2001 INFINITI QX4 ECU

Precautions for Supplemental Restraint System
(SRS) ªAIR BAGº and ªSEAT BELT
PRE-TENSIONERº
NBAT0001The supplemental Restraint System such as ªAIR BAGº and ªSEAT BELT PRE-TENSIONERº used along with
a seat belt, helps to reduce the risk or severity of injury to the driver and front passenger for certain types of
collision. The SRS system composition which is available to INFINITI QX4 is as follows:
IFor a frontal collision
The Supplemental Restraint System consists of driver air bag module (located in the center of the steer-
ing wheel), front passenger air bag module (located on the instrument panel on passenger side), seat belt
pre-tensioners, a diagnosis sensor unit, warning lamp, wiring harness and spiral cable.
IFor a side collision
The Supplemental Restraint System consists of front side air bag module (located in the outer side of front
seat), satellite sensor, diagnosis sensor unit (one of components of air bags for a frontal collision), wiring
harness, warning lamp (one of components of air bags for a frontal collision).
Information necessary to service the system safely is included in theRS sectionof this Service Manual.
WARNING:
ITo 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 performed
by an authorized INFINITI dealer.
IImproper 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 RS section.
IDo not use electrical test equipment on any circuit related to the SRS unless instructed to in this
Service Manual. Spiral cable and wiring harnesses covered with yellow insulation tape either just
before the harness connectors or for the complete harness are related to the SRS.
Precautions for On Board Diagnostic (OBD)
System of A/T and Engine
NBAT0002The ECM has an on board diagnostic system. It will light up the malfunction indicator lamp (MIL) to warn the
driver of a malfunction causing emission deterioration.
CAUTION:
IBe sure to turn the ignition switch ªOFFº and disconnect the negative battery terminal before any
repair or inspection work. The open/short circuit of related switches, sensors, solenoid valves, etc.
will cause the MIL to light up.
IBe sure to connect and lock the connectors securely after work. A loose (unlocked) connector will
cause the MIL to light up due to an open circuit. (Be sure the connector is free from water, grease,
dirt, bent terminals, etc.)
IBe sure to route and secure the harnesses properly after work. Interference of the harness with a
bracket, etc. may cause the MIL to light up due to a short circuit.
IBe sure to connect rubber tubes properly after work. A misconnected or disconnected rubber tube
may cause the MIL to light up due to a malfunction of the EGR system or fuel injection system,
etc.
IBe sure to erase the unnecessary malfunction information (repairs completed) from the TCM and
ECM before returning the vehicle to the customer.
SEF289H
PrecautionsNBAT0003IBefore connecting or disconnecting the TCM harness
connector, turn ignition switch ªOFFº and disconnect
negative battery terminal. Failure to do so may damage
the TCM. Because battery voltage is applied to TCM even
if ignition switch is turned ªOFFº.
PRECAUTIONS
Precautions for Supplemental Restraint System (SRS) ªAIR BAGº and ªSEAT BELT PRE-TENSIONERº
AT-6

SAT014K
SAT020K
DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION
PROCEDURE
NBAT0028S01CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DUREº has been previously conducted, always turn ignition
switch ªOFFº and wait at least 5 seconds before conducting
the next test.
After the repair, perform the following procedure to confirm the
malfunction is eliminated.
With CONSULT-II
1) Turn ignition switch ªONº.
2) Select ªDATA MONITORº mode for ªENGINEº with CONSULT-
II.
3) Start engine and maintain the following conditions for at least
5 consecutive seconds.
VHCL SPEED SE: 10 km/h (6 MPH) or more
THRTL POS SEN: More than 1.3V
Selector lever: D position (OD ªONº or ªOFFº)
With GST
Follow the procedure ªWith CONSULT-IIº.
DTC P0705 PARK/NEUTRAL POSITION SWITCH
Description (Cont'd)
AT-100

