2008 INFINITI QX56 power steering

EC-338
< COMPONENT DIAGNOSIS >[VK56DE]
P1564 ASCD STEERING SWITCH
2. Disconnect combination switch harness connector M102.
3. Disconnect ECM harness connector.
4. Check harness continuity between combination switch terminal
15 and ECM terminal 67.
Refer to Wiring Diagram.
5. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M31, E152
• Harness connectors E5, F14
• Combination switch (spiral cable)
• Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
5.CHECK ASCD STEERING SWITCH INPUT SI GNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between ECM terminal 99 and combination switch terminal 14. Refer to Wiring Diagram.
2. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
• Harness connectors M31, E152
• Combination switch (spiral cable)
• Harness for open and short between ECM and combination switch
>> Repair open circuit or short to ground or short to power in harness or connectors.
7.CHECK ASCD STEERING SWITCH
Refer to EC-338, "
Component Inspection".
OK or NG
OK >> GO TO 8.
NG >> Replace ASCD steering switch.
8.CHECK INTERMITTENT INCIDENT
Refer to GI-35, "
How to Check Terminal" and GI-38, "Intermittent Incident".
>> INSPECTION END
Component InspectionINFOID:0000000001365462
ASCD STEERING SWITCH
1. Disconnect combination switch (spiral cable) harness connector M102. Continuity should exist.
BBIA0362E
Continuity should exist.
Revision: March 2010
2008 QX56

EC-430
< ECU DIAGNOSIS >[VK56DE]
ECM
5 L/B Throttle control motor (Open)[Ignition switch: ON]
• Engine: Stopped
• Selector lever: D
• Accelerator pedal: Fully depressed0 - 14V
6GR Heated oxygen sensor 2 heat-
er (bank 1) [Engine is running]
• Engine speed: Below 3,600 rpm after the
following conditions are met.
- Engine: After warming up
- Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load 0 - 1.0V
[Ignition switch: ON]
• Engine: Stopped
[Engine is running]
• Engine speed: Above 3,600 rpm BATTERY VOLTAGE
(11 - 14V)
10 W Intake valve timing control so-
lenoid valve (bank 1) [Engine is running]
•
Warm-up condition
• Idle speed BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
• Warm-up condition
• Engine speed: 2,000rpm 7 - 12V
11 L G Intake valve timing control so-
lenoid valve (bank 2) [Engine is running]
•
Warm-up condition
• Idle speed BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
• Warm-up condition
• Engine speed: 2,000rpm 7 - 12V
12 R Power steering pressure sen-
sor [Engine is running]
• Steering wheel: Being turned
0.5 - 4.5V
[Engine is running]
• Steering wheel: Not being turned 0.4 - 0.8V
TER-
MI-
NAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
PBIB1105E
PBIB1790E
PBIB1790E
Revision: March 2010 2008 QX56

EC-436
< ECU DIAGNOSIS >[VK56DE]
ECM
65
79
80
81G/R
V/W
W/R
W/G Ignition signal No. 8
Ignition signal No. 6
Ignition signal No. 4
Ignition signal No. 2 [Engine is running]
•
Warm-up condition
• Idle speed
NOTE:
The pulse cycle changes depending on rpm at
idle 0 - 0.3V
[Engine is running]
• Warm-up condition
• Engine speed: 2,500 rpm 0.1 - 0.6V
82 B/R Sensor ground
(APP sensor 1) [Engine is running]
•
Warm-up condition
• Idle speed Approximately 0V
83 G/W Sensor ground
(APP sensor 2) [Engine is running]
•
Warm-up condition
• Idle speed Approximately 0V
86 P CAN communication line — —
90 L Sensor power supply
(APP sensor 1) [Ignition switch: ON]
Approximately 5V
91 W/R Sensor power supply
(APP sensor 2) [Ignition switch: ON]
Approximately 5V
94 L CAN communication line — —
98 G/R Accelerator pedal position
sensor 2 [Ignition switch: ON]
• Engine: Stopped
• Accelerator pedal: Fully released
0.25 - 0.50V
[Ignition switch: ON]
• Engine: Stopped
• Accelerator pedal: Fully depressed 2.0 - 2.5V
99 G/R ASCD steering switch
(Models with ICC system) [Ignition switch: ON]
• ICC steering switch: OFF
Approximately 4.3V
[Ignition switch: ON]
• MAIN switch: Pressed Approximately 0V
[Ignition switch: ON]
• CANCEL switch: Pressed Approximately 1.3V
[Ignition switch: ON]
• RESUME/ACCELERATE switch: Pressed Approximately 3.7V
[Ignition switch: ON]
• SET/COAST switch: Pressed Approximately 3V
[Ignition switch: ON]
• DISTANCE switch: Pressed Approximately 2.2V
TER-
MI-
NAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)SEC986C
SEC987C
Revision: March 2010 2008 QX56

