2011 INFINITI QX56 brake light

ECM
EC-73
< ECU DIAGNOSIS INFORMATION > [VK56VD]
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TP SEN 1-B1
 Ignition switch: ON
(Engine stopped)
 Selector lever: D position Accelerator pedal: Fully released More than 0.36 V
Accelerator pedal: Fully depressed Less than 4.75 V
TP SEN 2-B1*
1 Ignition switch: ON (Engine stopped)
 Selector lever: D position Accelerator pedal: Fully released More than 0.36 V
Accelerator pedal: Fully depressed Less than 4.75 V
FUEL T/TMP SE  Ignition switch: ON Indicates fuel tank tempera-
ture
EVAP SYS PRES  Ignition switch: ON Approx. 1.8 - 4.8 V
FUEL LEVEL SE  Ignition switch: ON Depending on fuel level of
fuel tank
START SIGNAL  Ignition switch: ON → START → ON OFF → ON → OFF
CLSD THL POS  Ignition switch: ON
(Engine stopped) Accelerator pedal: Fully released ON
Accelerator pedal: Slightly depressed OFF
AIR COND SIG  Engine: After warming up, idle
the engine Air conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)
ON
PW/ST SIGNAL  Engine: After warming up, idle
the engine Steering wheel: Not being turned OFF
Steering wheel: Being turned ON
LOAD SIGNAL  Ignition switch: ON Rear window defogger switch: ON
and/or
Lighting switch: 2nd position
ON
Rear window defogger switch and lighting
switch: OFF OFF
IGNITION SW  Ignition switch: ON → OFF → ON ON → OFF → ON
HEATER FAN SW  Engine: After warming up, idle
the engine Heater fan switch: ON ON
Heater fan switch: OFF OFF
BRAKE SW  Ignition switch: ON Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
IGN TIMING  Engine: After warming up
 Selector lever: P or N position
 A/C switch: OFF
No load Idle 1 - 4
°BTDC
2,000 rpm 25 - 45 °BTDC
COMBUSTION — These items are displayed
but are not applicable to this
model.
CAL/LD VALUE  Engine: After warming up
 Selector lever: P or N position
 A/C switch: OFF
No load Idle 5 - 35%
2,500 rpm 5 - 35%
MASS AIRFLOW  Engine: After warming up
 Selector lever: P or N position
 A/C switch: OFF
No load Idle 2.0 - 6.0 g/s
2,500 rpm 7.0 - 20.0 g/s
PURG VOL C/V  Engine: After warming up
 Selector lever: P or N position
 A/C switch: OFF
No load Idle
(Accelerator pedal: Not depressed even
slightly, after engine starting.)
0%
2,000 rpm 5%
INT/V SOL (B1)  Engine: After warming up
 Selector lever: P or N position
 A/C switch: OFF
No load Idle 0 - 2%
2,000 rpm Approx. 0 - 50%
Monitor Item Condition Values/Status
Revision: 2010 May2011 QX56

EC-74
< ECU DIAGNOSIS INFORMATION >[VK56VD]
ECM
INT/V SOL (B2) Engine: After warming up
 Selector lever: P or N position
 A/C switch: OFF
No load Idle 0 - 2%
2,000 rpm Approx. 0 - 50%
AIR COND RLY  Engine: After warming up, idle
the engine A/C switch: OFF OFF
A/C switch: ON
(Compressor operates)
ON
VENT CONT/V  Ignition switch: ON OFF
THRTL RELAY  Ignition switch: ON ON
A/F S1 HTR (B1)  Engine: After warming up, idle the engine
(More than 140 seconds after starting engine) 4 - 100%
A/F S1 HTR (B2)  Engine: After warming up, idle the engine
(More than 140 seconds after starting engine) 4 - 100%
HO2S2 HTR (B1)  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 ON
 Engine speed: Above 3,600 rpm OFF
HO2S2 HTR (B2)  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 ON
 Engine speed: Above 3,600 rpm OFF
ALT DUTY SIG  Power generation voltage variable control: Operating ON
 Power generation voltage variable control: Not operating OFF
I/P PULLY SPD  Vehicle speed: More than 20 km/h (12 MPH) Almost the same speed as
the tachometer indication
VEHICLE SPEED  Turn drive wheels and compare CONSULT-III value with the speedometer in-
dication. Almost the same speed as
the speedometer indication
IDL A/V LEARN  Engine: Running Idle air volume learning has not been per-
formed yet.
YET
Idle air volume learning has already been
performed successfully. CMPLT
TRVL AFTER MIL  Ignition switch: ON Vehicle has traveled after MIL has illumi-
nated.0 - 65,535 km
(0 - 40,7
23 miles)
SNOW MODE SW  Ignition switch: ON Snow mode switch: ON ON
Snow mode switch: OFF OFF
ENG OIL TEMP  Engine: After warming up More than 70 °C (158 °F)
MAIN SW  Ignition switch: ON MAIN switch: Pressed ON
MAIN switch: Released OFF
CANCEL SW  Ignition switch: ON CANCEL switch: Pressed ON
CANCEL switch: Released OFF
RESUME/ACC SW  Ignition switch: ON RESUME/ACCELERATE switch:
Pressed
ON
RESUME/ACCELERATE switch: Re-
leased OFF
SET SW  Ignition switch: ON SET/COAST switch: Pressed ON
SET/COAST switch: Released OFF
BRAKE SW1
(ASCD/ICC brake
switch)  Ignition switch: ON
Brake pedal: Fully released ON
Brake pedal: Slightly depressed OFF
Monitor Item Condition Values/Status
Revision: 2010 May2011 QX56

