power steering system INFINITI M35 2007 Factory Workshop Manual

EC-486
[VQ35DE]
DTC P0643 SENSOR POWER SUPPLY
Revision: 2007 April2007 M35/M45
DTC P0643 SENSOR POWER SUPPLYPFP:18919
On Board Diagnosis LogicNBS0052I
This self-diagnosis has the one trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM enters fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureNBS0052J
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.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
WITH CONSULT-II
1. Turn ignition switch ON.
2. Select “DATA MONITOR” mode with CONSULT-II.
3. Start engine and let it idle for 1 second.
4. If DTC is detected, go to EC-489, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “WITH CONSULT-II” above.
DTC No.Trouble diagnosis
nameDTC detecting condition Possible cause
P0643
0643Sensor power supply
circuit shortECM detects a voltage of power source for
sensor is excessively low or high.

Harness or connectors
(APP sensor 1 circuit is shorted.)
(EVAP control system pressure sensor is
shorted.)
(Refrigerant pressure sensor circuit is
shorted.)
(PSP sensor circuit is shorted.)
(Battery current sensor circuit is shorted.)

Accelerator pedal position sensor

EVAP control system pressure sensor

Refrigerant pressure sensor

Power steering pressure sensor

Battery current sensor
Engine operation condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) by the return
spring.
SEF058Y

EC-488
[VQ35DE]
DTC P0643 SENSOR POWER SUPPLY
Revision: 2007 April2007 M35/M45
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.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
48 BRSensor power supply
(EVAP control system pres-
sure sensor)[Ignition switch: ON]Approximately 5V
49 B/YSensor power supply
(Refrigerant pressure sen-
sor, Battery current sensor)[Ignition switch: ON]Approximately 5V
68 L/YSensor power supply
(Power steering pressure
sensor)[Ignition switch: ON]Approximately 5V
82 WSensor ground
(APP sensor 1)[Engine is running]

Warm-up condition

Idle speedApproximately 0V
83 PSensor ground
(APP sensor 2)[Engine is running]

Warm-up condition

Idle speedApproximately 0V
90 LSensor power supply
(APP sensor 1)[Ignition switch: ON]Approximately 5V
91 BRSensor power supply
(APP sensor 2)[Ignition switch: ON]Approximately 5V
98 RAccelerator pedal position
sensor 2[Ignition switch: ON]

Engine stopped

Accelerator pedal: Fully released0.20 - 0.55V
[Ignition switch: ON]

Engine stopped

Accelerator pedal: Fully depressed1.85 - 2.40V
106 LGAccelerator pedal position
sensor 1[Ignition switch: ON]

Engine stopped

Accelerator pedal: Fully released0.4 - 1.1V
[Ignition switch: ON]

Engine stopped

Accelerator pedal: Fully depressed3.7 - 4.8V

EC-490
[VQ35DE]
DTC P0643 SENSOR POWER SUPPLY
Revision: 2007 April2007 M35/M45
3. CHECK SENSOR POWER SUPPLY CIRCUITS
Check harness for short to power and short to ground, between the following terminals.
OK or NG
OK >> GO TO 4.
NG >> Repair short to ground or short to power in harness or connectors.
4. CHECK COMPONENTS
Check the following.

EVAP control system pressure sensor (Refer to EC-436, "Component Inspection" .)

Refrigerant pressure sensor (Refer to AT C - 9 7 , "COMPONENT INSPECTION" .)

Battery current sensor (Refer to EC-529, "Component Inspection" .)

Power steering pressure sensor (Refer to EC-478, "Component Inspection" .)
OK or NG
OK >> GO TO 7.
NG >> Replace malfunctioning component.
5. CHECK APP SENSOR
Refer to EC-622, "
Component Inspection" .
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6. REPLACE ACCELERATOR PEDAL ASSEMBLY
1. Replace accelerator pedal assembly.
2. Perform EC-86, "
Accelerator Pedal Released Position Learning" .
3. Perform EC-86, "
Throttle Valve Closed Position Learning" .
4. Perform EC-86, "
Idle Air Volume Learning" .
>>INSPECTION END
7. CHECK INTERMITTENT INCIDENT
Refer to EC-153, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
ECM terminal Sensor terminal Reference Wiring Diagram
90 APP sensor terminal 4EC-487
48 EVAP control system pressure sensor terminal 3EC-433
49Refrigerant pressure sensor terminal 1EC-705Battery current sensor terminal 1EC-526
68 PSP sensor terminal 1EC-475

