EC-112Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
ACTIVE TEST MODE
Test Item
*: Leaving cooling fan OFF with CONSULT-II while engine is running may cause the engine to overheat.
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For details, refer to EC-55, "SYSTEM READINESS TEST (SRT) CODE" .
SRT Work Support Mode
This mode enables a technician to drive a vehicle to set the SRT while monitoring the SRT status.
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
FUEL INJEC-
TION
Engine: Return to the original
trouble condition
Change the amount of fuel injec-
tion using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
Harness and connectors
Fuel injector
Air fuel ratio (A/F) sensor 1
IGNITION TIM-
ING
Engine: Return to the original
trouble condition
Timing light: Set
Retard the ignition timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
Perform Idle Air Volume Learning.
POWER BAL-
ANCE
Engine: After warming up, idle
the engine.
A/C switch OFF
Shift lever N
Cut off each injector signal one at
a time using CONSULT-II.Engine runs rough or dies.
Harness and connectors
Compression
Fuel injector
Power transistor
Spark plug
Ignition coil
COOLING FAN*
Ignition switch: ON
Turn the cooling fan ON and OFF
using CONSULT-II.Cooling fan moves and stops.
Harness and connectors
Cooling fan motor
IPDM E/R
ENG COOLANT
TEMP
Engine: Return to the original
trouble condition
Change the engine coolant tem-
perature using CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
Harness and connectors
Engine coolant temperature sen-
sor
Fuel injector
FUEL PUMP
RELAY
Ignition switch: ON (Engine
stopped)
Turn the fuel pump relay ON and
OFF using CONSULT-II and lis-
ten to operating sound.Fuel pump relay makes the operat-
ing sound.Harness and connectors
Fuel pump relay
PURG VOL
CONT/V
Engine: After warming up, run
engine at 1,500 rpm.
Change the EVAP canister purge
volume control solenoid valve
opening percent using CON-
SULT-II.Engine speed changes according to
the opening percent.Harness and connectors
Solenoid valve
FUEL/T TEMP
SEN
Change the fuel tank temperature using CONSULT-II.
VENT CON-
TROL/V
Ignition switch: ON (Engine
stopped)
Turn solenoid valve ON and OFF
with the CONSULT-II and listen
to operating sound.Solenoid valve makes an operating
sound.Harness and connectors
Solenoid valve
EC-118Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
CONSULT-II Reference Value in Data MonitorUBS00H07
Remarks:
Specification data are reference values.
Specification data are output/input values which are detected or supplied by the ECM at the connector.
* Specification data may not be directly related to their components signals/values/operations.
i.e. Adjust ignition timing with a timing light before monitoring IGN TIMING, because the monitor may show the specification data i n
spite of the ignition timing not being adjusted to the specification data. This IGN TIMING monitors the data calculated by the ECM
according to the signals input from the camshaft position sensor and other ignition timing related sensors.
MONITOR ITEM CONDITION SPECIFICATION
ENG SPEED
Run engine and compare the CONSULT-II value with tachometer indica-
tion.Almost the same speed as the
tachometer indication.
MAS A/F SE-B1
Engine: After warming up
Air conditioner switch: OFF
Shift lever: N
no loadIdle Approx. 1.1 - 1.4V
2,500 rpm Approx. 1.7 - 2.0V
B/FUEL SCHDL
Engine: After warming up
Air conditioner switch: OFF
Shift lever: N
no loadIdle 3.0 - 4.2 msec
2,000 rpm 3.0 - 4.2 msec
A/F ALPHA-B1
A/F ALPHA-B2
Engine: After warming upMaintaining engine speed at 2,000
rpm54% - 155%
COOLAN TEMP/S
Engine: After warming up More than 70°C (158°F)
A/F SEN1 (B1)
A/F SEN1 (B2)
Engine: After warming upMaintaining engine speed at 2,000
rpmFluctuated around 1.5V
HO2S2 (B1)
HO2S2 (B2)
Warm-up condition
After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no load.Revving engine from idle to 3,000 rpm
quickly.0 - 0.3V ←→ Approx. 0.6 -
1.0V
HO2S2 MNTR (B1)
HO2S2 MNTR (B2)
Warm-up condition
After keeping engine speed
between 3,500 and 4,000 rpm for
1 minute and at idle for 1 minute
under no load.Revving engine from idle to 3,000 rpm
quickly.LEAN ←→ RICH
VEH SPEED SE
Turn drive wheels and compare the CONSULT-II value with speedometer
indication.Almost the same speed as the
speedometer indication
BATTERY VOLT
Ignition switch: ON (Engine stopped) 11 - 14V
ACCEL SEN1
Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.5 - 1.0V
Accelerator pedal: Fully depressed 4.0 - 4.7V
ACCEL SEN2*
Ignition switch: ON
(Engine stopped)Accelerator pedal: Fully released 0.3 - 1.2V
Accelerator pedal: Fully depressed 3.9 - 4.8V
THRTL SEN1
THRTL SEN2*
Ignition switch: ON
(Engine stopped)
Shift lever: DAccelerator pedal: Fully released More than 0.36V
Accelerator pedal: Fully depressed Less than 4.75V
EVAP SYS PRES
Ignition switch: ON Approx. 1.8 - 4.8V
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 engineAir conditioner switch: OFF OFF
Air conditioner switch: ON
(Compressor operates.)ON
P/N POSI SW
Ignition switch: ONShift lever: P or N ON
Shift lever: Except above OFF
TROUBLE DIAGNOSIS
EC-119
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Revision: August 20072004 QX56
PW/ST SIGNALEngine: After warming up, idle
the engineSteering wheel is in neutral position.
