ECO mode INFINITI QX56 2009 Factory Service Manual

EC-282
< COMPONENT DIAGNOSIS >[VK56DE]
P0605 ECM
P0605 ECM
Component DescriptionINFOID:0000000003771563
The ECM consists of a microcomputer and connectors for signal
input and output and for power supply. The ECM controls the engine.
On Board Diagn
osis LogicINFOID:0000000003771564
This self-diagnosis has one or two trip detection logic.
FAIL-SAFE MODE
ECM enters fail-safe mode when the malfunction A is detected.
DTC Confirmation ProcedureINFOID:0000000003771565
Perform PROCEDURE FOR MALFUNCTION A first. If th e 1st trip DTC cannot be confirmed, perform
PROCEDURE FOR MALFUNCTION B. If there is no malfunction on PROCEDURE FOR MALFUNCTION
B, perform PROCEDURE FOR MALFUNCTION C.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
PROCEDURE FOR MALFUNCTION A
1. Turn ignition switch ON.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-283, "Diagnosis Procedure"
PROCEDURE FOR MALFUNCTION B
1. Turn ignition switch ON and wait at least 1 second.
2. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
3. Check 1st trip DTC.
4. If 1st trip DTC is detected, go to EC-283, "Diagnosis Procedure"
.
PROCEDURE FOR MALFUNCTION C
1. Turn ignition switch ON and wait at least 1 second.
2. Turn ignition switch OFF, wait at least 10 seconds and then turn ON.
PBIB1164E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0605
0605 Engine control module A) ECM calculation function is malfunctioning.
ECM
B) ECM EEP-ROM system is malfunctioning.
C) ECM self shut-off function is malfunctioning.
Detected items Engine operation condition in fail-safe mode
Malfunction A  ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx.
5 degrees) by the return spring.
 ECM deactivates ASCD operation.
Revision: December 20092009 QX56

P0643 SENSOR POWER SUPPLYEC-285
< COMPONENT DIAGNOSIS > [VK56DE]
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P0643 SENSOR POWER SUPPLY
On Board Diagnosis LogicINFOID:0000000003771567
This self-diagnosis has the on
e trip detection logic.
FAIL-SAFE MODE
When the malfunction is detected, ECM ent ers fail-safe mode and the MIL lights up.
DTC Confirmation ProcedureINFOID:0000000003771568
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 10V at idle.
1. Start engine and let it idle for 1 second.
2. Check DTC.
3. If DTC is detected, go to EC-285, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771569
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body. Refer to EC-85, "Ground Inspection"
.
OK or NG
OK >> GO TO 2.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0643
0643 Sensor power supply circuit
short ECM detects a voltage of power source
for sensor is excessively low or high.  Harness or connectors
(APP sensor 1 circuit is shorted.)
(PSP sensor circuit is shorted.)
(Battery current sensor circuit is shorted.)
(Refrigerant pressure se nsor circuit is short-
ed.)
(EVAP control system pressure sensor circuit
is shorted.)
 Accelerator pedal position sensor
 Power steering pressure sensor
 Refrigerant pressure sensor
 EVAP control system pressure sensor
Engine operation condition in fail-safe mode
ECM stops the electric throttle control actuator control, throttle valve is maintained at a fixed opening (approx. 5 degrees) b y the return
spring.
BBIA0354E
Revision: December 20092009 QX56

EC-288
< COMPONENT DIAGNOSIS >[VK56DE]
P0850 PNP SWITCH
P0850 PNP SWITCH
Component DescriptionINFOID:0000000003771570
When the selector lever position is P or N, trans
mission range signal from the TCM is sent to ECM.
On Board Diagnosis LogicINFOID:0000000003771571
DTC Confirmation ProcedureINFOID:0000000003771572
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
WITH CONSULT-III
1. Turn ignition switch ON.
2. Select “P/N POSI SW” in “DATA MONITOR” mode wit h CONSULT-III. Then check the “P/N POSI SW” sig-
nal under the following conditions.
If NG, go to EC-289, "Diagnosis Procedure"
.
If OK, go to following step.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Start engine and warm it up to normal operating temperature.
5. Maintain the following conditions for at least 60 consecutive seconds.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to EC-289, "Diagnosis Procedure"
.
Overall Function CheckINFOID:0000000003771573
Use this procedure to check the overall function of t he transmission range signal circuit. During this check, a
1st trip DTC might not be confirmed.
WITH GST
1. Turn ignition switch ON.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0850
0850 Park/neutral position
switch The transmission range signal is not changed in
the process of engine starting and driving.  Harness or connectors
[The transmission range signal circuit is
open or shorted.]
 Combination meter
TCM
Position (Selector lever) Known-good signal
N or P position ON
Except the above position OFF
ENG SPEED 1,000 - 6,375 rpm
COOLAN TEMP/S More than 70 °C (158 °F)
B/FUEL SCHDL 2.0 - 31.8 msec
VHCL SPEED SE More than 64 km/h (40 MPH)
Selector lever Suitable position
Revision: December 20092009 QX56

