2009 INFINITI QX56 brake light

EC-420
< ECU DIAGNOSIS >[VK56DE]
ECM
LOAD SIGNAL  Ignition switch: ONRear window defogger switch is ON
and/or lighting switch is in 2nd.
ON
Rear window defogger switch is OFF
and lighting switch is OFF. OFF
IGNITION SW  Ignition switch: ON → OFF → ON ON → OFF → ON
HEATER FAN SW  Engine: After warming up, idle the
engine Heater fan control switch: ON ON
Heater fan control switch: OFF OFF
BRAKE SW  Ignition switch: ON Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
INJ PULSE-B1
INJ PULSE-B2  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 2.0 - 2.8 msec
2,000 rpm 1.9 - 2.9 msec
IGN TIMING  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 10
° - 20 ° BTDC
2,000 rpm 25 ° - 45 ° BTDC
CAL/LD VALUE  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 14% - 33%
2,500 rpm 12% - 25%
MASS AIRFLOW  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 3.0 - 9.0 g·m/s
2,500 rpm 9.0 - 28.0 g·m/s
PURG VOL C/V  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle
(Accelerator pedal: Not depressed
even slightly, after engine starting.)
0%
2,000 rpm —
INT/V TIM (B1)
INT/V TIM (B2)  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle
−5 ° - 5 °CA
2,000 rpm Approx. 0 ° - 20 °CA
INT/V SOL (B1)
INT/V SOL (B2)  Engine: After warming up
 Selector lever: P or N
 Air conditioner switch: OFF
No load Idle 0% - 2%
2,000 rpm Approx. 25% - 50%
AIR COND RLY  Engine: After warming up, idle the
engine Air conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor: Operates)
ON
FUEL PUMP RLY
 For 1 second after turning ignition switch ON
 Engine running or cranking ON
 Except above conditions OFF
VENT CONT/V  Ignition switch: ON OFF
THRTL RELAY  Ignition switch: ON ON
COOLING FAN  Engine: After warming up, idle the
engine
 Air conditioner switch: OFF Engine coolant temperature: 99
°C
(210 °F) or less OFF
Engine coolant temperature: 100 °C
(212 °F) or more HI
HO2S2 HTR (B1)
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
MONITOR ITEM CONDITION SPECIFICATION
Revision: December 20092009 QX56

ECM
EC-421
< ECU DIAGNOSIS > [VK56DE]
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*1: Accelerator pedal position sensor 2 signal and throttle position sensor 2 signal are converted by ECM internally. Thus, the
y differ
from ECM terminals voltage signal.
*2: Before measuring the terminal voltage, confirm the battery is fully charged. Refer to PG-77
.
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-IIl value with the speedometer
indication. Almost the same speed as the
speedometer indication
TRVL AFTER MIL  Ignition switch: ON Vehicle has traveled after MIL has
turned ON.0 - 65,535 km
(0 - 40,7
23 mile)
A/F S1 HTR (B1)
A/F S1 HTR (B2)  Engine: After warming up, idle the engine 4 - 100%
AC PRESS SEN Engine: Idle
 Both A/C switch and blower fan switch: ON (Compressor operates.)
1.0 - 4.0V
VHCL SPEED SE  Turn drive wheels and compare CONSULT-IIl value with the speedometer
indication. Almost the same speed as the
speedometer indication
SET VHCL SPD  Engine: Running ASCD: Operating. The preset vehicle speed is dis-
played.
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
DIST SW  Ignition switch: ON DISTANCE switch: Pressed ON
DISTANCE switch: Released OFF
BRAKE SW1  Ignition switch: ON Brake pedal: Fully released ON
Brake pedal: Slightly depressed OFF
BRAKE SW2  Ignition switch: ON Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
CRUISE LAMP  Ignition switch: ON MAIN switch: Pressed at the 1st time
→
at the 2nd time ON
→ OFF
SET LAMP  MAIN switch: ON
 Vehicle speed: Between 40 km/h
(25 MPH) and 144 km/h (89
MPH) ASCD: Operating ON
ASCD: Not operating OFF
ALT DUTY  Engine: Idle 0 - 80%
BAT CUR SEN  Engine speed: Idle
 Battery: Fully charged*
2
 Selector lever: P or N
 Air conditioner switch: OFF
 No load Approx. 2,600 - 3,500mV
ALT DUTY SIG  Power generation voltage variable control: Operating ON
 Power generation voltage variable control: Not operating OFF
MONITOR ITEM CONDITION SPECIFICATION
Revision: December 20092009 QX56

