN communication line.
Multiport Fuel Injection (MFI) SystemEBS00N3H
INPUT/OUTPUT SIGNAL CHART
*1: Under normal conditions, this sensor is not for engine control operation.
*2: This signal is sent to the ECM through CAN communication line. Input (Sensor) ECM Function Output (Actuator)
●Camshaft position sensor (PHASE)
●Crankshaft position sensor (POS)
●Mass air flow sensor
●Engine coolant temperature sensor
●Heated oxygen sensor 1
●Throttle position sensor
●Accelerator pedal position sensor
●Park/neutral position (PNP) switch
●Intake air temperature sensor
●Power steering pressure sensor
●Ignition switch
●Battery voltage
●Knock sensor
●Refrigerant pressure sensor
●Heated oxygen sensor 2 *1
●TCM (Transmission control module) *2
●ESP/TCS/ABS control unit *2
●Wheel sensor
●Air conditioner switch
●Electrical loadFuel injection & mixture ratio control Fuel injectors
Electronic ignition system Power transistors
Fuel pump control Fuel pump relay
On board diagnostic system MI (On the instrument panel)
Heated oxygen sensor 1 heater control Heated oxygen sensor 1 heater
Heated oxygen sensor 2 heater control Heated oxygen sensor 2 heater
EVAP canister purge flow controlEVAP canister purge volume control
solenoid valve
Air conditioning cut control Air conditioner relay
Cooling fan control Cooling fan relays
Sensor Input Signal to ECMECM
functionActuator
Crankshaft position sensor (POS)
Engine speed
Piston position
Fuel injec-
tion & mix-
ture ratio
controlFuel injectors Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Heated oxygen sensor 1 Density of oxygen in exhaust gas
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Park/neutral position (PNP) switch Gear position
Ignition switch Start signal
Knock sensor Engine knocking condition
Battery Battery voltage
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2 *
1Density of oxygen in exhaust gas
ESP/TCS/ABS control unit *
2ESP/TCS operation command
Wheel sensor Vehicle speed
Air conditioner switch Air conditioner operation

EC-1132
[QR20(WITHOUT EURO-OBD)]
ENGINE CONTROL SYSTEM
Electronic Ignition (EI) System
EBS00N3I
INPUT/OUTPUT SIGNAL CHART
SYSTEM DESCRIPTION
The ignition timing is controlled by the ECM to maintain the best air-
fuel ratio for every running condition of the engine. The ignition tim-
ing data is stored in the ECM. This data forms the map shown.
The ECM receives information such as the injection pulse width and
camshaft position sensor signal. Computing this information, ignition
signals are transmitted to the power transistor.
e.g., N: 1,800 rpm, Tp: 1.50 msec
A°BTDC
During the following conditions, the ignition timing is revised by the
ECM according to the other data stored in the ECM.
●At starting
●During warm-up
●At idle
●At low battery voltage
●During acceleration
The knock sensor retard system is designed only for emergencies. The basic ignition timing is programmed
within the anti-knocking zone, if recommended fuel is used under dry conditions. The retard system does not
operate under normal driving conditions. If engine knocking occurs, the knock sensor monitors the condition.
The signal is transmitted to the ECM. The ECM retards the ignition timing to eliminate the knocking condition.
Air Conditioning Cut ControlEBS00N3J
INPUT/OUTPUT SIGNAL CHART
SYSTEM DESCRIPTION
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned off.
Sensor Input Signal to ECMECM
functionActuator
Crankshaft position sensor (POS)
Engine speed
Piston position
Ignition
timing con-
trolPower transistor Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Ignition switch Start signal
Knock sensor Engine knocking
Park/neutral position (PNP) switch Gear position
Battery Battery voltage
Wheel sensor Vehicle speed
SEF742M
Sensor Input Signal to ECM ECM function Actuator
Air conditioner switch Air conditioner “ON” signal
Air conditioner
cut controlAir conditioner relay Throttle position sensor Throttle valve opening angle
Crankshaft position sensor (POS) Engine speed
Engine coolant temperature sensor Engine coolant temperature
Ignition switch Start signal
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensor Vehicle speed

