Page 1801 of 3383

EC-590Revision: November 2009
ASCD BRAKE SWITCH
2006 QX56
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 voltage between ASCD brake switch terminal 1 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
Harness connectors M31, E152
Fuse block (J/B) connector M4
10A fuse
Harness for open or short between ASCD brake switch and fuse
>> Repair open circuit or short to ground or short to power 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 harness continuity between ECM terminal 108 and ASCD brake switch terminal 2. Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
6. CHECK ASCD BRAKE SWITCH
Refer to EC-592, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> Replace ASCD brake switch.
BBIA0373E
Voltage: Battery voltage
PBIB0857E
Continuity should exist.
Page 1802 of 3383

ASCD BRAKE SWITCHEC-591
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EC
Revision: November 2009 2006 QX56
7. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check voltage between stop lamp switch terminal 3 and ground with CONSULT -II or tester.
OK or NG
OK >> GO TO 9.
NG >> GO TO 8.
8. DETECT MALFUNCTIONING PART
Check the following.
Harness connectors M31, E152
Fuse block (J/B) connector M60
10A fuse
Harness for open or short between stop lamp switch and battery
>> Repair open circuit or short to ground or short to power in harness or connectors.
9. CHECK STOP LAMP SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ECM terminal 101 and stop lamp switch terminal 4. Refer to Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 10.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
10. CHECK STOP LAMP SWITCH
Refer to EC-592, "
Component Inspection" .
OK or NG
OK >> GO TO 11.
NG >> Replace stop lamp switch.
BBIA0373E
Voltage: Battery voltage
PBIB2102E
Continuity should exist.
Page 1807 of 3383

EC-596Revision: November 2009
ELECTRICAL LOAD SIGNAL
2006 QX56
ELECTRICAL LOAD SIGNALPFP:25350
DescriptionUBS00HDL
The electrical load signal (Headlamp switch signal, rear window defogger switch signal, etc.) is transferred
through the CAN communication line from BCM to ECM via IPDM E/R.
CONSULT-II Reference Value in Data Monitor ModeUBS00HDM
Specification data are reference values.
Diagnostic ProcedureUBS00HDN
1. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-I
1. Turn ignition switch ON.
2. Connect CONSULT-II and select “DATA MONITOR ” mode.
3. Select “LOAD SIGNAL ” and check indication under the following
conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 4.
2. CHECK LOAD SIGNAL CIRCUIT OVERALL FUNCTION-II
Check “LOAD SIGNAL ” indication under the following conditions.
OK or NG
OK >> GO TO 3.
NG >> GO TO 5.
MONITOR ITEM CONDITION SPECIFICATION
LOAD SIGNAL
Ignition switch: ON Rear 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
HEATER FAN SW
Engine: After warming up, idle
the engine Heater fan control switch: ON
ON
Heater fan control switch: OFF OFF
Condition Indication
Rear window defogger switch: ON ON
Rear window defogger switch: OFF OFF
PBIB0103E
ConditionIndication
Lighting switch: ON at 2nd position ON
Lighting switch: OFF OFF
PBIB0103E
Page 1811 of 3383

EC-600Revision: November 2009
FUEL INJECTOR
2006 QX56
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
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.
: Average voltage for pulse signal (Actual pulse signal can be confirmed by oscilloscope.)
Diagnostic ProcedureUBS00L1I
1. INSPECTION START
Turn ignition switch to START.
Is any cylinder ignited?
Ye s o r N o
Yes >> GO TO 2.
No >> GO TO 3.
TER-
MINAL NO. WIRE
COLOR ITEM
CONDITION DATA (DC Voltage)
21
22
23
40
41
42
44
63 O/L
BR
GR/W
Y/G
P
L
O
G Fuel injector No. 5
Fuel injector No. 3
Fuel injector No. 1
Fuel injector No. 6
Fuel injector No. 4
Fuel injector No. 2
Fuel injector No. 7
Fuel injector No. 8 [Engine is running]
Warm-up condition
Idle speed
NOTE:
The pulse cycle changes depending on rpm at idle. BATTERY VOLTAGE
(11 - 14V)
[Engine is running]
Warm-up condition
Engine speed: 2,000 rpm BATTERY VOLTAGE
(11 - 14V)
PBIB0042E
PBIB0043E
Page 1813 of 3383