EC-430
< ECU DIAGNOSIS >[VK56DE]
ECM
99 G/RASCD 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
101 R/W Stop lamp switch [Ignition switch: OFF]
 Brake pedal: Fully released
Approximately 0V
[Ignition switch: OFF]
 Brake pedal: Slightly depressed BATTERY VOLTAGE
(11 - 14V)
102 GR/R Transmission range signal [Ignition switch: ON]
 Selector lever: P or N
Approximately 0V
[Ignition switch: ON]
 Except the above gear position BATTERY VOLTAGE
(11 - 14V)
104 O Throttle cont rol motor relay[Ignition switch: OFF]
BATTERY VOLTAGE
(11 - 14V)
[Ignition switch: ON] 0 - 1.0V
106 BR/W Accelerator pedal position
sensor 1 [Ignition switch: ON]
 Engine: Stopped
 Accelerator pedal: Fully released
0.5 - 1.0V
[Ignition switch: ON]
 Engine: Stopped
 Accelerator pedal: Fully depressed 4.2 - 4.8V
107 V/R Fuel tank temperature sensor [Engine is running]Approximately 0 - 4.8V
Output voltage varies with fuel
tank temperature.
108 BR/W ICC brake switch
(Models with ICC system)
ASCD brake switch
(Models with ASCD system) [Ignition switch: ON]
 Brake pedal: Slightly depressed
Approximately 0V
[Ignition switch: ON]
 Brake pedal: Fully released BATTERY VOLTAGE
(11 - 14V)
109 L/W Ignition switch [Ignition switch: OFF]
0V
[Ignition switch: ON] BATTERY VOLTAGE
(11 - 14V)
111 W / B ECM relay
(Self shut-off) [Engine is running]
[Ignition switch: OFF]
 For a few seconds after turning ignition
switch OFF 0 - 1.5V
[Ignition switch: OFF]
 More than a few seconds after turning igni- tion switch OFF BATTERY VOLTAGE
(11 - 14V)
113 GR Fuel pump relay [Ignition switch: ON]
 For 1 second after turning ignition switch
ON
[Engine is running] 0 - 1.5V
[Ignition switch: ON]
 More than 1 second after turning ignition switch ON BATTERY VOLTAGE
(11 - 14V)
TER-
MI-
NAL NO.
WIRE
COLOR ITEM CONDITION DATA (DC Voltage)
Revision: December 20092009 QX56

EC-460
< ECU DIAGNOSIS >[VK56DE]
ECM
*1: 1st trip DTC No. is
the same as DTC No.
*2: This number is prescribed by SAE J2012.
*3: In Diagnostic Test Mode II (Self-diagnostic results), this number is controlled by NISSAN.
*4: SRT code will not be set if the self-diagnostic result is NG.
*5: The troubleshooting for this DTC needs CONSULT-III.
*6: When the fail-safe operations for both self-diagnoses occur, the MIL illuminates.
*7: When the ECM is in the mode of displaying SRT status, MIL may flash. For the details, refer to "How to Display SRT Status".
*8: 2WD models
*9: Models with ICC
*10: Models without ICC
Emission-related Diagnostic InformationINFOID:0000000004114214
DTC AND 1ST TRIP DTC
The 1st trip DTC (whose number is the same as the DT C number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previous ly, and the 1st trip DTC did not reoccur, the 1st trip
DTC will not be displayed.
If a malfunction is detected during the 1st trip, the 1st trip DTC is stored in the ECM memory. The MIL will not
light up (two trip detection logic). If the same malfunc tion is not detected in the 2nd trip (meeting the required
driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same malfunction is detected in the
2nd trip, both the 1st trip DTC and DTC are stored in t he ECM memory and the MIL lights up. In other words,
the DTC is stored in the ECM memory and the MIL light s up when the same malfunction occurs in two consec-
utive trips. If a 1st trip DTC is stored and a non-diagnostic operation is performed between the 1st and 2nd
trips, only the 1st trip DTC will continue to be stored. Fo r malfunctions that blink or light up the MIL during the
1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
DIFFERENCE OF KEY P1615 1615 — 2 — SEC-30
INTERLOCK P1730 1730 — 1×TM-76
INPUT CLUTCH SOL P1752 1752 — 1 ×TM-80
FR BRAKE SOLENOID P1757 1757 — 1 ×TM-82
DRCT CLUTCH SOL P1762 1762 — 1 ×TM-84
HLR CLUTCH SOLENOID P1767 1767 — 1 ×TM-86
L C BRAKE SOLENOID P1772 1772 — 1 ×TM-88
L C BRAKE SOLENOID P1774 1774 — 1 ×TM-90
BRAKE SW/CIRCUIT P1805 1805 — 2 — EC-348
ETC MOT PWR-B1 P2100 2100 — 1×EC-351
ETC FUNCTION/CIRC-B1 P2101 2101 — 1 ×EC-354
ETC MOT PWR P2103 2103 — 1 ×EC-351
ETC MOT-B1 P2118 2118 — 1 ×EC-358
ETC ACTR-B1 P2119 2119 — 1 ×EC-360
APP SEN 1/CIRC P2122 2122 — 1 ×EC-362
APP SEN 1/CIRC P2123 2123 — 1 ×EC-362
APP SEN 2/CIRC P2127 2127 — 1 ×EC-365
APP SEN 2/CIRC P2128 2128 — 1 ×EC-365
TP SENSOR-B1 P2135 2135 — 1 ×EC-369
APP SENSOR P2138 2138 — 1 ×EC-373
A/F SENSOR1 (B1) P2A00 2A00 — 2 ×EC-377
A/F SENSOR1 (B2) P2A03 2A03 — 2 ×EC-377
Items
(CONSULT-IIl screen terms) DTC*
1
SRT code Trip MIL
Reference
page
CONSULT-IIl
GST*
2ECM*3
Revision: December 20092009 QX56