EC-462
< ECU DIAGNOSIS >[VK56DE]
ECM
DTC Index
INFOID:0000000001351328
EMISSION-RELATED DIAGNOSTIC INFORMATION ITEMS
× :Applicable —: Not applicable
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 P0731 P0732 P0733 P0734 P0735 P0740 P0744 P0745 P1730 P1752 P1757 P1762 P1767
P1772 P1774 A/T related sensors, solenoid valves and switches
• P1217 Engine over temperature (OVERHEAT)
• P1140 P1145 Intake valve timing control position sensor
• P1805 Brake switch
• P2100 P2103 P2118 Electric throttle control actuator
• P2101 Electric throttle control function
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 EVAP control system (SMALL LEAK)
• P0455 EVAP control system (GROSS LEAK)
• P0456 EVAP control sys tem (VERY SMALL LEAK)
• P0506 P0507 Idle speed control system
• P1148 P1168 Closed loop control
• P1211 TCS control unit
• P1212 TCS communication line
• P1421 Cold start control
• P1564 ICC/ASCD steering switch
• P1568 ICC command value
• P1572 ICC/ASCD brake switch
• P1574 ICC/ASCD vehicle speed sensor
• P2119 Electric throttle control actuator
Priority
Detected items (DTC)
Items
(CONSULT-IIl screen terms) DTC*
1
SRT code Trip
MILReference
page
CONSULT-IIl
GST*
2ECM*3
CAN COMM CIRCUIT U1000
1000*5—1 ×EC-87
CAN COMM CIRCUIT U1001
1001*5—1 or 2*9
2*10—
EC-87
CONTROL UNIT(CAN) U10101010—1×EC-88
NO DTC IS DETECTED.
FURTHER TESTING
MAY BE REQUIRED. P0000
0000——
Flashing*7EC-55
INT/V TIM CONT-B1 P00110011—2×EC-40
INT/V TIM CONT-B2 P00210021—2×EC-40
A/F SEN1 HTR (B1) P00310031—2×EC-97
A/F SEN1 HTR (B1) P00320032—2×EC-97
HO2S2 HTR (B1) P00370037—2×EC-100
HO2S2 HTR (B1) P00380038—2×EC-100
A/F SEN1 HTR (B2) P00510051—2×EC-97
Revision: March 2010 2008 QX56

EC-482
< SYMPTOM DIAGNOSIS >[VK56DE]
ENGINE CONTROL SYSTEM SYMPTOMS
1 - 6: The numbers refer to the order of inspection.
(continued on next page)
SYSTEM — ENGINE MECHANICAL & OTHER
Mass air flow sensor circuit
1
12 2
222 2 EC-106,
EC-113
Engine coolant temperature sensor circuit
333
EC-124,
EC-132
Air fuel ratio (A/F ) sensor 1 circuit EC-141
,
EC-145
,
EC-149
,
EC-153
,
EC-385
Throttle position sensor circuit
22EC-128
,
EC-194
,
EC-310
,
EC-312
,
EC-377
Accelerator pedal position sensor circuit 3 2 1EC-289
,
EC-370
,
EC-373
,
EC-381
Knock sensor circuit 23EC-204
Crankshaft position sensor (POS) circuit 2 2 EC-207
Camshaft position sensor (PHASE) circuit 3 2 EC-211
Vehicle speed signal circuit2 3 33EC-280
Power steering pressu re sensor circuit 23 3 EC-286
ECM 22333333333 EC-289,
EC-291
Intake valve timing control solenoid valve cir-
cuit 32 13223 3
EC-103
Park/Neutral position (PNP) signal circuit3 3 3 33EC-296
Refrigerant pressure sensor circuit 233 4 EC-423
Electrical load signal circuit 3EC-397
Air conditioner circuit 223333333 3 2 HAC-24
ABS actuator and electric unit (control unit) 4 BRC-37
SYMPTOM
Refer-
ence 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
Revision: March 2010 2008 QX56

EC-486
< PRECAUTION >[VK56DE]
PRECAUTIONS
PRECAUTION
PRECAUTIONS
Precaution for Supplemental Restraint Syst
em (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000006054103
The Supplemental Restraint System such as “A IR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inopera tive, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintent ional activation of the system. For re moval of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipmen t on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harn esses can be identified by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
• When working near the Airbag Diagnosis Sensor Unit or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or electri c power tools or strike near the sensor(s) with a
hammer. Heavy vibration could activate the sensor( s) and deploy the air bag(s), possibly causing
serious injury.
• When using air or electric power tools or hammers , always switch the Ignition OFF, disconnect the
battery, and wait at least 3 minu tes before performing any service.
Precaution Necessary for Steering W heel Rotation After Battery Disconnect
INFOID:0000000006211820
NOTE:
• This Procedure is applied only to models with Intelligent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
• Remove and install all control units after disconnecting both battery cables with the ignition knob in the
″LOCK ″ position.
• Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS, an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery pow er is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be rotated.
4. Perform the necessary repair operation.
Revision: March 2010 2008 QX56

