2008 NISSAN TEANA engine

EC-94
< FUNCTION DIAGNOSIS >[VQ25DE, VQ35DE]
VARIABLE INDUCTION AIR SYSTEM
In the medium speed range, the power valves are closed. Under this condition, the pressure waves of the
exhaust stroke do not disturb the pressure waves of the intake stroke of each opposite bank. Therefore, charg-
ing efficiency is increased together with the effect of the long intake passage.
However, in the high speed range, the power valves are open. Under this condition, the pressure waves of
intake stroke are resonant with those of each opposite bank exhaust stroke. Therefore, charging efficiency is
also increased.
In addition, both valves (valves 1 and 2 for VQ35DE engine and a valve for VQ25DE engine) are opened or
closed in other ranges mentioned above. Thus maximum charging efficiency is obtained for the various driving
conditions.
VACUUM HOSE DRAWING (VQ35DE engine)
VACUUM HOSE DRAWING (VQ25DE engine)
1. Power valve actuator 1 2. VIAS control solenoid valve 1 3. VIAS control solenoid valve 2
4. Power valve actuator 2 5. Intake manifold collector
JMBIA0172ZZ

EC-96
< FUNCTION DIAGNOSIS >[VQ25DE, VQ35DE]
VARIABLE INDUCTION AIR SYSTEM
Component Parts Location
INFOID:0000000003860679
1. Intake valve timing control solenoid
valve (bank 1)2. Intake valve timing control solenoid
valve (bank 2)3. Electronic controlled engine mount
control solenoid valve
4. Fuel injector (bank 2) 5. Cooling fan motor-2 6. A/F sensor 1 (bank 2)
7. Ignition coil (with power transistor)
and spark plug (bank 2)8. Camshaft position sensor (PHASE)
(bank 2)9. Crankshaft position sensor (POS)
10. Engine coolant temperature sensor 11. Cooling fan motor-1 12. ECM
13. Refrigerant pressure sensor 14. Battery current sensor 15. IPDM E/R
16. Mass air flow sensor (with intake air
temperature sensor)17. Electric throttle control actuator 18. Power valve actuator 2 (VQ35DE
models)
19. EVAP canister purge volume control
solenoid valve20. Camshaft position sensor (PHASE)
(bank 1)21. Ignition coil (with power transistor)
and spark plug (bank 1)
22. A/F sensor 1 (bank 1) 23. Fuel injector (bank 1) 24. VIAS control solenoid valve 1 and 2
(VQ35DE models)
25. Power valve actuator 1
JMBIA1373ZZ

VARIABLE INDUCTION AIR SYSTEM
EC-99
< FUNCTION DIAGNOSIS >[VQ25DE, VQ35DE]
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1. A/F sensor 1 (bank 1) harness con-
nector2. A/F sensor 1 (bank 1) 3. A/F sensor 1 (bank 2) harness con-
nector
4. A/F sensor 1 (bank 2)
: Vehicle front
1. HO2S2 (bank 1) 2. HO2S2 (bank 2) 3. HO2S2 (bank 2) harness connector
4. Tie-rod (RH) 5. Power steering pressure sensor 6. HO2S2 (bank 1) harness connector
: Vehicle front
1. Electronic controlled engine mount
control solenoid valve2. VIAS control solenoid valve 1 3. VIAS control solenoid valve 2
4. EVAP canister purge volume control
solenoid valve
JMBIA1116ZZ
JMBIA1380ZZ
JMBIA1381GB

EC-100
< FUNCTION DIAGNOSIS >[VQ25DE, VQ35DE]
VARIABLE INDUCTION AIR SYSTEM
1. Electronic controlled engine mount
control solenoid valve2. VIAS control solenoid valve 3. EVAP canister purge volume control
solenoid valve
1. Intake valve timing control solenoid
valve (bank 1)2. Intake valve timing control solenoid
valve (bank 2)3. Data link connector
1. Stop lamp switch 2. ASCD brake switch 3. Accelerator pedal position sensor
1. ASCD steering switch 2. CANCEL switch 3. RESUME/ACCELERATE switch
4. SET/COAST switch 5. MAIN switch
JMBIA1382GB
JMBIA1383ZZ
JMBIA1384ZZ
JMBIA1120ZZ

VARIABLE INDUCTION AIR SYSTEM
EC-101
< FUNCTION DIAGNOSIS >[VQ25DE, VQ35DE]
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Component DescriptionINFOID:0000000003856501
1. Fuel level sensor unit and fuel pump
harness connector2. Fuel pressure regulator 3. Fuel level sensor unit and fuel pump
: Vehicle front
JMBIA1385ZZ
Component Reference
Accelerator pedal position sensorEC-304, "
Description"
Camshaft position sensor (PHASE)EC-222, "Description"
Crankshaft position sensor (POS)EC-218, "Description"
Engine coolant temperature sensorEC-157, "Description"
Mass air flow sensorEC-149, "Description"
Throttle position sensorEC-160, "Description"
Power valve 1 and 2EC-351, "Description"
VIAS control solenoid valve 1EC-285, "Description"
VIAS control solenoid valve 2EC-288, "Description"