ECM
EC-75
< ECU DIAGNOSIS INFORMATION > [VK56VD]
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BRAKE SW2
(Stop lamp switch)
 Ignition switch: ON Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
DIST SW  Ignition switch: ON DISTANCE switch: Pressed ON
DISTANCE switch: Released OFF
CRUISE LAMP  Ignition switch: ON MAIN switch: Pressed at the 1st time
→
at the 2nd time ON
→ OFF
AC EVA TEMP  Engine: Running Indicates A/C evaporator
temperature sent from“uni-
fied meter and A/C amp.”.
AC EVA TARGET  Engine: Running Indicates target A/C evapo-
rator temperature sentfrom
“unified meter and A/C
amp.”.
FAN DUTY  Engine: Running 0 - 100%
ALT DUTY  Engine: Idle 0 - 80%
BAT CUR SEN  Engine speed: Idle
 Battery: Fully charged*
2
 Selector lever: P or N position
 A/C switch: OFF
No load Approx. 2,600 - 3,500 mV
A/F ADJ-B1  Engine: Running −0.330 - 0.330
A/F ADJ-B2  Engine: Running −0.330 - 0.330
P/N POSI SW  Ignition switch: ON Selector lever: P or N ON
Selector lever: Except above position OFF
INT/A TEMP SE  Ignition switch: ON Indicates intake air temper-
ature
AC PRESS SEN  Engine: Idle
 Both A/C switch and blower fan switch: ON (Compressor operates) 1.0 - 4.0 V
FUEL PRES SEN  Engine: After warming up
 Selector lever: P or N position
 A/C switch: OFF
No load Idle Approx. 2.74 Mpa
2,000 rpm Approx. 3.0 Mpa
FUEL INJ B1  Engine: After warming up
 Selector lever: P or N position
 A/C switch: OFF
No load Idle Approx. 1.4 msec
2,000 rpm Approx. 1.0 msec
FUEL INJ B2  Engine: After warming up
 Selector lever: P or N position
 A/C switch: OFF
No load Idle Approx. 1.4 msec
2,000 rpm Approx. 1.0 msec
INT/V TIM (B1)  Engine: After warming up
 Selector lever: P or N position
 A/C switch: OFF
No load Idle
−5 - 5 °CA
2,000 rpm Approx. 0 - 30 °CA
INT/V TIM (B2)  Engine: After warming up
 Selector lever: P or N position
 A/C switch: OFF
No load Idle
−5 - 5 °CA
2,000 rpm Approx. 0 - 30 °CA
MAP SENSOR  Engine: After warming up
 Selector lever: P or N position
 A/C switch: OFF
No load Idle Approx. 1.0 V
2,000 rpm Approx. 1.35 V
EVAP LEAK DIAG  Ignition switch: ON Indicates the condition of
EVAP leak diagnosis.
Monitor Item Condition Values/Status
Revision: 2010 May2011 QX56