P1140, P1145 IVT CONTROL POSITION SENSOR
EC-291
< COMPONENT DIAGNOSIS > [VK56DE]
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P1140, P1145 IVT CONTROL POSITION SENSOR
Component DescriptionINFOID:0000000003771575
Intake valve timing control position sensors are located in the front of
cylinder heads in both bank 1 and bank 2.
This sensor uses a Hall IC.
The cam position is determined by the intake camshaft sprocket con-
cave (in four places). The ECM provides feedback to the intake valve
timing control for appropriate target valve open-close timing accord-
ing to drive conditions based on detected cam position.
On Board Diagnosis LogicINFOID:0000000003771576
DTC Confirmation ProcedureINFOID:0000000003771577
1. If DTC Confirmation Procedure has been previously c
onducted, always perform the following before con-
ducting the next step.
a. Turn ignition switch OFF and wait at least 10 seconds.
b. Turn ignition switch ON.
c. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-III.
4. Maintain the following conditions for at least 10 seconds.
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to EC-291, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771578
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
SEF359Z
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1140
11 4 0
(Bank 1)
Intake valve timing control
position sensor circuit An excessively high or low voltage from the
sensor is sent to ECM.  Harness or connectors
(Intake valve timing control position
sensor circuit is open or shorted)
 Intake valve timing control position sensor
 Crankshaft position sensor (POS)
 Camshaft positi on sensor (PHASE)
 Accumulation of debris to the signal pick-up portion of the camshaft sprock-
et
P1145
11 4 5
(Bank 2)
ENG SPEED More th
an idle speed
Selector lever P or N position
Revision: December 20092009 QX56

EC-306
< COMPONENT DIAGNOSIS >[VK56DE]
P1421 COLD START CONTROL
P1421 COLD START CONTROL
DescriptionINFOID:0000000003771601
ECM controls ignition timing and engine idle speed when engine is started with prewarming up condition.
This control promotes the activation of three way ca
talyst by heating the catalyst and reduces emissions.
On Board Diagnosis LogicINFOID:0000000003771602
DTC Confirmation ProcedureINFOID:0000000003771603
NOTE:
 If DTC Confirmation Procedure has been previously conducted, always perform the following before con-
ducting the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
 If DTC P1421 is displayed with other DTC, firs t perform the trouble diagnosis for other DTC.
TESTING CONDITION:
Before performing the following procedure, confirm that battery voltage is more than 11V at idle.
1. Turn ignition switch OFF and wait at least 10 seconds.
2. Turn ignition switch ON.
3. Select “DATA MONITOR” mode with CONSULT-IIl.
4. Check that the “COOLAN TEMP/S” indication is between 4 °C (39 °F) and 36 °C (97 °F).
If “COOLAN TEMP/S” indication is within t he specified value, go to the following step.
If “COOLANT TEMP/S” indication is out of the s pecified value, cool engine down or warm engine up and
go to step 1.
5. Start engine and let it idle for 5 minutes.
6. Check 1st trip DTC.
7. If 1st trip DTC is detected, go to EC-306, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771604
1.PERFORM IDLE AIR VOLUME LEARNING
Perform EC-18, "Idle Air Volume Learning"
.
Is Idle Air Volume Lear ning carried out successfully?
Ye s o r N o
Ye s > > G O T O 2 .
No >> Follow the instruction of Idle Air Volume Learning.
2.CHECK INTAKE SYSTEM
Check for the cause of intake air volume lacking. Refer to the following.
 Crushed intake air passage
 Intake air passage clogging
OK or NG
OK >> GO TO 3.
NG >> Repair or replace malfunctioning part
3.CHECK FUEL INJECTION SYSTEM FUNCTION
Perform EC-169, "DTC Confirmation Procedure"
in DTC P0171, P0174 FUEL INJECTION SYSTEM FUNC-
TION.
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1421
1421 Cold start emission reduction
strategy monitoring ECM does not control ignition timing and engine
idle speed properly when engine is started with
prewarming up condition.  Lack of intake air volume
 Fuel injection system
ECM
Revision: December 20092009 QX56