ENGINE CONTROL SYSTEM
EC-733
[VK45DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2007 April2007 M35/M45
Multiport Fuel Injection (MFI) SystemNBS0059J
INPUT/OUTPUT SIGNAL CHART
*1: This sensor is not used to control the engine system under normal conditions.
*2: This signal is sent to the ECM through CAN communication line.
*3: ECM determines the start signal status by the signals of engine speed and battery voltage.
SYSTEM DESCRIPTION
The amount of fuel injected from the fuel injector is determined by the ECM. The ECM controls the length of
time the valve remains open (injection pulse duration). The amount of fuel injected is a program value in the
ECM memory. The program value is preset by engine operating conditions. These conditions are determined
by input signals (for engine speed and intake air) from the crankshaft position sensor (POS), camshaft position
sensor (PHASE) and the mass air flow sensor.
VARIOUS FUEL INJECTION INCREASE/DECREASE COMPENSATION
In addition, the amount of fuel injected is compensated to improve engine performance under various operat-
ing conditions as listed below.
<Fuel increase>

During warm-up

When starting the engine

During acceleration

Hot-engine operation

When selector lever is changed from N to D

High-load, high-speed operation
<Fuel decrease>

During deceleration

During high engine speed operation
Sensor Input Signal to ECM ECM function Actuator
Crankshaft position sensor (POS)
Engine speed*
3
Piston position
Fuel injection
& mixture ratio
controlFuel injector Camshaft position sensor (PHASE)
Mass air flow sensor Amount of intake air
Engine coolant temperature sensor Engine coolant temperature
Air fuel ratio (A/F) 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
Battery
Battery voltage*
3
Knock sensor Engine knocking condition
Power steering pressure sensor Power steering operation
Heated oxygen sensor 2*
1Density of oxygen in exhaust gas
ABS actuator and electric unit (control unit)
VDC/TCS operation command*
2
Air conditioner switch
Air conditioner operation*2
Wheel sensor
Vehicle speed*2

AIR CONDITIONING CUT CONTROL
EC-737
[VK45DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2007 April2007 M35/M45
AIR CONDITIONING CUT CONTROLPFP:23710
Input/Output Signal ChartNBS0059M
*1: This signal is sent to the ECM through CAN communication line.
*2: ECM determines the start signal status by the signals of engine speed and battery voltage.
System DescriptionNBS0059N
This system improves engine operation when the air conditioner is used.
Under the following conditions, the air conditioner is turned off.

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.
Sensor Input Signal to ECM ECM function Actuator
Air conditioner switch
Air conditioner ON signal*
1
Air conditioner
cut controlAir conditioner relay Accelerator pedal position sensor Accelerator pedal position
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE)Engine speed*
2
Engine coolant temperature sensor Engine coolant temperature
Battery
Battery voltage*
2
Refrigerant pressure sensor Refrigerant pressure
Power steering pressure sensor Power steering operation
Wheel sensor
Vehicle speed*
1

EC-738
[VK45DE]
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
Revision: 2007 April2007 M35/M45
AUTOMATIC SPEED CONTROL DEVICE (ASCD)PFP:18930
System DescriptionNBS0059O
INPUT/OUTPUT SIGNAL CHART
*: This signal is sent to the ECM through CAN communication line
BASIC ASCD SYSTEM
Refer to Owner's Manual for ASCD operating instructions.
Automatic Speed Control Device (ASCD) allows a driver to keep vehicle at predetermined constant speed
without depressing accelerator pedal. Driver can set vehicle speed in advance between approximately 40 km/
h (25 MPH) and 144 km/h (89 MPH).
ECM controls throttle angle of electric throttle control actuator to regulate engine speed.
Operation status of ASCD is indicated by CRUISE lamp and SET lamp in combination meter. If any malfunc-
tion occurs in ASCD system, it automatically deactivates control.
NOTE:
Always drive vehicle in safe manner according to traffic conditions and obey all traffic laws.
SET OPERATION
Press MAIN switch. (The CRUISE lamp in combination meter illuminates.)
When vehicle speed reaches a desired speed between approximately 40 km/h (25 MPH) and 144 km/h (89
MPH), press SET/COAST switch. (Then SET lamp in combination meter illuminates.)
ACCELERATE OPERATION
If the RESUME/ACCELERATE switch is pressed during cruise control driving, increase the vehicle speed until
the switch is released or vehicle speed reaches maximum speed controlled by the system.
And then ASCD will keep the new set speed.
CANCEL OPERATION
When any of following conditions exist, cruise operation will be canceled.

