2008 NISSAN TEANA power steering

EC-90
< FUNCTION DIAGNOSIS >[VQ25DE, VQ35DE]
INTAKE VALVE TIMING CONTROL
1. A/F sensor 1 (bank 1) harness con-
nector2. A/F sensor 1 (bank 1) 3. A/F sensor 1 (bank 2) harness con-
nector
4. A/F sensor 1 (bank 2)
: Vehicle front
1. HO2S2 (bank 1) 2. HO2S2 (bank 2) 3. HO2S2 (bank 2) harness connector
4. Tie-rod (RH) 5. Power steering pressure sensor 6. HO2S2 (bank 1) harness connector
: Vehicle front
1. Electronic controlled engine mount
control solenoid valve2. VIAS control solenoid valve 1 3. VIAS control solenoid valve 2
4. EVAP canister purge volume control
solenoid valve
JMBIA1116ZZ
JMBIA1380ZZ
JMBIA1381GB

VARIABLE INDUCTION AIR SYSTEM
EC-99
< FUNCTION DIAGNOSIS >[VQ25DE, VQ35DE]
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1. A/F sensor 1 (bank 1) harness con-
nector2. A/F sensor 1 (bank 1) 3. A/F sensor 1 (bank 2) harness con-
nector
4. A/F sensor 1 (bank 2)
: Vehicle front
1. HO2S2 (bank 1) 2. HO2S2 (bank 2) 3. HO2S2 (bank 2) harness connector
4. Tie-rod (RH) 5. Power steering pressure sensor 6. HO2S2 (bank 1) harness connector
: Vehicle front
1. Electronic controlled engine mount
control solenoid valve2. VIAS control solenoid valve 1 3. VIAS control solenoid valve 2
4. EVAP canister purge volume control
solenoid valve
JMBIA1116ZZ
JMBIA1380ZZ
JMBIA1381GB

EC-114
< FUNCTION DIAGNOSIS >[VQ25DE, VQ35DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
 1st trip freeze frame data
 System readiness test (SRT) codes
Test values
ENGINE CONTROL COMPONENT PARTS/CONTROL SYSTEMS APPLICATION
ItemDIAGNOSTIC TEST MODE
WORK
SUPPORTSELF-DIAGNOSTIC
RESULTS
DATA
MONI-
TORACTIVE
TESTDTC & SRT
CONFIRMATION
DTC*
1FREEZE
FRAME
DATA*
2
SRT STA-
TUSDTC
WORK
SUP-
PORT
ENGINE CONTROL COMPONENT PARTS
INPUT
Crankshaft position sensor (POS)×××
Camshaft position sensor (PHASE)×××
Mass air flow sensor××
Engine coolant temperature sensor××××
Engine oil temperature sensor×
Air fuel ratio (A/F) sensor 1××××
Heated oxygen sensor 2××××
Vehicle speed signal×××
Accelerator pedal position sensor××
Throttle position sensor×××
Intake air temperature sensor××
Knock sensor×
Refrigerant pressure sensor×
Closed throttle position switch (accel-
erator pedal position sensor signal)×
Air conditioner switch×
Park/neutral position (PNP) signal××
Stop lamp switch××
Power steering pressure sensor××
Battery voltage×
Load signal×
Primary speed sensor××
Battery current sensor××
ASCD steering switch××
ASCD brake switch××