EC-320
< COMPONENT DIAGNOSIS >[VK56DE]
P1554 BATTERY CURRENT SENSOR
P1554 BATTERY CURRENT SENSOR
Component DescriptionINFOID:0000000003771620
The power generation voltage variable control enables fuel con-
sumption to be decreased by reducing the engine load which is
caused by the power generation of the generator. The battery cur-
rent sensor (1) is installed to the battery cable at the negative termi-
nal. The sensor measures the charging/discharging current of the
battery. Based on the sensor signal, ECM judges whether or not the
power generation voltage variable control is performed. When per-
forming the power generation voltage variable control, ECM calcu-
lates the target power generation voltage based on the sensor
signal. And ECM sends the calculated value as the power genera-
tion command value to IPDM E/R. For the details of the power gen-
eration voltage variable control, refer to
CHG-7, "System
Description".
: Vehicle front
CAUTION:
Do not connect the electrical compon ent or the ground wire directly to the battery terminal. The con-
nection causes the malfunction of th e power generation voltage variable control, and then the battery
discharge may occur.
On Board Diagn osis LogicINFOID:0000000003771621
The MIL will not light up for this self-diagnosis.
NOTE:
If DTC P1554 is displayed with DTC P0643, first pe rform the trouble diagnosis for DTC P0643. Refer to
EC-285, "On Board Diagnosis Logic"
.
Overall Function CheckINFOID:0000000003771622
Use this procedure to check the overall function of the bat tery current sensor circuit. During this check, a 1st
trip DTC might not be confirmed.
TESTING CONDITION:
 Before performing the following procedure, confirm th at battery voltage is more than 12.8V at idle.
 Before performing the following procedure, confi rm that all load switches and A/C switch are turned
OFF.
WITH CONSULT-III
1. Start engine and let it idle.
2. Select “BAT CUR SEN” in “DATA MONITOR” mode with CONSULT-III.
3. Check “BAT CUR SEN” indication for 10 seconds.
“BAT CUR SEN” should be above 2,300mV at least once.
4. If NG, go to EC-321, "Diagnosis Procedure"
.
WITH GST
1. Start engine and let it idle.
BBIA0744E
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P1554
1554 Battery current sensor performance The output voltage of the battery current
sensor is lower than the specified value
while the battery voltage is high enough.  Harness or connectors
(The sensor circuit is open or shorted.)
 Battery current sensor
Revision: December 20092009 QX56

P1572 ICC BRAKE SWITCHEC-333
< COMPONENT DIAGNOSIS > [VK56DE]
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P1572 ICC BRAKE SWITCH
Component DescriptionINFOID:0000000003771638
When the brake pedal is depressed, 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
CCS-13
for the ICC function.
On Board Diagnosis LogicINFOID:0000000003771639
This diagnosis has the on e trip detection logic.
 The MIL will not light up for this self-diagnosis.
NOTE:
 If DTC P1572 is displayed with DT C P0605, first perform the trouble diagnosis for DTC P0605. Refer
to EC-282, "On Board Diagnosis Logic"
.
 This self-diagnosis has the one trip detection logic. When malfunction A is detected, DTC is not
stored in ECM memory. And in that case, 1st trip DTC and 1st trip freeze frame data are displayed.
1st trip DTC is erased when igniti on switch OFF. And even when ma lfunction A is detected in two
consecutive trips, DTC is not stored in ECM memory.
DTC Confirmation ProcedureINFOID:0000000003771640
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
 Procedure for malfunction B is not described here. It takes extremely long time to complete procedure for
malfunction B. By performing procedure for malfunction A, the incident that causes malfunction B can be
detected.
 If DTC Confirmation Procedure has been previously c onducted, always perform the following before con-
ducting the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Steps 4 and 7 may be conducted with the drive wheels li fted in the shop or by driving the vehicle. If a
road test is expected to be easier, it is unnecessary to lift the vehicle.
1. Start engine (VDC switch OFF).
2. Select “DATA MONITOR” mode with CONSULT-IIl.
3. Press MAIN switch and make sure that CRUISE lamp lights up.
4. Drive the vehicle for at least 5 consec utive seconds under the following conditions.
BBIA0470E
DTC No.Trouble diagnosis
name DTC detecting condition Possible cause
P1572
1572 ICC brake switch A)
When vehicle speed is above 30 km/h (19
MPH), ON signals from the stop lamp
switch and the ICC brake switch are sent to
ECM at the same time.  Harness or connectors
(The stop lamp switch circuit is shorted.)
 Harness or connectors
(The ICC brake switch circuit is shorted.)
Stop lamp switch
 ICC brake switch
 ICC brake hold relay
 Incorrect stop lamp switch installation
 Incorrect ICC brake switch installation
ECM
B)
ICC brake switch signal is not sent to ECM
for extremely long time while the vehicle is
driving
Revision: December 20092009 QX56