CANCEL switch is pressed

More than 2 switches at ASCD steering switch are pressed at the same time (Set speed will be cleared)

Brake pedal is depressed

Selector lever is changed to N, P, R position

Vehicle speed decreased to 13 km/h (8 MPH) lower than the set speed

TCS system is operated
When the ECM detects any of the following conditions, the ECM will cancel the cruise operation and inform
the driver by blinking indicator lamp.

Engine coolant temperature is slightly higher than the normal operating temperature, CRUISE lamp may
blink slowly.
When the engine coolant temperature decreases to the normal operating temperature, CRUISE lamp will
stop blinking and the cruise operation will be able to work by pressing SET/COAST switch or RESUME/
ACCELERATE switch.

Malfunction for some self-diagnoses regarding ASCD control: SET lamp will blink quickly.
If MAIN switch is turned to OFF during ASCD is activated, all of ASCD operations will be canceled and vehicle
speed memory will be erased.
Sensor Input signal to ECM ECM function Actuator
ASCD brake switch Brake pedal operation
ASCD vehicle speed controlElectric throttle control
actuator Stop lamp switch Brake pedal operation
ASCD steering switch ASCD steering switch operation
Park/Neutral position (PNP)
switchGear position
Wheel sensor Vehicle speed*
TCM Powertrain revolution*

TROUBLE DIAGNOSIS
EC-799
[VK45DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2007 April2007 M35/M45
2
P0031 P0032 P0051 P0052 Air fuel ratio (A/F) sensor 1 heater

P0037 P0038 P0057 P0058 Heated oxygen sensor 2 heater

P0075 P0081 Intake valve timing control solenoid valve

P0130 P0131 P0132 P0133 P0150 P0151 P0152 P0153 P2A00 P2A03 Air fuel ratio (A/F) sensor 1

P0137 P0138 P0139 P0157 P0158 P0159 Heated oxygen sensor 2

P0441 EVAP control system purge flow monitoring

P0443 P0444 P0445 EVAP canister purge volume control solenoid valve

P0447 P0448 EVAP canister vent control valve

P0451 P0452 P0453 EVAP control system pressure sensor

P0550 Power steering pressure sensor

P0603 ECM power supply

P0710 P0717 P0720 P0740 P0744 P0745 P1730 P1752 P1754 P1757 P1759 P1762 P1764 P1767 P1769 P1772
P1774 A/T related sensors, solenoid valves and switches

P1140 P1145 Intake valve timing control position sensor

P1217 Engine over temperature (OVERHEAT)

P1220 Fuel pump control module

P1805 Brake switch

P2100 P2103 Throttle control motor relay

P2101 Electric throttle control function

P2118 Throttle control motor
3

P0011 P0021 Intake valve timing control

P0171 P0172 P0174 P0175 Fuel injection system function

P0300 - P0308 Misfire

P0420 P0430 Three way catalyst function

P0442 P0456 EVAP control system (SMALL LEAK, VERY SMALL LEAK)

P0455 EVAP control system (GROSS LEAK)

P0506 P0507 Idle speed control system

P1148 P1168 Closed loop control

P1211 TCS control unit

P1212 TCS communication line

P1564 ICC steering switch / ASCD steering switch

P1568 ICC command value

P1572 ICC brake switch / ASCD brake switch

P1574 ICC vehicle speed sensor / ASCD vehicle speed sensor

P1715 Turbine revolution sensor

P1800 VIAS control solenoid valve

P2119 Electric throttle control actuator Priority Detected items (DTC)