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-117
< FUNCTION DIAGNOSIS >[VQ25DE, VQ35DE]
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COOLAN TEMP/S°C or °F The engine coolant temperature (determined by
the signal voltage of the engine coolant tempera-
ture sensor) is displayed. When the engine coolant temperature
sensor is open or short-circuited,
ECM enters fail-safe mode. The en-
gine coolant temperature determined
by the ECM is displayed.
A/F SEN1 (B1)
V The A/F signal computed from the input signal of
the air fuel ratio (A/F) sensor 1 is displayed.
A/F SEN1 (B2)
HO2S2 (B1)
V The signal voltage of the heated oxygen sensor 2
is displayed.
HO2S2 (B2)
HO2S2 MNTR(B1)
RICH/LEAN Display of heated oxygen sensor 2 signal:
RICH: means the amount of oxygen after three
way catalyst is relatively small.
LEAN: means the amount of oxygen after three
way catalyst is relatively large. When the engine is stopped, a certain
value is indicated.
HO2S2 MNTR(B2)
VHCL SPEED SE km/h or mph The vehicle speed computed from the vehicle
speed signal sent from combination meter is dis-
played.
BATTERY VOLT V  The power supply voltage of ECM is displayed.
ACCEL SEN 1
V The accelerator pedal position sensor signal volt-
age is displayed. ACCEL SEN 2 signal is converted by
ECM internally. Thus, it differs from
ECM terminal voltage signal. ACCEL SEN 2
TP SEN 1-B1
V The throttle position sensor signal voltage is dis-
played. TP SEN 2-B1 signal is converted by
ECM internally. Thus, it differs from
ECM terminal voltage signal. TP SEN 2-B1
INT/A TEMP SE°C or °F The intake air temperature (determined by the
signal voltage of the intake air temperature sen-
sor) is indicated.
START SIGNAL ON/OFF Indicates start signal status [ON/OFF] computed
by the ECM according to the signals of engine
speed and battery voltage. After starting the engine, [OFF] is dis-
played regardless of the starter sig-
nal.
CLSD THL POS ON/OFF Indicates idle position [ON/OFF] computed by
ECM according to the accelerator pedal position
sensor signal.
AIR COND SIG ON/OFF Indicates [ON/OFF] condition of the air condition-
er switch as determined by the air conditioner sig-
nal.
P/N POSI SW ON/OFF Indicates [ON/OFF] condition from the park/neu-
tral position (PNP) signal.
PW/ST SIGNAL ON/OFF [ON/OFF] condition of the power steering system
(determined by the signal voltage of the power
steering pressure sensor) 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 position.
OFF: Both rear window defogger switch and light-
ing switch are OFF.
IGNITION SW ON/OFF Indicates [ON/OFF] condition from ignition switch
signal.
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 sig-
nals. When the engine is stopped, a certain
computed value is indicated.
INJ PULSE-B2Monitored item Unit Description Remarks

TROUBLE DIAGNOSIS - SPECIFICATION VALUE
EC-129
< COMPONENT DIAGNOSIS >[VQ25DE, VQ35DE]
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2. Disconnect ECM harness connector. Check pin terminal and connector for damage, and then reconnect it.
>> GO TO 16.
16.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F ALPHA-B2” in “SPEC” of “DATA MONITOR” mode, and check that the each
indication is within the SP value.
Is the measurement value within the SP value?
YES >> INSPECTION END
NO >> Detect malfunctioning part according to EC-400, "
Symptom Table".
17.CHECK “B/FUEL SCHDL”
Select “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and check that the indication is within the SP
value.
Is the measurement value within the SP value?
YES >> INSPECTION END
NO-1 >> More than the SP value: GO TO 18.
NO-2 >> Less than the SP value: GO TO 25.
18.DETECT MALFUNCTIONING PART
1. Check for the cause of large engine friction. Refer to the following.
- Engine oil level is too high
- Engine oil viscosity
- Belt tension of power steering, alternator, A/C compressor, etc. is excessive
- Noise from engine
- Noise from transmission, etc.
2. Check for the cause of insufficient combustion. Refer to the following.
- Valve clearance malfunction
- Intake valve timing control function malfunction
- Camshaft sprocket installation malfunction, etc.
>> Repair or replace malfunctioning part, and then GO TO 30.
19.CHECK INTAKE SYSTEM
Check for the cause of uneven air flow through mass air flow sensor. Refer to the following.
 Crushed air ducts
 Malfunctioning seal of air cleaner element
 Uneven dirt of air cleaner element
 Improper specification of intake air system
Is the inspection result normal?
YES >> GO TO 21.
NO >> Repair or replace malfunctioning part, and then GO TO 20.
20.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”, AND “B/FUEL SCHDL”
Select “A/F ALPHA-B1”, “A/F ALPHA-B2”, and “B/FUEL SCHDL” in “SPEC” of “DATA MONITOR” mode, and
check that each indication is within the SP value.
Is the measurement value within the SP value?
YES >> INSPECTION END
NO >> “B/FUEL SCHDL” is more, “A/F ALPHA-B1”, “A/F ALPHA-B2” are less than the SP value: GO TO
21.
21.DISCONNECT AND RECONNECT MASS AIR FLOW SENSOR HARNESS CONNECTOR
1. Stop the engine.
2. Disconnect mass air flow sensor harness connector. Check pin terminal and connector for damage and
then reconnect it again.
>> GO TO 22.