EC-92
< ECU DIAGNOSIS INFORMATION >[VK56VD]
ECM
142
(R/W) 175
(B) Fuel pump control module
(FPCM) check
Input[When cranking engine] 0 V
[Engine is running]
 Warm-up condition
 Idle speed
9 V
143
(L/Y) 150
(R) EVAP control system pressure
sensor
Input [Ignition switch: ON] 1.8 - 4.8 V
144
(O/B) 150
(R) Refrigerant pressure sensor Input [Engine is running]
 Warm-up condition
 Both A/C switch and blower fan mo-
tor switch: ON (Compressor oper-
ates) 1.0 - 4.0 V
146 (L) — CAN communication line — — —
147
(G/Y) 175
(B) ASCD/ICC brake switch Input [Ignition switch: ON]
 Brake pedal: Slightly depressed
0 V
[Ignition switch: ON]
 Brake pedal: Fully released BATTERY VOLTAGE
(11 - 14 V)
150 (R) —Sensor ground
(Refrigerant pressure sensor/
Battery current sensor/EVAP
control system pressure sensor) —— —
151 (P) — CAN communication line — — —
156 (L) 175
(B) Power supply
for ECM (Back-
up) Input [Ignition switch: OFF] BATTERY VOLTAGE
(11 - 14 V)
158
(W/B) 175
(B) Stop lamp switch Input [Ignition switch: OFF]
 Brake pedal: Fully released
0 V
[Ignition switch: OFF]
 Brake pedal: Slightly depressed BATTERY VOLTAGE
(11 - 14 V)
161 (R/W) — ENG communication line — — —
163
(L/G) 175
(B) ECM relay (Self shut-off) Output [Engine is running]
[Ignition switch: OFF]
 A few seconds after turning ignition
switch OFF 0 - 1.5 V
[Ignition switch: OFF]
 More than a few seconds after turn- ing ignition switch OFF BATTERY VOLTAGE
(11 - 14 V)
165
(GR/ R) —
NOTE:
Not used —— —
166 (W) — ENG communication line — — —
Te r m i n a l N o .
(Wire color) Description
ConditionVa l u e
(Approx.)
+ – Signal name Input/
Output
Revision: 2010 May2011 QX56

EC-148
< BASIC INSPECTION >[VK56VD]
IDLE AIR VOLUME LEARNING
IDLE AIR VOLUME LEARNING
DescriptionINFOID:0000000006217750
Idle Air Volume Learning is a function of ECM to learn
the idle air volume that keeps engine idle speed within
the specific range. It must be perfo rmed under the following conditions:
 Each time the electric throttle control actuator or ECM is replaced.
 Idle speed or ignition timing is out of the specification.
Work ProcedureINFOID:0000000006217751
1.PRECONDITIONING
Check that all of the following conditions are satisfied.
Learning will be cancelled if any of the follo wing conditions are missed for even a moment.
 Battery voltage: More than 12.9 V (At idle)
 Engine coolant temperature: 70 - 105 °C (158 - 221 °F)
 Selector lever position: P or N
 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
started the headlamp will not illuminate.
 Steering wheel: Neutral (Straight-ahead position)
 Vehicle speed: Stopped
 Transmission: Warmed-up
- With CONSULT-III: Drive vehicle until “ATF TEMP 2” in “DATA MONITOR” mode of “A/T” system indicates
less than 0.9 V.
- Without CONSULT-III: Drive vehicle for 10 minutes.
Will CONSULT-III be used?
YES >> GO TO 2.
NO >> GO TO 3.
2.PERFORM IDLE AIR VOLUME LEARNING
WITH CONSULT-III
1. Perform Accelerator Pedal Released Position Learning. Refer to EC-146, "
Work Procedure".
2. Perform Throttle Valve Closed Position Learning. EC-147, "
Work Procedure".
3. Start engine and warm it up to normal operating temperature.
4. Select “IDLE AIR VOL LEARN” in “WORK SUPPORT” mode.
5. Touch “START” and wait 20 seconds.
Is
“CMPLT” displayed on CONSULT-III screen?
YES >> GO TO 4.
NO >> GO TO 5.
3.PERFORM IDLE AIR VOLUME LEARNING
WITHOUT CONSULT-III
NOTE:
 It is better to count the ti me accurately with a clock.
 It is impossible to switch the di agnostic mode when an accelerator pedal position sensor circuit has
a malfunction.
1. Perform Accelerator Pedal Released Position Learning. Refer to EC-146, "
Work Procedure".
2. Perform Throttle Valve Closed Position Learning. EC-147, "
Work Procedure".
3. Start engine and warm it up to normal operating temperature.
4. Turn ignition switch OFF and wait at least 10 seconds.
5. Confirm that accelerator pedal is fully releas ed, turn ignition switch ON and wait 3 seconds.
6. Repeat the following procedure quickly 5 times within 5 seconds.
- Fully depress the accelerator pedal.
- Fully release the accelerator pedal.
7. Wait 7 seconds, fully depress the accelerator pedal for approx. 20 seconds until the MIL stops blinking
and turns ON.
8. Fully release the accelerator pedal within 3 seconds after the MIL turns ON.
Revision: 2010 May2011 QX56