TROUBLE DIAGNOSIS
EC-801
[VK45DE]
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: 2007 April2007 M35/M45
Symptom Matrix ChartNBS005AH
SYSTEM — BASIC ENGINE CONTROL SYSTEM
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
Fuel Fuel pump circuit 11232 22 3 2EC-1395
Fuel pressure regulator system334444444 4EC-791
Fuel injector circuit 11232 22 2EC-1389
Evaporative emission system334444444 4EC-741
Air Positive crankcase ventilation sys-
tem
334444444 41EC-753
Incorrect idle speed adjustment 1 1 1 1 1EC-780
Electric throttle control actuator 112332222 2 2EC-1322,
EC-1334
IgnitionIncorrect ignition timing adjustment33111 11 1EC-780
Ignition circuit 11222 22 2EC-1411
Main power supply and ground circuit22333 33 23EC-858
Mass air flow sensor circuit
1
122
222 2EC-906,
EC-915
Engine coolant temperature sensor circuit
333EC-926,
EC-939
Air fuel ratio (A/F) sensor 1 circuitEC-947
,
EC-957
,
EC-966
,
EC-975
,
EC-1365
Throttle position sensor circuit
22EC-932
,
EC-1054
,
EC-1233
,
EC-1235
,
EC-1350
Accelerator pedal position sensor circuit 3 2 1EC-1193
,
EC-1336
,
EC-1343
,
EC-1357
Knock sensor circuit 2 3EC-1070
Crankshaft position sensor (POS) circuit 2 2EC-1075
Camshaft position sensor (PHASE) circuit 3 2EC-1082
Vehicle speed signal circuit 2 3 3 3EC-1175
Power steering pressure sensor circuit 2 3 3EC-1181

EC-810
[VK45DE]
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
: Vehicle front
1. EVAP canister purge volume control
solenoid valve2. EVAP service port 3. EVAP canister vent control valve
4. EVAP control system pressure sensor 5. EVAP canister 6. Crankshaft position sensor (POS)
7. Power steering pressure sensor
PBIB2679E

EC-824
[VK45DE]
TROUBLE DIAGNOSIS
Revision: 2007 April2007 M35/M45
83 PSensor ground
(APP sensor 2)[Engine is running]
Warm-up condition

Idle speedApproximately 0V
85 V Data link connector[Ignition switch: ON]

CONSULT-II or GST: DisconnectedApproximately 5V - Battery volt-
age (11 - 14V)
86 P CAN communication line[Ignition switch: ON]Approximately 1.1 - 2.3V
Output voltage varies with the
communication status.
90 LSensor power supply
(APP sensor 1)[Ignition switch: ON]Approximately 5V
91 BRSensor power supply
(APP sensor 2)[Ignition switch: ON]Approximately 5V
94 L CAN communication line[Ignition switch: ON]Approximately 2.6 - 3.2V
Output voltage varies with the
communication status.
98 RAccelerator pedal position
sensor 2[Ignition switch: ON]

Engine: Stopped

Accelerator pedal: Fully released0.20 - 0.55V
[Ignition switch: ON]

Engine: Stopped

Accelerator pedal: Fully depressed1.85 - 2.40V
99 G/YICC steering switch
(models with ICC system)[Ignition switch: ON]

ICC steering switch: OFFApproximately 4.3V
[Ignition switch: ON]

MAIN switch: PressedApproximately 0V
[Ignition switch: ON]

CANCEL switch: PressedApproximately 1.3V
[Ignition switch: ON]

RESUME/ACCELERATE switch: PressedApproximately 3.7V
[Ignition switch: ON]

SET/COAST switch: PressedApproximately 3V
[Ignition switch: ON]

DISTANCE switch: PressedApproximately 2.2V
99 YASCD steering switch
(models with ASCD system)[Ignition switch: ON]

ASCD steering switch: OFFApproximately 4V
[Ignition switch: ON]

MAIN switch: PressedApproximately 0V
[Ignition switch: ON]

CANCEL switch: PressedApproximately 1V
[Ignition switch: ON]

RESUME/ACCELERATE switch: PressedApproximately 3V
[Ignition switch: ON]

SET/COAST switch: PressedApproximately 2V
101 V/R Stop lamp switch[Ignition switch: OFF]

Brake pedal: Fully releasedApproximately 0V
[Ignition switch: OFF]

Brake pedal: Slightly depressedBATTERY VOLTAGE
(11 - 14V) TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)