EC-30Revision: November 2009
AUTOMATIC SPEED CONTROL DEVICE (ASCD)
2006 QX56
COAST OPERATION
When the SET/COAST switch is pressed during cruise control driving, decrease vehicle set speed until the
switch is released. And then ASCD will keep the new set speed.
RESUME OPERATION
When the RESUME/ACCELERATE switch is pressed after cancel operation other than pressing MAIN switch
is performed, vehicle speed will return to last set speed. To resume vehicle set speed, vehicle condition must
meet following conditions.
Brake pedal is released
A/T selector lever is in other than P and N positions
Vehicle speed is greater than 40 km/h (25 MPH) and less than 144 km/h (89 MPH)
Component DescriptionUBS00KZD
ASCD STEERING SWITCH
Refer to EC-494 .
ASCD BRAKE SWITCH
Refer to EC-511 , and EC-586 .
STOP LAMP SWITCH
Refer to EC-511 , EC-523 and EC-586 .
ELECTRIC THROTTLE CONTROL ACTUATOR
Refer to EC-528 , EC-534 , EC-540 and EC-545 .
ASCD INDICATOR
Refer to EC-593 .
BASIC SERVICE PROCEDUREEC-71
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Revision: November 2009 2006 QX56
BASIC SERVICE PROCEDUREPFP:00018
Basic InspectionUBS00KZU
1. INSPECTION START
1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for scheduled maintenance.
2. Open engine hood and check the following:
–Harness connectors for improper connections
–Wiring harness for improper connections, pinches and cut
–Vacuum hoses for splits, kinks and improper connections
–Hoses and ducts for leaks
–Air cleaner clogging
–Gasket
3. Confirm that electrical or mechanical loads are not applied.
–Headlamp switch is OFF.
–Air conditioner switch is OFF.
–Rear window defogger switch is OFF.
–Steering wheel is in the straight-ahead position, etc.
4. Start engine and warm it up until engine coolant temperature indicator points the middle of gauge.
Ensure engine stays below 1,000 rpm.
5. Run engine at about 2,000 rpm for about 2 minutes under no load.
6. Make sure that no DTC is displayed with CONSULT-II or GST.
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnostic Procedure.
>> GO TO 3.
SEF983U
SEF976U
SEF977U
EC-78Revision: November 2009
BASIC SERVICE PROCEDURE
2006 QX56
Accelerator Pedal Released Position LearningUBS00KZY
DESCRIPTION
Accelerator Pedal Released Position Learning is an operation to learn the fully released position of the accel-
erator pedal by monitoring the accelerator pedal position sensor output signal. It must be performed each time
harness connector of accelerator pedal position sensor or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON and wait at least 2 seconds.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Turn ignition switch ON and wait at least 2 seconds.
5. Turn ignition switch OFF and wait at least 10 seconds.
Throttle Valve Closed Position LearningUBS00KZZ
DESCRIPTION
Throttle Valve Closed Position Learning is an operation to learn the fully closed position of the throttle valve by
monitoring the throttle position sensor output signal. It must be performed each time harness connector of
electric throttle control actuator or ECM is disconnected.
OPERATION PROCEDURE
1. Make sure that accelerator pedal is fully released.
2. Turn ignition switch ON.
3. Turn ignition switch OFF wait at least 10 seconds.Make sure that throttle valve moves during above 10 seconds by confirming the operating sound.
Idle Air Volume LearningUBS00L00
DESCRIPTION
Idle Air Volume Learning is an operation to learn the idle air volume that keeps each engine within the specific
range. It must be performed under any of the following conditions:
Each time electric throttle control actuator or ECM is replaced.
Idle speed or ignition timing is out of specification.
PREPARATION
Before performing Idle Air Volume Learning, make sure that all of the following conditions are satisfied.
Learning will be cancelled if any of the following conditions are missed for even a moment.
Battery voltage: More than 12.9V (At idle)
Engine coolant temperature: 70 - 100 °C (158 - 212 °F)
Park/Neutral position (PNP) switch: ON
Electric load switch: OFF
(Air conditioner, headlamp, rear window defogger)
On vehicles equipped with daytime light systems, if the parking brake is applied before the engine
is start the headlamp will not be illuminated.
Steering wheel: Neutral (Straight-ahead position)
Vehicle speed: Stopped
Transmission: Warmed-up
–With CONSULT-II: Drive vehicle until “ATF TEMP SE 1 ” in “DATA MONITOR” mode of “A/T” system indi-
cates less than 0.9V.
–Without CONSULT-II: Drive vehicle for 10 minutes.
OPERATION PROCEDURE
With CONSULT-II
1. Perform EC-78, "Accelerator Pedal Released Position Learning" .
2. Perform EC-78, "
Throttle Valve Closed Position Learning" .