EC-602Revision: November 2009
FUEL INJECTOR
2006 QX56
3. CHECK FUEL INJECTOR POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect fuel injector harness connector.
3. Turn ignition switch ON.
4. Check voltage between fuel injector terminal 1 and ground with CONSULT-II or tester.
OK or NG
OK >> GO TO 5.
NG >> GO TO 4.
4. DETECT MALFUNCTIONING PART
Check the following.
Harness connectors E2, F32
IPDM E/R connector E119
15A fuse
Harness for open or short between fuel injector and fuse
>> Repair harness or connectors.
5. CHECK FUEL INJECTOR OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between fuel injector terminal 2 and ECM terminals 21, 22, 23, 40, 41, 42, 44, 63.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 6.
NG >> Repair open circuit or short to ground or short to power in harness or connectors. Voltage: Battery voltage
BBIA0374E
PBIB0582E
Continuity should exist.
Page 1815 of 3383

EC-604Revision: November 2009
FUEL PUMP
2006 QX56
FUEL PUMPPFP:17042
DescriptionUBS00HDB
SYSTEM DESCRIPTION
*: ECM determines the start signal status by the signals of engine speed and battery voltage.
The ECM activates the fuel pump for several seconds after the ignition switch is turned ON to improve engine
startability. If the ECM receives a engine speed signal from the camshaft position sensor (PHASE), it knows
that the engine is rotating, and causes the pump to operate. If the engine speed signal is not received when
the ignition switch is ON, the engine stalls. The ECM stops pump operation and prevents battery discharging,
thereby improving safety. The ECM does not directly drive the fuel pump. It controls the ON/OFF fuel pump
relay, which in turn controls the fuel pump.
COMPONENT DESCRIPTION
A turbine type design fuel pump is used in the fuel tank.
CONSULT-II Reference Value in Data Monitor ModeUBS00HDC
Specification data are reference values.
SensorInput signal to ECMECM FunctionActuator
Crankshaft position sensor (POS)
Camshaft position sensor (PHASE) Engine speed*
Fuel pump control Fuel pump relay
Battery Battery voltage*
Condition Fuel pump operation
Ignition switch is turned to ON. Operates for 1 second.
Engine running and cranking Operates.
When engine is stopped Stops in 1.5 seconds.
Except as shown above Sto ps.
BBIA0402E
MONITOR ITEMCONDITION SPECIFICATION
FUEL PUMP RLY
For 1 second after turning ignition switch ON
Engine running or cranking ON
Except above conditions
OFF
Page 1821 of 3383
EC-610Revision: November 2009
ICC BRAKE SWITCH
2006 QX56
ICC BRAKE SWITCHPFP:25320
Component DescriptionUBS00L23
When depress on the brake pedal, ICC brake switch is turned OFF
and stop lamp switch is turned ON. ECM detects the state of the
brake pedal by this input of two kinds (ON/OFF signal)
Refer to ACS-6, "
DESCRIPTION" for the ICC function.
CONSULT-II Reference Value in Data Monitor ModeUBS00L24
Specification data are reference values.
BBIA0470E
MONITOR ITEM CONDITIONSPECIFICATION
BRAKE SW 1
(ICC brake switch)
Ignition switch: ON Brake pedal: Fully released
ON
Brake pedal: Slightly depressed OFF
BRAKE SW 2
(Stop lamp switch)
Ignition switch: ON Brake pedal: Fully released
OFF
Brake pedal: Slightly depressed ON
Page 1826 of 3383

ICC BRAKE SWITCHEC-615
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EC
Revision: November 2009 2006 QX56
7. CHECK ICC BRAKE SWITCH INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Disconnect ECM harness connector.
2. Check harness continuity between ICC brake switch terminal 2 and ECM terminal 108. Refer Wiring Diagram.
3. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 8.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
8. CHECK ICC BRAKE HOLD RELAY
Refer to EC-617, "
Component Inspection" .
OK >> GO TO 9.
NG >> Replace ICC brake hold relay.
9. CHECK ICC BRAKE SWITCH
Refer to EC-617, "
Component Inspection" .
OK or NG
OK >> GO TO 14.
NG >> Replace ICC brake switch.
10. CHECK STOP LAMP SWITCH POWER SUPPLY CIRCUIT
1. Turn ignition switch OFF.
2. Disconnect stop lamp switch harness connector.
3. Check voltage between stop lamp switch terminal 3 and ground with CONSULT -II or tester.
OK or NG
OK >> GO TO 12.
NG >> GO TO 11. Continuity should exist.
BBIA0470E
Voltage: Battery voltage
PBIB2102E