DAYTIME LIGHT SYSTEMEXL-9
< FUNCTION DIAGNOSIS >
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DAYTIME LIGHT SYSTEM
System DiagramINFOID:0000000003776148
System DescriptionINFOID:0000000003776149
The headlamp system for Canada vehicles is equipped with a daytime light control unit that activates the high
beam headlamps at approximately half illumination whenever the engine is operating. If the parking brake is
applied before the engine is started the daytime lights will not be illuminated. The daytime lights will illuminate
once the parking brake is released. Thereafter, the daytime lights will continue to operate when the parking
brake is applied.
Component Parts LocationINFOID:0000000003776150
AWLIA1596GB
AWLIA1626ZZ
Revision: December 20092009 QX56

EXL-10
< FUNCTION DIAGNOSIS >
DAYTIME LIGHT SYSTEM
Component Description
INFOID:0000000003776151
After starting the engine with the parking brake released and the lighting switch in the OFF or 1ST position, the
headlamp high beam automatically turns on at a reduced intensity. With the lighting switch in the 2nd position
or with autolamps ON, the headlamps function the same as conventional light systems.
OPERATION
The BCM monitors inputs from the parking brake switch and the combination switch to determine when to acti-
vate the daytime light system. The BCM sends a dayti me light request to the IPDM E/R via the CAN commu-
nication lines. The IPDM E/R grounds the daytime light relay which in turn, provides power to the ground side
of the LH high beam lamp. Power flows backward through the LH high beam lamp to the IPDM E/R, through
the high beam fuses, through the RH high beam lamp circuit to the RH high beam lamp and on to ground. The
high beam lamps are wired in series which causes them to illuminate at a reduced intensity.
1. IPDM E/R E119, E122, E123, E124 2. BCM M18, M20 (view with instrument
panel removed)3. Daytime running light relay E103
4. Combination switch M28 5. Combination meter M23, M24 6. Parking brake switch M11
Revision: December 20092009 QX56

TRAILER TOWEXL-19
< FUNCTION DIAGNOSIS >
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TRAILER TOW
System DiagramINFOID:0000000005867517
System DescriptionINFOID:0000000005867518
TRAILER TAIL LAMP OPERATION
The trailer tail lamps are controlled by the trailer tow re lay 1 located behind the left side of the instrument panel
(IP). With the combination switch in the 1st position, the BCM detects the LI GHTING SWITCH 1ST POSITION
ON. The BCM sends a parking light ON request via the CAN communication lines to the IPDM E/R. The IPDM
E/R then activates the tail lamp relay which activates t he trailer tow relay 1 and sends power to the trailer con-
nector.
TRAILER TURN SIGNAL LAMP OPERATION
The trailer turn signal lamps are controlled by the BCM. When the turn signal switch is in the LH or RH position
with the ignition switch ON, the combination switch sends a signal to the BCM. The BCM detects the TURN
RH or TURN LH ON request. The BCM sends a control signal to the respective trailer turn relay which sends
power to the trailer connector.
TRAILER HAZARD LAMP OPERATION
The trailer hazard lamps are controlled by the BCM. When the hazard switch is pressed, the BCM detects the
the hazard ON request. The BCM then sends a control signal to both trailer turn relays which sends power to
the trailer connector.
TRAILER BRAKE LAMP OPERATION
The trailer brake lamps are controlled by the BCM. W hen the brake pedal is depressed, the combination meter
receives a stop lamp switch signal from the stop lamp switch. The combination meter then sends the brake
signal to the BCM via the CAN communication lines. The BCM then sends a control signal to both trailer turn
relays which sends power to the trailer connector.
AWLIA1764GB
Revision: December 20092009 QX56

EXL-20
< FUNCTION DIAGNOSIS >
TRAILER TOW
Component Parts Location
INFOID:0000000005867519
Component DescriptionINFOID:0000000005867520
1. BCM M18, M19, M20 (view with instru- ment panel removed) 2. IPDM E/R E119, E122, E123, E124 3. Combination meter M24, M25
4. Combination switch (lighting and turn signal switch) M28 5. Trailer tow relay 1 M51 (view with
steering member removed) 6. Battery
7. Trailer turn relay LH E156 8. Trailer turn relay RH E157 9. Trailer tow relay 2 E140
10. Stop lamp switch E38 (column shift), E42 (floor shift)
AWLIA1772ZZ
Part name Description
BCM • Receives lighting and turn signal requests from combination
switch.
• Receives stop lamp signal requests from combination meter via CAN communication.
• Sends lighting signal request to the IPDM E/R to control the tail lamp relay via CAN communication.
• Sends turn/hazard/brake control signal to the trailer turn relays.
IPDM E/R Activates the tail lamp relay upon request from the BCM via CAN
communication.
Revision: December 20092009 QX56