(Forward direction)OFF
Steering wheel is turned. ON
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 engineHeater fan is operating. ON
Heater fan is not operating OFF
BRAKE SW
Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
INJ PULSE-B1
INJ PULSE-B2
Engine: After warming up
Air conditioner switch: OFF
Shift lever: N
no loadIdle 2.0 - 2.8 msec
2,000 rpm 1.9 - 2.9 msec
IGN TIMING
Engine: After warming up
Air conditioner switch: OFF
Shift lever: N
no loadIdle 14° - 18° BTDC
2,000 rpm 25° - 45° BTDC
CAL/LD VALUE
Engine: After warming up
Air conditioner switch: OFF
Shift lever: N
no loadIdle 14% - 33%
2,500 rpm 12% - 25%
MASS AIRFLOW
Engine: After warming up
Air conditioner switch: OFF
Shift lever: N
no loadIdle 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
Air conditioner switch: OFF
Shift lever: N
no loadIdle
(Accelerator pedal is not depressed
even slightly, after starting engine)0%
2,000 rpm —
AIR COND RLY
Engine: After warming up, idle
the engineAir 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 crankingON
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: OFFEngine coolant temperature is 99°C
(210°F) or lessOFF
Engine coolant temperature is
between 100°C (212°F) and 104°C
(219°F) at vehicle speed less than 40
km/h (25 MPH)ON
Engine coolant temperature is 105°C
(221°F) or moreON MONITOR ITEM CONDITION SPECIFICATION
EC-120Revision: August 2007
TROUBLE DIAGNOSIS
2004 QX56
*: Accelerator pedal position sensor 2 signal and throttle position sensor 2 signal are converted by ECM internally. Thus, they differ from
ECM terminals voltage signal.HO2S2 HTR (B1)
HO2S2 HTR (B2)
Engine speed is 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 loadON
Engine speed: Above 3,600 rpm 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 the CONSULT-II value with speedometer
indication.Almost the same speed as the
speedometer indication
TRVL AFTER MIL
Ignition switch: ONVehicle has traveled after MIL has
turned ON.0 - 65,535 km
(0 - 40,723 miles)
AC PRESS SEN
Ignition switch: ON (Engine stopped) Approx. 0V
Engine: Idle
Air conditioner switch: OFF1.0 - 4.0V
VEH SPEED SE
Turn drive wheels and compare the CONSULT-II value with speedometer
indication.Almost the same speed as the
speedometer indication
SET VHCL SPD
Engine: Running ASCD: Operating.The preset vehicle speed is
displayed.
MAIN SW
Ignition switch: ONON/OFF(MAIN) switch: Pressed ON
ON/OFF(MAIN) switch: Released OFF
CANCEL SW
Ignition switch: ONCANCEL switch: Pressed ON
CANCEL switch: Released OFF
RESUME/ACC SW
Ignition switch: ONACCEL/RESUME switch: Pressed ON
ACCEL/RESUME switch: Released OFF
SET SW
Ignition switch: ONCOAST/SET switch: Pressed ON
COAST/SET switch: Released OFF
DIST SW
Ignition switch: ONDISTANCE switch: Pressed ON
DISTANCE switch: Released OFF
BRAKE SW1
Ignition switch: ONBrake pedal: Fully released ON
Brake pedal: Slightly depressed OFF
BRAKE SW2
Ignition switch: ONBrake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
CRUISE LAMP
Ignition switch: ONON/OFF(MAIN) switch: Pressed at the
1st time → at the 2nd timeON → OFF
SET LAMP
CRUISE switch: ON
When vehicle switch is between
40 km/h (25 MPH) and 144 km/h
(89 MPH).COAST/SET switch: Pressed ON
COAST/SET switch: Released OFF MONITOR ITEM CONDITION SPECIFICATION
POWER SUPPLY AND GROUND CIRCUIT
EC-131
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Revision: August 20072004 QX56
8. CHECK ECM POWER SUPPLY CIRCUIT-II
1. Reconnect ECM harness connector.
2. Turn ignition switch ON.
3. Check voltage between IPDM E/R terminal 4 and ground with
CONSULT-II or tester.