PRECAUTIONSEC-487
< PRECAUTION > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
5. When the repair work is completed, return the ignition switch to the
″LOCK ″ position before connecting
the battery cables. (At this time, the steering lock mechanism will engage.)
6. Perform a self-diagnosis check of al l control units using CONSULT-III.
On Board Diagnosis (OBD) System of Engine and A/TINFOID:0000000001351222
The ECM has an on board diagnostic system . It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:
• Be sure to turn the ignition switch OFF and di sconnect the negative battery cable before any repair
or inspection work. The open/short circuit of re lated switches, sensors, solenoid valves, etc. will
cause the MIL to light up.
• Be sure to connect and lock the connectors secure ly after work. A loose (unlocked) connector will
cause the MIL to light up due to the open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)
• Certain systems and components, especially those related to OBD, may use a new style slide-lock-
ing type harness connector. For description and how to disconnect, refer to PG-65
.
• Be sure to route and secure the harnesses properly after work. The interference of the harness with
a bracket, etc. may cause the MIL to li ght up due to the short circuit.
• Be sure to connect rubber tubes properly afte r work. A misconnected or disconnected rubber tube
may cause the MIL to light up due to the malfuncti on of the EVAP system or fuel injection system,
etc.
• Be sure to erase the unnecessary malfunction information (repairs completed) from the ECM and TCM (Transmission control module) before returning the vehicle to the customer.
PrecautionINFOID:0000000006211821
•Always use a 12 volt battery as power source.
• Do not attempt to disconnect battery cables while engine is
running.
• Before connecting or disc onnecting the ECM harness con-
nector, turn ignition switch OFF and disconnect negative bat-
tery cable. Failure to do so may damage the ECM because
battery voltage is applied to ECM even if ignition switch is
turned OFF.
• Before removing parts, turn ig nition switch OFF and then dis-
connect negative battery cable.
• Do not disassemble ECM.
• If a battery cable is disconnected, the memory will return to
the ECM value.
The ECM will now start to sel f-control at its initial value.
Engine operation can vary slight ly when the terminal is dis-
connected. However, this is not an indication of a malfunc-
tion. Do not replace parts because of a slight variation.
• If the battery is disconnected, the following emission-related
diagnostic information will be lost within 24 hours.
- Diagnostic trouble codes
- 1st trip diagnostic trouble codes
- Freeze frame data
- 1st trip freeze frame data
- System readiness test (SRT) codes
- Test values
-
Presumed ethanol mixture ratio
SEF289H
PBIB1164E
Revision: March 2010 2008 QX56

PRECAUTIONSEM-3
< PRECAUTION >
C
DE
F
G H
I
J
K L
M A
EM
NP
O
PRECAUTION
PRECAUTIONS
Precaution for Supplemental
Restraint System (SRS) "AIR BAG" and "SEAT BELT
PRE-TENSIONER"
INFOID:0000000004857552
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severi ty of injury to the driver and front passenger for certain
types of collision. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and w hether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SR and SB section of this Service Man-
ual.
WARNING:
• To avoid rendering the SRS inoper ative, which could increase the risk of personal injury or death in
the event of a collision which would result in air bag inflation, all maintenance must be performed by
an authorized NISSAN/INFINITI dealer.
• Improper maintenance, including in correct removal and installation of the SRS, can lead to personal
injury caused by unintentional act ivation of the system. For removal of Spiral Cable and Air Bag
Module, see the SR section.
• Do not use electrical test equipm ent on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identi fied by yellow and/or orange harnesses or har-
ness connectors.
PRECAUTIONS WHEN USING POWER TOOLS (AIR OR ELECTRIC) AND HAMMERS
WARNING:
• When working near the Airbag Diagnosis Sensor Un it or other Airbag System sensors with the Igni-
tion ON or engine running, DO NOT use air or el ectric power tools or strike near the sensor(s) with a
hammer. Heavy vibration could activate the sensor( s) and deploy the air bag(s), possibly causing
serious injury.
• When using air or electric power tools or hammers, always switch the Ignition OFF, disconnect the battery, and wait at least 3 minutes before performing any service.
Precaution Necessary for Steering Wheel Rotation After Battery Disconnect
INFOID:0000000004857588
NOTE:
• This Procedure is applied only to models with Intelligent Key system and NATS (NISSAN ANTI-THEFT SYS-
TEM).
• Remove and install all control units after disconnecti ng both battery cables with the ignition knob in the
″ LOCK ″ position.
• Always use CONSULT-III to perform self-diagnosis as a part of each function inspection after finishing work.
If DTC is detected, perform trouble diagnosis according to self-diagnostic results.
For models equipped with the Intelligent Key system and NATS , an electrically controlled steering lock mech-
anism is adopted on the key cylinder.
For this reason, if the battery is disconnected or if the battery is discharged, the steering wheel will lock and
steering wheel rotation will become impossible.
If steering wheel rotation is required when battery power is interrupted, follow the procedure below before
starting the repair operation.
OPERATION PROCEDURE
1. Connect both battery cables. NOTE:
Supply power using jumper cables if battery is discharged.
2. Use the Intelligent Key or mechanical key to turn the ignition switch to the ″ACC ″ position. At this time, the
steering lock will be released.
3. Disconnect both battery cables. The steering lock will remain released and the steering wheel can be
rotated.
4. Perform the necessary repair operation.
Revision: March 2010 2008 QX56