P1572 ASCD BRAKE SWITCHEC-439
< DTC/CIRCUIT DIAGNOSIS > [VK56VD]
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Always drive vehicle at a safe speed.
NOTE:
This procedure may be conducted with the drive wheel
s lifted in the shop or by driving the vehicle.
If a road test is expected to be easier , it is unnecessary to lift the vehicle.
2. Check 1st trip DTC.
Is 1st trip DTC detected?
YES >> Go to EC-439, "Diagnosis Procedure".
NO >> INSPECTION END
Diagnosis ProcedureINFOID:0000000006217944
1.CHECK OVERALL FUNCTION-I
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DATA MONITOR” mode with CONSULT-III.
3. Check “BRAKE SW1” indication under the following conditions.
WITHOUT CONSULT-III
1. Turn ignition switch ON.
2. Check the voltage between ECM harness connector terminals as per the following.
Is the inspection result normal?
YES >> GO TO 2.
NO >> GO TO 3.
2.CHECK OVERALL FUNCTION-II
WITH CONSULT-III
Select “BRAKE SW2” and check indication under the following conditions.
WITHOUT CONSULT-III
Check the voltage between ECM harness connector terminals under the following conditions.
Vehicle speed More than 30 km/h (19 mph)
Selector lever Suitable position
Driving location Depress the brake pedal for more than 5 seconds so as
not to come off from the above-mentioned vehicle speed.
Monitor item Condition Indication
BRAKE SW1
(ASCD brake switch) Brake pedalSlightly depressed OFF
Fully released ON
ECM Condition Voltage (V)
Connector +–
Terminal Terminal
E80 147
(ASCD brake switch signal) 175 Brake pedalSlightly depressed Approx. 0
Fully released Battery voltage
Monitor item Condition Indication
BRAKE SW2
(Stop lamp switch) Brake pedalSlightly depressed ON
Fully released OFF
Revision: 2010 May2011 QX56

EC-440
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1572 ASCD BRAKE SWITCH
Is the inspection result normal?
YES >> GO TO 13.
NO >> GO TO 8.
3.CHECK ASCD BRAKE SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Turn ignition switch ON.
4. Check the voltage between ASCD brake switch harness connector and ground.
Is the inspection result normal?
YES >> GO TO 5.
NO >> GO TO 4.
4.DETECT MALFUNCTIONING PART
Check the following.
 10 A fuse (No. 3)
 Harness for open or short between ASCD brake switch and fuse
 Loose or poor connection for each connector and harness
>> Repair open circuit or short to ground in harness or connectors.
5.CHECK ASCD BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check the continuity between ASCD brake s witch 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 7.
NO >> GO TO 6.
6.DETECT MALFUNCTIONING PART
Check the following.
 Harness for open or short between ECM and ASCD brake switch
 Loose or poor connection for each connector and harness
>> Repair open circuit, short to ground or short to power in harness or connectors.
7.CHECK ASCD BRAKE SWITCH
Refer to EC-442, "
Component Inspection (ASCD Brake Switch)"
Is the inspection result normal?
ECM
Condition Voltage (V)
Connector +–
Terminal Terminal
E80 158
(Stop lamp switch signal) 175 Brake pedalSlightly depressed Battery voltage
Fully released Approx. 0
ASCD brake switch
Ground Voltage
Connector Terminal
E109 1 Ground Battery voltage
ASCD brake switch ECM Continuity
Connector Terminal Connector Terminal
E109 2 E80 147 Existed
Revision: 2010 May2011 QX56

EC-442
< DTC/CIRCUIT DIAGNOSIS >[VK56VD]
P1572 ASCD BRAKE SWITCH
Component Inspection (ASCD Brake Switch)
INFOID:0000000006217945
1.CHECK ASCD BRAKE SWITCH-I
1. Turn ignition switch OFF.
2. Disconnect ASCD brake switch harness connector.
3. Check the continuity between ASCD brake s witch terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 2.
2.CHECK ASCD BRAKE SWITCH-II
1. Adjust ASCD brake switch installation. Refer to BR-21, "
Inspection and Adjustment".
2. Check the continuity between ASCD brake s witch terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace ASCD brake switch. Refer to BR-20, "
Removal and Installation".
Component Inspection (Stop Lamp Switch)INFOID:0000000006217946
1.CHECK STOP LAMP SWITCH-I
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check the continuity between stop lamp switch terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> GO TO 2.
2.CHECK STOP LAMP SWITCH-II
1. Adjust stop lamp switch installation. Refer to BR-21, "
Inspection and Adjustment".
2. Check the continuity between stop lamp switch terminals under the following conditions.
Is the inspection result normal?
YES >> INSPECTION END
NO >> Replace stop lamp switch. Refer to BR-20, "
Removal and Installation".
Terminals Condition Continuity
1 and 2 Brake pedal Fully released Existed
Slightly depressed Not existed
Terminals Condition Continuity
1 and 2 Brake pedal Fully released Existed
Slightly depressed Not existed
Terminals Condition Continuity
1 and 2 Brake pedal Fully released Not existed
Slightly depressed Existed
Terminals Condition Continuity
1 and 2 Brake pedal Fully released Not existed
Slightly depressed Existed
Revision: 2010 May2011 QX56