ENGINE CONTROL SYSTEM
EC-1133
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●When the accelerator pedal is fully depressed.
●When cranking the engine.
●At high engine speeds.
●When the engine coolant temperature becomes excessively high.
●When operating power steering during low engine speed or low vehicle speed.
●When engine speed is excessively low.
●When refrigerant pressure is excessively low or high.
Fuel Cut Control (at No Load and High Engine Speed)EBS00N3K
INPUT/OUTPUT SIGNAL CHART
SYSTEM DESCRIPTION
If the engine speed is above 1,800 rpm with no load (for example, in neutral and engine speed over 1,800
rpm) fuel will be cut off after some time. The exact time when the fuel is cut off varies based on engine speed.
Fuel cut will operate until the engine speed reaches 1,500 rpm, then fuel cut is cancelled.
NOTE:
This function is different from deceleration control listed under “Multiport Fuel Injection (MFI) System”, EC-
11 2 9 .
CAN CommunicationEBS00NBF
SYSTEM DESCRIPTION
CAN (Controller Area Network) is a serial communication line for real time application. It is an on-vehicle mul-
tiplex communication line with high data communication speed and excellent error detection ability. Many elec-
tronic control units are equipped onto a vehicle, and each control unit shares information and links with other
control units during operation (not independent). In CAN communication, control units are connected with 2
communication lines (CAN H line, CAN L line) allowing a high rate of information transmission with less wiring.
Each control unit transmits/receives data but selectively reads required data only.
FOR A/T MODELS
System diagram
Input/output signal chart
T: Transmit R: Receive Sensor Input Signal to ECMECM
functionActuator
Park/neutral position (PNP) switch Neutral position
Fuel cut
controlFuel injectors Throttle position sensor Throttle position
Accelerator pedal position sensor Accelerator pedal position
Engine coolant temperature sensor Engine coolant temperature
Crankshaft position sensor (POS) Engine speed
Wheel sensor Vehicle speed
SKIA0884E
Signals ECM TCM
Engine coolant temperature signal T R
Accelerator pedal position signal T R
A/T self-diagnosis signal R T

TROUBLE DIAGNOSIS
EC-1151
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Fail-safe ChartEBS00N3Y
The ECM enters fail-safe mode, if any of the following malfunctions is detected due to the open or short circuit.
When the ECM enters the fail-safe mode, the MI illuminates.
Priority Detected items (DTC)
1
●U1000 CAN communication line
●P0102 P0103 Mass air flow sensor
●P0117 P0118 Engine coolant temperature sensor
●P0120 Throttle position sensor
●P0121 Accelerator pedal position sensor
●P0327 P0328 Knock sensor
●P0335 Crankshaft position sensor (POS)
●P0340 Camshaft position sensor (PHASE)
●P0500 Vehicle speed sensor
●P0605 ECM
2
●P0134 Heated oxygen sensor 1
●P0550 Power steering pressure sensor
●P0650 MI
●P1065 ECM power supply
●P1122 Electric throttle control function
●P1123 Throttle control motor relay
●P1212 ESP/TCS/ABS communication line
●P1805 Brake switch
3
●P1121 Electric throttle control actuator
●P1217 Engine over temperature (OVERHEAT)
DTC No. Detected items Engine operating condition in fail-safe mode
P0102
P0103Mass air flow sensor circuit Engine speed will not rise more than 2,400 rpm due to the fuel cut.
P0117
P0118Engine coolant tempera-
ture sensor circuitEngine coolant temperature will be determined by ECM based on the time after turning
ignition switch “ON” or “START”.
CONSULT-II displays the engine coolant temperature decided by ECM.
ConditionEngine coolant temperature decided (CONSULT-
II display)
Just as ignition switch is turned
ON or Start40°C (104°F)
More than approx. 4 minutes after
ignition ON or Start80°C (176°F)
Except as shown above40 - 80°C (104 - 176°F)
(Depends on the time)
When the fail-safe system for engine coolant temperature sensor is activated, the cool-
ing fan operates while engine is running.
P0120 Throttle position sensor cir-
cuitECM controls the electric throttle control actuator by regulating the throttle opening to
small range.
Therefore, acceleration will be poor.
Condition Driving condition
When engine is idling Normal
When accelerating Poor acceleration