3. Start engine and warm it up to normal operating temperature.
4. Check that all items listed under the topic PREPARATION (previously mentioned) are in good order.
EC-90Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
2P0031 P0032 P0051 P0052 Air fuel ratio (A/F) sensor 1 heater
P0037 P0038 P0057 P0058 Heated oxygen sensor 2 heater
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
P0700 P0710 P0717 P0720 P0740 P0744 P0745 P1730 P1752 P1754 P1757 P1759 P1762 P1764 P1767 P1769
P1772 P1774 A/T related sensors and solenoid valves
P1217 Engine over temperature (OVERHEAT)
P1805 Brake switch
P2100 P2103 P2118 Electric throttle control actuator
P2101 Electric throttle control function
3
P0171 P0172 P0174 P0175 Fuel injection system function
P0300 - P0308 Misfire
P0420 P0430 Three way catalyst function
P0442 P0455 P0456 EVAP control system
P0506 P0507 Idle speed control system
P1148 P1168 Closed loop control
P1211 TCS control unit
P1212 TCS communication line
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)
TROUBLE DIAGNOSISEC-93
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Revision: November 2009 2006 QX56
1 - 6: The numbers refer to the order of inspection.
(continued on next page)Vehicle speed signal circuit
2 3 33EC-442
Power steering pressure sensor circuit 23 3 EC-448
ECM 22333333333 EC-453,
EC-457
Park/Neutral position (PNP) switch circuit 3 3 3 33EC-465
Refrigerant pressure sensor circuit 233 4 EC-630
Electrical load signal circuit 3EC-596
Air conditioner circuit 223333333 3 2 AT C - 3 4
ABS actuator and electric unit (control unit)4EC-471
,
EC-472
or BRC-11
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
EC-106Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
3LThrottle control motor relay
power supply [Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
4 L/W Throttle control motor (Close) [Ignition switch: ON]
Engine: Stopped
Selector lever: D
Accelerator pedal: Fully released0 - 14V
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
heater (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)
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
13 O Crankshaft position sensor
(POS) [Engine is running]
Warm-up condition
Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle Approximately 10V
[Engine is running]
Engine speed: 2,000 rpm Approximately 10V
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
PBIB1104E
PBIB1105E
PBIB1041E
PBIB1042E
TROUBLE DIAGNOSISEC-111
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Revision: November 2009 2006 QX5682 B/RSensor 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
85 G/W 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 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 [Ignition switch: ON]Approximately 2.6 - 3.2V
Output voltage varies with the
communication status.
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/Y 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
99 G/Y ASCD steering switch
(Models with ASCD system) [Ignition switch: ON]
ASCD steering switch: OFF
Approximately 4V
[Ignition switch: ON]
MAIN switch: Pressed Approximately 0V
[Ignition switch: ON]
CANCEL switch: Pressed Approximately 1V
[Ignition switch: ON]
RESUME/ACCELERATE switch: Pressed Approximately 3V
[Ignition switch: ON]
SET/COAST switch: Pressed Approximately 2V
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
TROUBLE DIAGNOSISEC-115
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Revision: November 2009 2006 QX56
ENGINE CONTROL COMPONENT PARTS/CONTROL SYSTEMS APPLICATION
ItemDIAGNOSTIC TEST MODE
WORK SUP-
PORT SELF-DIAGNOSTIC
RESULTS DATA
MONI- TOR DATA
MONI- TOR
(SPEC) ACTIVE
TEST DTC & SRT
CONFIRMATION
DTC*1 FREEZE
FRAME
DATA*2 SRT
STATUS DTC
WORK
SUP-
PORT
ENGINE CONTROL COMPONENT PARTS
INPUT
Crankshaft position sensor (POS) ××××
Camshaft position sensor (PHASE) ××××
Mass air flow sensor ×××
Engine coolant temperature sensor ×××××
Air fuel ratio (A/F) sensor 1 ×××× ×
Heated oxygen sensor 2 ×××× ×
Wheel sensor ××××
Accelerator pedal position sensor ×××
Throttle position sensor ××××
Fuel tank temperature sensor ××××
EVAP control system pressure
sensor ××
×
Intake air temperature sensor ××××
Knock sensor ×
Refrigerant pressure sensor ××
Closed throttle position switch
(accelerator pedal position sensor
signal) ××
Air conditioner switch ××
Park/neutral position (PNP) switch ×××
Stop lamp switch ×××
Power steering pressure sensor ×××
Battery voltage ××
Load signal ××
Fuel level sensor ×××
ICC steering switch ×××
ASCD steering switch ×××
ICC brake switch ×××
ASCD brake switch ×××