EC-236
< COMPONENT DIAGNOSIS >[VQ25DE, VQ35DE]
P0550 PSP SENSOR
P0550 PSP SENSOR
DescriptionINFOID:0000000003856695
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.
DTC LogicINFOID:0000000003856696
DTC DETECTION LOGIC
NOTE:
If DTC P0550 is displayed with DTC P0643, first perform the trouble diagnosis for DTC P0643. Refer to
EC-243, "
DTC Logic".
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Start engine and let it idle for at least 5 seconds.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-236, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000003856697
1.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connection E38. Refer to Ground Inspection in GI-37, "
Circuit Inspection".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace ground connection.
2.CHECK PSP SENSOR POWER SUPPLY CIRCUIT
1. Disconnect power steering pressure (PSP) sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between PSP sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 3.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0550Power steering pressure
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
PSP sensor
Ground Voltage
Connector Terminal
F62 3 Ground Approx. 5 V

P0550 PSP SENSOR
EC-237
< COMPONENT DIAGNOSIS >[VQ25DE, VQ35DE]
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3.CHECK PSP SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between PSP sensor harness connector and ECM harness connector.
4. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 4.
NO >> Repair open circuit or short to ground short to power in harness or connectors.
4.CHECK PSP SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check the continuity between PSP sensor harness connector and ECM harness connector.
2. Also check harness for short to ground and short to power.
Is the inspection result normal?
YES >> GO TO 5.
NO >> Repair open circuit, short to ground or short to power in harness or connectors.
5.CHECK PSP SENSOR
Refer to EC-237, "
Component Inspection".
Is the inspection result normal?
YES >> GO TO 6.
NO >> Replace PSP sensor.
6.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000003856698
1.CHECK POWER STEERING PRESSURE SENSOR
1. Reconnect all harness connectors disconnected.
2. Start engine and let it idle.
3. Check the voltage between ECM terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace power steering pressure sensor.
PSP sensor ECM
Continuity
Connector Terminal Connector Terminal
F62 1 F8 48 Existed
PSP sensor ECM
Continuity
Connector Terminal Connector Terminal
F62 2 F8 41 Existed
ECM
Condition Voltage
Connector+–
Te r m i n a l Te r m i n a l
F841
(Power steering pressure
sensor signal)48
(Sensor ground)Steering wheel: Being turned. 0.5 - 4.5 V
Steering wheel: Not being turned. 0.4 - 0.8 V

P0643 SENSOR POWER SUPPLY
EC-243
< COMPONENT DIAGNOSIS >[VQ25DE, VQ35DE]
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P0643 SENSOR POWER SUPPLY
DTC LogicINFOID:0000000003856708
DTC DETECTION LOGIC
DTC CONFIRMATION PROCEDURE
1.PRECONDITIONING
If DTC Confirmation Procedure has been previously conducted, always turn ignition switch OFF and wait at
least 10 seconds before conducting the next test.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 8 V at idle.
>> GO TO 2.
2.PERFORM DTC CONFIRMATION PROCEDURE
1. Turn ignition switch ON.
2. Start engine and let it idle for 1 second.
3. Check DTC
Is DTC detected?
YES >> Go to EC-243, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000003856709
1.CHECK GROUND CONNECTION
1. Turn ignition switch OFF.
2. Check ground connection E38. Refer to Ground Inspection in GI-37, "
Circuit Inspection".
Is the inspection result normal?
YES >> GO TO 2.
NO >> Repair or replace ground connection.
2.CHECK ACCELERATOR PEDAL POSITION SENSOR 1 POWER SUPPLY CIRCUIT
1. Disconnect accelerator pedal position (APP) sensor harness connector.
2. Turn ignition switch ON.
3. Check the voltage between APP sensor harness connector and ground.
Is the inspection result normal?
YES >> GO TO 7.
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0643Sensor power supply
circuit shortECM detects that the voltage of power
source for sensor is excessively low or high. Harness or connectors
(APP sensor 1 circuit is shorted.)
(TP sensor circuit is shorted.)
[CMP sensor (PHASE) circuit is shorted.)
(PSP sensor circuit is shorted.)
(Battery current sensor circuit is shorted.)
 Accelerator pedal position sensor
 Throttle position sensor
 Camshaft position sensor (PHASE)
 Power steering pressure sensor
 Battery current sensor
APP sensor
Ground Voltage (V)
Connector Terminal
E110 4 Ground Approx. 5