EC-102
< FUNCTION DIAGNOSIS >[VQ25DE, VQ35DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
ON BOARD DIAGNOSTIC (OBD) SYSTEM
Diagnosis DescriptionINFOID:0000000003856502
INTRODUCTION
The ECM has an on board diagnostic system, which detects malfunctions related to engine sensors or actua-
tors. The ECM also records various emission-related diagnostic information including:
The above information can be checked using procedures listed in the table below.
×: Applicable —: Not applicable
*: When DTC and 1st trip DTC simultaneously appear on the display, they cannot be clearly distinguished from each other.
The malfunction indicator MI on the instrument panel illuminates when the same malfunction is detected in two
consecutive trips (Two trip detection logic), or when the ECM enters fail-safe mode. (Refer to EC-386, "
Fail
safe".)
TWO TRIP DETECTION LOGIC
When a malfunction is detected for the first time, 1st trip DTC and 1st trip Freeze Frame data are stored in the
ECM memory. The MI will not illuminate at this stage. <1st trip>
If the same malfunction is detected again during the next drive, the DTC and Freeze Frame data are stored in
the ECM memory, and the MI illuminates. The MI illuminates at the same time the DTC is stored. <2nd trip>
The “trip” in the “Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed during
vehicle operation. Specific on board diagnostic items will cause the ECM to illuminate or blink the MI, and
store DTC and Freeze Frame data, even in the 1st trip, as shown below.
×: Applicable —: Not applicable
DTC AND FREEZE FRAME DATA
DTC and 1st Trip DTC
Emission-related diagnostic information Diagnostic service
Diagnostic Trouble Code (DTC) Service $03 of ISO 15031-5
Freeze Frame data Service $02 of ISO 15031-5
System Readiness Test (SRT) code Service $01 of ISO 15031-5
1st Trip Diagnostic Trouble Code (1st Trip DTC) Service $07 of ISO 15031-5
1st Trip Freeze Frame data —
Test values and Test limits Service $06 of ISO 15031-5
Calibration ID Service $09 of ISO 15031-5
DTC 1st trip DTCFreeze
Frame data1st trip Freeze
Frame dataSRT code SRT status Test value
CONSULT-III×× × × × ×—
GST×× ×—×××
ECM××*— — —×—
ItemsMI DTC 1st trip DTC
1st trip 2nd trip
1st trip
displaying2nd trip
displaying1st trip
displaying2nd trip
display-
ing BlinkingIlluminat-
edBlinkingIlluminat-
ed
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0306 is
being detected×———— —×—
Misfire (Possible three way catalyst
damage) — DTC: P0300 - P0306 is
being detected——×——×——
One trip detection diagnoses (Re-
fer to EC-389, "
DTCIndex".)—×——×———
Except above — — —×—××—

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-103
< FUNCTION DIAGNOSIS >[VQ25DE, VQ35DE]
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The 1st trip DTC (whose number is the same as the DTC number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously, and the 1st trip DTC did not recur, the 1st trip DTC
will not be displayed.
If a malfunction is detected during the 1st trip, the 1st trip DTC is saved in the ECM memory. The MI will not
illuminate (two trip detection logic). If the same malfunction 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 saved in the ECM memory and the MI illuminates. In other words,
the DTC is stored in the ECM memory and the MI illuminates when the same malfunction occurs in two con-
secutive 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. For malfunctions that blink or illuminate the MI during the
1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
Procedures for clearing the DTC and the 1st trip DTC from the ECM memory are described in “How to Erase
DTC and 1st Trip DTC”.
For malfunctions in which 1st trip DTCs are displayed, refer to “EMISSION-RELATED DIAGNOSTIC INFOR-
MATION ITEMS”. These items are required by legal regulations to continuously monitor the system/compo-
nent. In addition, the items monitored non-continuously are also displayed on CONSULT-III.
1st trip DTC is specified in Service $07 of ISO 15031-5. 1st trip DTC detection occurs without illuminating the
MI and therefore does not warn the driver of a malfunction. However, 1st trip DTC detection will not prevent
the vehicle from being tested, for example during Inspection/Maintenance (I/M) tests.
When a 1st trip DTC is detected, check, print out or write down and erase (1st trip) DTC and Freeze Frame
data as specified in Work Flow procedure Step 2, refer to EC-7, "
Work Flow". Then perform DTC Confirmation
Procedure or Component Function Check to try to duplicate the malfunction. If the malfunction is duplicated,
the item requires repair.
Freeze Frame Data and 1st Trip Freeze Frame Data
The ECM records the driving conditions such as fuel system status, calculated load value, engine coolant tem-
perature, short-term fuel trim, long-term fuel trim, engine speed, vehicle speed, absolute throttle position, base
fuel schedule and intake air temperature at the moment a malfunction is detected.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data.
The data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-III or
GST. The 1st trip freeze frame data can only be displayed on the CONSULT-III screen, not on the GST.
Only one set of freeze frame data (either 1st trip freeze frame data or freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MI on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
For example, the EGR malfunction (Priority: 2) was detected and the freeze frame data was saved in the 2nd
trip. After that when the misfire (Priority: 1) is detected in another trip, the freeze frame data will be updated
from the EGR malfunction to the misfire. The 1st trip freeze frame data is updated each time a different mal-
function is detected. There is no priority for 1st trip freeze frame data. However, once freeze frame data is
stored in the ECM memory, 1st trip freeze data is no longer stored (because only one freeze frame data or 1st
trip freeze frame data can be stored in the ECM). If freeze frame data is stored in the ECM memory and freeze
frame data with the same priority occurs later, the first (original) freeze frame data remains unchanged in the
ECM memory.
Both 1st trip freeze frame data and freeze frame data (along with the DTCs) are cleared when the ECM mem-
ory is erased. Procedures for clearing the ECM memory are described in “How to Erase DTC and 1st Trip
DTC”.
How to Read DTC and 1st Trip DTC
With CONSULT-III
With GST
CONSULT-III or GST (Generic Scan Tool) Examples: P0340, P0850, P1148, etc.
These DTCs are prescribed by ISO 15031-6.
Priority Items
1Freeze frame data Misfire — DTC: P0300 - P0306
Fuel Injection System Function — DTC: P0171, P0172, P0174, P0175
2 Except the above items (Includes CVT related items)
3 1st trip freeze frame data