OK or NG
OK >> Go to EC-583, "IGNITION SIGNAL" .
NG >> GO TO 9.
9. CHECK ECM POWER SUPPLY CIRCUIT-III
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON and then OFF.
3. Check voltage between ECM terminals 119, 120 and ground
with CONSULT-II or tester.
OK or NG
OK >> GO TO 17.
NG (Battery voltage does not exist.)>>GO TO 10.
NG (Battery voltage exists for more than a few seconds.)>>GO TO
17.
10. CHECK ECM POWER SUPPLY CIRCUIT-IV
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Check voltage between ECM terminal 111 and ground with
CONSULT-II or tester.
OK or NG
OK >> GO TO 11.
NG >> GO TO 12.Voltage: Battery voltage
PBIB2063E
Voltage: After turning ignition switch OFF, battery
voltage will exist for a few seconds, then
drop approximately 0V.
PBIB1630E
Voltage: Battery voltage
PBIB11 91 E
EC-144Revision: August 2007
DTC P0037, P0038, P0057, P0058 HO2S2 HEATER
2004 QX56
2. DETECT MALFUNCTIONING PART
Check the following.
Harness connectors E5, F14
IPDM E/R connector E119
10A fuse
Harness for open or short between heated oxygen sensor 2 and fuse
>> Repair harness or connectors.
3. CHECK HO2S2 OUTPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between ECM terminal and HO2S2 terminal as follows.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 4.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
4. CHECK HEATED OXYGEN SENSOR 2 HEATER
Refer to EC-145, "
Component Inspection" .
OK or NG
OK >> GO TO 5.
NG >> Replace malfunctioning heated oxygen sensor 2.
5. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END
DTCTe r m i n a l s
Bank
ECM Sensor
P0037, P0038 6 2 1
P0057, P0058 25 2 2
Continuity should exist.
EC-152Revision: August 2007
DTC P0101 MAF SENSOR
2004 QX56
6. CHECK MAF SENSOR GROUND CIRCUIT FOR OPEN AND SHORT
1. Turn ignition switch OFF.
2. Disconnect ECM harness connector.
3. Check harness continuity between MAF sensor terminal 3 and ECM terminal 67.
Refer to Wiring Diagram.
4. Also check harness for short to ground and short to power.
OK or NG
OK >> GO TO 7.
NG >> Repair open circuit or short to ground or short to power in harness or connectors.
7. CHECK MAF SENSOR INPUT SIGNAL CIRCUIT FOR OPEN AND SHORT
1. Check harness continuity between MAF sensor terminal 4 and ECM terminal 51.
Refer to Wiring Diagram.
2. 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 MASS AIR FLOW SENSOR
Refer to EC-153, "
Component Inspection" .
OK or NG
OK >> GO TO 9.
NG >> Replace mass air flow sensor.
9. CHECK INTERMITTENT INCIDENT
Refer to EC-127, "
TROUBLE DIAGNOSIS FOR INTERMITTENT INCIDENT" .
>>INSPECTION END Continuity should exist.
Continuity should exist.
DTC P0101 MAF SENSOR
EC-153
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Revision: August 20072004 QX56
Component InspectionUBS00H12
MASS AIR FLOW SENSOR
1. Reconnect all harness connectors disconnected.
2. Start engine and warm it up to normal operating temperature.
3. Check voltage between ECM terminal 51 (Mass air flow sensor
signal) and ground.
*: Check for linear voltage rise in response to engine being increased to about
4,000 rpm.
4. If the voltage is out of specification, proceed the following.
Turn ignition switch OFF.
Disconnect mass air flow sensor harness connector and reconnect it again.
Perform steps 2 and 3 again.
5. If NG, remove mass air flow sensor from air duct. Check hot wire for damage or dust.
6. If NG, clean or replace mass air flow sensor.
Removal and InstallationUBS00H13
MASS AIR FLOW SENSOR
Refer to EM-14, "AIR CLEANER AND AIR DUCT" .
Condition Voltage V
Ignition switch ON (Engine stopped.) Approx. 0.4
Idle (Engine is warmed-up to normal
operating temperature.)1.1 - 1.4
2,500 rpm (Engine is warmed-up to
normal operating temperature.)1.7 - 2.0
Idle to about 4,000 rpm* 1.1 - 1.4 to Approx. 4.0
PBIB11 06 E