EC-334
< COMPONENT DIAGNOSIS >[VK56DE]
P1572 ICC BRAKE SWITCH
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to
EC-334, "Diagnosis Procedure"
.
If 1st trip DTC is not detec ted, go to the following step.
7. Drive the vehicle for at least 5 consec utive seconds under the following conditions.
8. Check 1st trip DTC.
9. If 1st trip DTC is detected, go to EC-334, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771641
1.CHECK OVERALL FUNCTION-I
With CONSULT-IIl
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DAT A MONITOR” mode with CONSULT-IIl.
3. Check “BRAKE SW1” indication under the following conditions.
Without CONSULT-IIl
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 108 and ground under the following conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2.CHECK OVERALL FUNCTION-II
With CONSULT-IIl
Check “BRAKE SW2” indication in “DATA MONITOR” mode.
Without CONSULT-IIl
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
Driving location Depress the brake pedal for more than
five seconds so as not to come off from
the above-mentioned vehicle speed.
CONDITION INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
CONDITION VOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage
MBIB0061E
CONDITION INDICATION
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
Revision: December 20092009 QX56

P1572 ASCD BRAKE SWITCHEC-339
< COMPONENT DIAGNOSIS > [VK56DE]
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P1572 ASCD BRAKE SWITCH
Component DescriptionINFOID:0000000003771643
When the brake pedal is depressed,
ASCD 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 EC-33, "System Description"
for the ASCD function.
On Board Diagnosis LogicINFOID:0000000003771644
This self-diagnosis has the one trip detection logic.
 The MIL will not light up for this self-diagnosis.
NOTE:
 If DTC P 1572 is displayed with DTC P0605, first pe rform the trouble diagnosis for DTC P0605. Refer
to EC-282, "On Board Diagnosis Logic"
.
 This self-diagnosis has the one trip detection logic. When malfunction A is detected, DTC is not
stored in ECM memory. And in that case, 1st trip DTC and 1st trip freeze frame data are displayed.
1st trip DTC is erased when igniti on switch OFF. And even when ma lfunction A is detected in two
consecutive trips, DTC is not stored in ECM memory.
DTC Confirmation ProcedureINFOID:0000000003771645
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
 Procedure for malfunction B is not described here. It takes extremely long time to complete procedure for malfunction B. By performing procedure for malfunction A, the incident that causes malfunction B can be
detected.
 If DTC Confirmation Procedure has been previously c onducted, always perform the following before con-
ducting the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Steps 4 and 7 may be conducted with the drive wheels li fted in the shop or by driving the vehicle. If a
road test is expected to be easier, it is unnecessary to lift the vehicle.
1. Start engine (VDC switch OFF).
2. Select “DATA MONITOR” mode with CONSULT-III.
3. Press MAIN switch and make sure that CRUISE indicator lights up.
4. Drive the vehicle for at least 5 consecutive seconds under the following condition.
BBIA0373E
DTC No. Trouble Diagnosis
Name DTC Detecting Condition Possible Cause
P1572
1572 ASCD brake switch A)
When the vehicle speed is above 30km/h (19
MPH), ON signals from the stop lamp switch
and the ASCD brake switch are sent to ECM
at the same time.  Harness or connectors
(The stop lamp switch circuit is shorted.)
 Harness or connectors
(The ASCD brake switch circuit is shorted.)
 Stop lamp switch
 ASCD brake switch
 Incorrect stop lamp switch installation
 Incorrect ASCD brake switch installation
ECM
B)
ASCD brake switch signal is not sent to ECM
for extremely long time while the vehicle is
driving
Revision: December 20092009 QX56

EC-340
< COMPONENT DIAGNOSIS >[VK56DE]
P1572 ASCD BRAKE SWITCH
5. Check 1st trip DTC.
6. If 1st trip DTC is detected, go to
EC-340, "Diagnosis Procedure"
.
If 1st trip DTC is not detec ted, go to the following step.
7. Drive the vehicle for at least 5 consecutive seconds under the following condition.
8. Check 1st trip DTC.
9. If 1st trip DTC is detected, go to EC-340, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771646
1.CHECK OVERALL FUNCTION-I
With CONSULT-III
1. Turn ignition switch ON.
2. Select “BRAKE SW1” in “DAT A MONITOR” mode with CONSULT-III.
3. Check “BRAKE SW1” indication under the following conditions.
Without CONSULT-III
1. Turn ignition switch ON.
2. Check voltage between ECM terminal 108 and ground under the
following conditions.
OK or NG
OK >> GO TO 2.
NG >> GO TO 3.
2.CHECK OVERALL FUNCTION-II
With CONSULT-III
Check “BRAKE SW2” indication in “DATA MONITOR” mode.
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
VHCL SPEED SE More than 30 km/h (19 MPH)
Selector lever Suitable position
Driving location Depress the brake pedal for more than
five seconds so as not to come off from
the above-mentioned condition.
CONDITION INDICATION
Brake pedal: Slightly depressed OFF
Brake pedal: Fully released ON
CONDITION VOLTAGE
Brake pedal: Slightly depressed Approximately 0V
Brake pedal: Fully released Battery voltage
MBIB0061E
CONDITION INDICATION
Brake pedal: Fully released OFF
Brake pedal: Slightly depressed ON
Revision: December 20092009 QX56