EC-104
< FUNCTION DIAGNOSIS >[VQ25DE, VQ35DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
(CONSULT-III also displays the malfunctioning component or system.)
No Tools
The number of blinks of the MI in the Diagnostic Test Mode II (Self-Diagnostic Results) indicates the DTC.
Example: 0340, 0850, 1148, etc.
These DTCs are controlled by NISSAN.
1st trip DTC No. is the same as DTC No.
Output of a DTC indicates a malfunction. However, GST or the Diagnostic Test Mode II do not indi-
cate whether the malfunction is still occurring or has occurred in the past and has returned to nor-
mal. CONSULT-III can identify malfunction status as shown below. Therefore, using CONSULT-III (if
available) is recommended.
DTC or 1st trip DTC of a malfunction is displayed in SELF-DIAGNOSTIC RESULTS mode of CONSULT-III.
Time data indicates how many times the vehicle was driven after the last detection of a DTC.
If the DTC is being detected currently, the time data will be [0].
If a 1st trip DTC is stored in the ECM, the time data will be [1t].
How to Erase DTC and 1st Trip DTC
With CONSULT-III
NOTE:
 If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.
 If the DTC is not for CVT related items (see EC-389
), skip step 1.
1. Erase DTC in TCM. Refer to TM-35, "
Diagnosis Description".
2. Select “ENGINE” with CONSULT-III.
3. Select “SELF-DIAG RESULTS”.
4. Touch “ERASE”. (DTC in ECM will be erased.)
WITH GST
NOTE:
 If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.
1. Select Service $04 with GST (Generic Scan Tool).
No Tools
NOTE:
 If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.
1. Erase DTC in ECM. Refer to How to Erase Diagnostic Test Mode II (Self-diagnostic Results).
If the battery is disconnected, the emission-related diagnostic information will be cleared within 24
hours.
The following data are cleared when the ECM memory is erased.
- Diagnostic trouble codes
- 1st trip diagnostic trouble codes
- Freeze frame data
- 1st trip freeze frame data
- System readiness test (SRT) codes
- Test values
Actual work procedures are explained using a DTC as an example. Be careful so that not only the DTC, but all
of the data listed above, are cleared from the ECM memory during work procedures.
SYSTEM READINESS TEST (SRT) CODE
System Readiness Test (SRT) code is specified in Service $01 of ISO 15031-5.
As part of an enhanced emissions test for Inspection & Maintenance (I/M), certain states require the status of
SRT be used to indicate whether the ECM has completed self-diagnosis of major emission systems and com-
ponents. Completion must be verified in order for the emissions inspection to proceed.
If a vehicle is rejected for a State emissions inspection due to one or more SRT items indicating “INCMP”, use
the information in this Service Manual to set the SRT to “CMPLT”.
In most cases the ECM will automatically complete its self-diagnosis cycle during normal usage, and the SRT
status will indicate “CMPLT” for each application system. Once set as “CMPLT”, the SRT status remains
“CMPLT” until the self-diagnosis memory is erased.
Occasionally, certain portions of the self-diagnostic test may not be completed as a result of the customer's
normal driving pattern; the SRT will indicate “INCMP” for these items.
NOTE: