HO2S2 HEATER
EC-319
[QR]
C
D
E
F
G
H
I
J
K
L
MA
EC
HO2S2 HEATERPFP:226A0
DescriptionBBS005JA
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated oxygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
CONSULT-II Reference Value in Data Monitor ModeBBS005JB
Specification data are reference values.
Sensor Input Signal to ECM ECM Function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS)Engine speed
Heated oxygen sensor 2
heater controlHeated oxygen sensor 2 heater
Engine coolant temperature sensor Engine coolant temperature
Mass air flow sensor Amount of intake air
Engine speed rpm Heated oxygen sensor 2 heater
Above 3,800 OFF
Below 3,800 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
MONITOR ITEM CONDITION SPECIFICATION
HO2S2 HTR (B1)
Engine speed: Below 3,800 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 3,800 rpm OFF
EC-324
[QR]
IAT SENSOR
IAT SENSORPFP:22630
Component DescriptionBBS005JG
The intake air temperature sensor is built into mass air flow sensor.
The sensor detects intake air temperature and transmits a signal to
the ECM.
The temperature sensing unit uses a thermistor which is sensitive to
the change in temperature. Electrical resistance of the thermistor
decreases in response to the temperature rise.
*: These data are reference values and are measured between ECM terminal 34
(Intake air temperature sensor) and ground.
CAUTION:
Do not use ECM ground terminals when measuring input/output
voltage. Doing so may result in damage to the ECM's transistor.
Use a ground other than ECM terminals, such as the ground.
PBIB1604E
Intake air
temperature°C (°F)Voltage* V Resistance kΩ
25 (77) 3.3 1.800 - 2.200
80 (176) 1.2 0.283 - 0.359
SEF012P
PRECAUTIONS
EC-351
[VQ]
C
D
E
F
G
H
I
J
K
L
MA
EC
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
BBS004XC
The Supplemental Restraint System such as “AIR BAG” and “SEAT BELT PRE-TENSIONER”, used along
with a front seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain
types of collision. Information necessary to service the system safely is included in the SRS and SB section of
this Service Manual.
WARNING:
To avoid rendering the SRS inoperative, which could increase the risk of personal injury or death
in the event of a collision which would result in air bag inflation, all maintenance must be per-
formed by an authorized NISSAN/INFINITI dealer.
Improper maintenance, including incorrect removal and installation of the SRS, can lead to per-
sonal injury caused by unintentional activation of the system. For removal of Spiral Cable and Air
Bag Module, see the SRS section.
Do not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. SRS wiring harnesses can be identified by yellow and/or orange harnesses or
harness connectors.
On Board Diagnostic (OBD) System of EngineBBS004XD
The ECM has an on board diagnostic system. It will light up the malfunction indicator (MI) to warn the driver of
a malfunction causing emission deterioration.
CAUTION:
Be sure to turn the ignition switch OFF and disconnect the negative battery cable before any
repair or inspection work. The open/short circuit of related switches, sensors, solenoid valves,
etc. will cause the MI to light up.
Be sure to connect and lock the connectors securely after work. A loose (unlocked) connector will
cause the MI to light up due to the open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)
Certain systems and components, especially those related to OBD, may use a new style slide-
locking type harness connector. For description and how to disconnect, refer to PG-71, "
HAR-
NESS CONNECTOR" .
Be sure to route and secure the harnesses properly after work. The interference of the harness
with a bracket, etc. may cause the MI to light up due to the short circuit.
Be sure to erase the unnecessary malfunction information (repairs completed) from the ECM
before returning the vehicle to the customer.
PrecautionBBS004XE
Always use a 12 volt battery as power source.
Do not attempt to disconnect battery cables while engine is
running.
Before connecting or disconnecting the ECM harness con-
nector, turn ignition switch OFF and disconnect negative
battery cable. Failure to do so may damage the ECM
because battery voltage is applied to ECM even if ignition
switch is turned OFF.
Before removing parts, turn ignition switch OFF and then
disconnect negative battery cable.
SEF289H
BASIC SERVICE PROCEDURE
EC-381
[VQ]
C
D
E
F
G
H
I
J
K
L
MA
EC
BASIC SERVICE PROCEDUREPFP:00018
Basic InspectionBBS004Y0
1. INSPECTION START
1. Check service records for any recent repairs that may indicate a related malfunction, or a current need for
scheduled maintenance.
2. Open engine hood and check the following:
–Harness connectors for improper connections
–Wiring harness for improper connections, pinches and cut
–Vacuum hoses for splits, kinks and improper connections
–Hoses and ducts for leaks
–Air cleaner clogging
–Gasket
3. Confirm that electrical or mechanical loads are not applied.
–Headlamp switch is OFF.
–Air conditioner switch is OFF.
–Rear window defogger switch is OFF.
–Steering wheel is in the straight-ahead position, etc.
4. Start engine and warm it up until engine coolant temperature
indicator points the middle of gauge.
Ensure engine stays below 1,000 rpm.
5. Run engine at about 2,000 rpm for about 2 minutes under no
load.
6. Make sure that no DTC is displayed with CONSULT-II or ECM
[Diagnostic Test Mode II (Self-diagnostic results)]
OK or NG
OK >> GO TO 3.
NG >> GO TO 2.
2. REPAIR OR REPLACE
Repair or replace components as necessary according to corresponding Diagnostic Procedure.
>> GO TO 3.
SEF983U
SEF976U
SEF977U
EC-394
[VQ]
TROUBLE DIAGNOSIS
TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionBBS004Y6
INTRODUCTION
The engine has an ECM to control major systems such as fuel con-
trol, ignition control, idle air control system, etc. The ECM accepts
input signals from sensors and instantly drives actuators. It is essen-
tial that both input and output signals are proper and stable. At the
same time, it is important that there are no malfunctions such as vac-
uum leaks, fouled spark plugs, or other malfunctions with the engine.
It is much more difficult to diagnose an incident that occurs intermit-
tently rather than continuously. Most intermittent incidents are
caused by poor electric connections or improper wiring. In this case,
careful checking of suspected circuits may help prevent the replace-
ment of good parts.
A visual check only may not find the cause of the incidents. A road
test with CONSULT-II or a circuit tester connected should be per-
formed. Follow the Work Flow on EC-395, "
WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such incidents, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A Diagnostic Worksheet like the example
on EC-399, "
Worksheet Sample" should be used.
Start your diagnosis by looking for conventional malfunctions first.
This will help troubleshoot driveability malfunctions on an electroni-
cally controlled engine vehicle.
MEF036D
SEF233G
SEF234G
TROUBLE DIAGNOSIS
EC-421
[VQ]
C
D
E
F
G
H
I
J
K
L
MA
EC
51 W Mass air flow sensor[Ignition switch: ON]Approximately 0.4V
[Engine is running]
Warm-up condition
Idle speed0.9 - 1.1V (VQ23DE engine)
1.0 - 1.3V (VQ35DE engine)
[Engine is running]
Warm-up condition
Engine is revving from idle to about 4,000
rpm0.9 - 1.1 to Approx. 2.4
(VQ23DE engine)
1.0 - 1.3 to Approx. 2.4
(VQ35DE engine)
(Check for linear voltage rise in
response to engine being
increased to about 4,000 rpm.)
55 WHeated oxygen sensor 2
(Bank 2)[Engine is running]
Revving engine from idle up to 3,000 rpm
quickly 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 load0 - Approximately 1.0V
60
61
62P/W
L/R
Y/RIgnition signal No. 5
Ignition signal No. 3
Ignition signal No. 1[Engine is running]
Warm-up condition
Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle0 - 0.3V
[Engine is running]
Warm-up condition
Engine speed: 2,500 rpm0.1 - 0.6V
66 LSensor ground
(Throttle position sensor)[Engine is running]
Warm-up condition
Idle speedApproximately 0V
67 Y Sensor ground[Engine is running]
Warm-up condition
Idle speedApproximately 0V
68 LSensor power supply
(PSP sensor)[Ignition switch: ON]Approximately 5V
69 G Throttle position sensor 2[Ignition switch: ON]
Engine: Stopped
Shift lever: D
Accelerator pedal: Fully releasedLess than 4.75V
[Ignition switch: ON]
Engine: Stopped
Shift lever: D
Accelerator pedal: Fully depressedMore than 0.36V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
SEC986C
SEC987C
TROUBLE DIAGNOSIS
EC-433
[VQ]
C
D
E
F
G
H
I
J
K
L
MA
EC
*: Leaving cooling fan OFF with CONSULT-II while engine is running may cause the engine to overheat.
REAL TIME DIAGNOSIS IN DATA MONITOR MODE (RECORDING VEHICLE DATA)
Description
CONSULT-II has two kinds of triggers and they can be selected by touching “SETTING” in “DATA MONITOR”
mode.
1. “AUTO TRIG” (Automatic trigger):
The malfunction will be identified on the CONSULT-II screen
in real time.
In other words, DTC/1st trip DTC and malfunction item will be
displayed if the malfunction is detected by ECM.
At the moment a malfunction is detected by ECM, “MONI-
TOR” in “DATA MONITOR” screen is changed to “Recording
Data ... xx%” as shown in the figure, and the data after the
malfunction detection is recorded. Then when the percentage
reached 100%, “REAL-TIME DIAG” screen is displayed. If
“STOP” is touched on the screen during “Recording Data ...
xx%”, “REAL-TIME DIAG” screen is also displayed.
The recording time after the malfunction detection and the
recording speed can be changed by “TRIGGER POINT” and
“Recording Speed”. Refer to CONSULT-II Operation Manual.
2. “MANU TRIG” (Manual trigger):
DTC/1st trip DTC and malfunction item will not be displayed
automatically on CONSULT-II screen even though a malfunc-
tion is detected by ECM.
DATA MONITOR can be performed continuously even though
a malfunction is detected.
Operation
1. “AUTO TRIG”
While trying to detect the DTC/1st trip DTC by performing the DTC Confirmation Procedure, be sure to
select to “DATA MONITOR (AUTO TRIG)” mode. You can confirm the malfunction at the moment it is
detected.
While narrowing down the possible causes, CONSULT-II should be set in “DATA MONITOR (AUTO
TRIG)” mode, especially in case the incident is intermittent.
VIAS SOL VALVE
Ignition switch: ON
Turn solenoid valve “ON” and
“OFF” using CONSULT-II and lis-
ten to operating sound.Solenoid valve makes the operating
sound.Harness and connectors
Solenoid valve
ENGINE
MOUNTING
Ignition switch: ON
Turn electronic controlled engine
mount “IDLE” and “TRVL” with
the CONSULT-II.Electronic controlled engine mount
makes the operating sound.Harness and connectors
Electronic controlled engine
mount
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
V/T ASSIGN
ANGLE
Engine: Return to the original
trouble condition
Change intake valve timing using
CONSULT-II.If trouble symptom disappears, see
CHECK ITEM.
Harness and connectors
Intake valve timing control sole-
noid valve TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
PBIB1593E
SEF707X
DTC P0102, P0103 MAF SENSOR
EC-469
[VQ]
C
D
E
F
G
H
I
J
K
L
MA
EC
Specification data are reference values and are measured between each terminal and ground.
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.
Diagnostic ProcedureBBS004Z9
1. INSPECTION START
Which malfunction (P0102 or P0103) is duplicated?
P0102 or P0103
P0102 >> GO TO 2.
P0103 >> GO TO 3.
2. CHECK INTAKE SYSTEM
Check the following for connection.
Air duct
Va c u u m h o s e s
Intake air passage between air duct and intake manifold
OK or NG
OK >> GO TO 3.
NG >> Reconnect the parts.
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
51 W Mass air flow sensor[Ignition switch: ON]Approximately 0.4V
[Engine is running]
Warm-up condition
Idle speed0.9 - 1.1V (VQ23DE engine)
1.0 - 1.3V (VQ35DE engine)
[Engine is running]
Warm-up condition
Engine is revving from idle to about 4,000
rpm0.9 - 1.1 to Approx. 2.4
(VQ23DE engine)
1.0 - 1.3 to Approx. 2.4
(VQ35DE engine)
(Check for linear voltage rise in
response to engine being
increased to about 4,000 rpm.)
67 B Sensor ground[Engine is running]
Warm-up condition
Idle speedApproximately 0V
111 W / BECM relay
(Self shut-off)[Engine is running]
[Ignition switch: OFF]
For a few seconds after turning ignition
switch OFF0 - 1.5V
[Ignition switch: OFF]
More than a few seconds after turning igni-
tion switch OFFBATTERY VOLTAGE
(11 - 14V)
11 9
120R/G
R/GPower supply for ECM[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)