TROUBLE DIAGNOSIS
EC-1157
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1 - 6: The numbers refer to the order of inspection.
(continued on next page)Air Positive crankcase ventilation sys-
tem334444444 41EC-1389
Incorrect idle speed adjustment 3 3 1 1 1 1 1EC-1152
Electric throttle control actuator 112332222 2 2EC-1273
,
EC-1275
,
EC-1281
IgnitionIncorrect ignition timing adjustment33111 11 1EC-1152
Ignition circuit 11222 22 2EC-1331
Main power supply and ground circuit22333 33 23EC-1193
Mass air flow sensor circuit 11222 22 2EC-1202
Engine coolant temperature sensor circuit 11222322312EC-1209
Throttle position sensor circuit 12 22222 2EC-1214
Accelerator pedal position sensor circuit 3 2 1 2 2EC-1222
Heated oxygen sensor 1 circuit1232 22 2EC-1229,
EC-1320
Knock sensor circuit 2 2 3EC-1235
Crankshaft position sensor (POS) circuit 2 2EC-1240
Camshaft position sensor (PHASE) circuit 2 2EC-1246
Vehicle speed signal circuit 2 3 3 3EC-1252
Power steering pressure sensor circuit 2 3 3 3 3EC-1257
ECM 22333333333EC-1262,
EC-1269
Intake valve timing control solenoid valve cir-
cuit332 13223 3EC-1347
PNP switch circuit 3 33333 3EC-1353
Start signal circuit 2EC-1362
Refrigerant pressure sensor circuit 2 3 3 3 3 4EC-1373
Electrical load signal circuit 3 3 3 3EC-1377
Air conditioner circuit223333333 3 2AT C - 3 3
SYMPTOM
Reference
page
HARD/NO START/RESTART (EXCP. HA)
ENGINE STALL
HESITATION/SURGING/FLAT SPOT
SPARK KNOCK/DETONATION
LACK OF POWER/POOR ACCELERATION
HIGH IDLE/LOW IDLE
ROUGH IDLE/HUNTING
IDLING VIBRATION
SLOW/NO RETURN TO IDLE
OVERHEATS/WATER TEMPERATURE HIGH
EXCESSIVE FUEL CONSUMPTION
EXCESSIVE OIL CONSUMPTION
BATTERY DEAD (UNDER CHARGE)
Warranty symptom code AA AB AC AD AE AF AG AH AJ AK AL AM HA

EC-1170
[QR20(WITHOUT EURO-OBD)]
TROUBLE DIAGNOSIS
65 RSensor's power sup-
ply[Ignition switch “ON”]Approximately 5V
66 W/LPower supply for
ECM (Buck-up)[Ignition switch “OFF”]BATTERY VOLTAGE
(11 - 14V)
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
71 PU/RCrankshaft position
sensor (POS)[Engine is running]
●Warm-up condition
●Idle speedApproximately 3V
[Engine is running]
●Engine speed is 2,000 rpmApproximately 3V
72 OR Mass air flow sensor[Engine is running]
●Warm-up condition
●Idle speed1.1 - 1.5V
[Engine is running]
●Warm-up condition
●Engine speed is 2,500 rpm.1.6 - 2.0V
73 WThrottle position sen-
sor 1[Ignition switch “ON”]
●Gear position is “D” (A/T model)
●Gear position is “1st” (M/T model)
●Accelerator pedal fully releasedMore than 0.36V
[Ignition switch “ON”]
●Gear position is “D” (A/T model)
●Gear position is “1st” (M/T model)
●Accelerator pedal fully depressedLess than 4.75V
74 GThrottle position sen-
sor 2[Ignition switch “ON”]
●Gear position is “D” (A/T model)
●Gear position is “1st” (M/T model)
●Accelerator pedal fully releasedLess than 4.75V
[Ignition switch “ON”]
●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)
PBIB0527E
PBIB0528E