SAT014K
SAT971J
SAT014K
SAT020K
DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION
PROCEDURE
NBAT0034S01CAUTION:
IAlways drive vehicle at a safe speed.
IBe careful not to rev engine into the red zone on the
tachometer.
NOTE:
If ªDIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DUREº has been previously conducted, always turn ignition
switch ªOFFº and wait at least 5 seconds before conducting
the next test.
After the repair, perform the following procedure to confirm the
malfunction is eliminated.
With CONSULT-II
1) Turn ignition switch ªONº and select ªDATA MONITORº mode
for ªA/Tº with CONSULT-II.
2) Drive vehicle and check for an increase of ªVHCL/S SE´MTRº
value.
If the check result is NG, go to ªDIAGNOSTIC PROCEDUREº,
AT-200.
If the check result is OK, go to following step.
3) Select ªDATA MONITORº mode for ªENGINEº with CONSULT-
II.
4) Start engine and maintain the following conditions for at least
5 consecutive seconds.
VHCL SPEED SE: 30 km/h (19 MPH) or more
THRTL POS SEN: More than 1.2V
Selector lever: D position (OD ªONº)
Driving pattern: Driving the vehicle uphill (increased engine
load) will help maintain the driving conditions required for this
test.
If the check result is NG, go to ªDIAGNOSTIC PROCEDUREº,
AT-114.
If the check result is OK, go to following step.
5) Maintain the following conditions for at least 5 consecutive
seconds.
CMPS´RPM (REF): 3,500 rpm or more
THRTL POS SEN: More than 1.2V
Selector lever: D position (OD ªONº)
Driving pattern: Driving the vehicle uphill (increased engine
load) will help maintain the driving conditions required for this
test.
With GST
Follow the procedure ªWith CONSULT-IIº.
DTC P0720 VEHICLE SPEED SENSOR´A/T (REVOLUTION SENSOR)
Description (Cont'd)
AT-112

DescriptionNBAT0037The engine speed signal is sent from the ECM to the TCM.
TCM TERMINALS AND REFERENCE VALUENBAT0037S02Remarks: Specification data are reference values.
Terminal
No.Wire color Item ConditionJudgement
standard
(Approx.)
39 W/BEngine speed sig-
nal
Refer to EC-127, ªECM INSPECTION
TABLEº.Ð
ON BOARD DIAGNOSIS LOGICNBAT0037S03
Diagnostic trouble code Malfunction is detected when ... Check item (Possible cause)
: ENGINE SPEED SIG
TCM does not receive the proper voltage
signal from ECM.IHarness or connectors
(The sensor circuit is open or shorted.)
: P0725
SAT014K
SAT020K
DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION
PROCEDURE
NBAT0037S01CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DUREº has been previously conducted, always turn ignition
switch ªOFFº and wait at least 5 seconds before conducting
the next test.
After the repair, perform the following procedure to confirm the
malfunction is eliminated.
With CONSULT-II
1) Turn ignition switch ªONº and select ªDATA MONITORº mode
for ªENGINEº with CONSULT-II.
2) Start engine and maintain the following conditions for at least
10 consecutive seconds.
VHCL SPEED SE: 10 km/h (6 MPH) or more
THRTL POS SEN: More than 1.2V
Selector lever: D position (OD ªONº)
With GST
Follow the procedure ªWith CONSULT-IIº.
DTC P0725 ENGINE SPEED SIGNAL
Description
AT-116

ON BOARD DIAGNOSIS LOGICNBAT0066S04
Diagnostic trouble code Malfunction is detected when ... Check item (Possible cause)
: TP SEN/CIRC A/T
TCM receives an excessively low or high
voltage from the sensor.IHarness or connectors
(The solenoid circuit is open or shorted.)
IThrottle position sensor
IThrottle position switch
: P1705
SAT014K
SAT971J
SAT014K
SAT020K
DIAGNOSTIC TROUBLE CODE (DTC) CONFIRMATION
PROCEDURE
NBAT0066S01CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If ªDIAGNOSTIC TROUBLE CODE CONFIRMATION PROCE-
DUREº has been previously conducted, always turn ignition
switch ªOFFº and wait at least 5 seconds before conducting
the next test.
After the repair, perform the following procedure to confirm the
malfunction is eliminated.
With CONSULT-II
1) Turn ignition switch ªONº and select ªDATA MONITORº mode
for ªA/Tº with CONSULT-II.
2) Apply vacuum to the throttle opener, then check the following.
Refer to steps 1 and 2 of ªPreparationº, ªTCM SELF-DIAG-
NOSTIC PROCEDURE (No Tools)º, AT-46.
Accelerator pedal
conditionTHRTL POS SEN CLOSED THL/SW W/O THRL/P´SW
Fully released Less than 4.7V ON OFF
Partially
depressed0.1 - 4.6V OFF OFF
Fully depressedMore than
1.9 - 4.6VOFF ON
If the check result is NG, go to ªDIAGNOSTIC PROCEDUREº,
AT-180.
If the check result is OK, go to following step.
3) Turn ignition switch ªONº and select ªDATA MONITORº mode
for ªENGINEº with CONSULT-II.
4) Start engine and maintain the following conditions for at least
3 consecutive seconds. Then release accelerator pedal com-
pletely.
VHCL SPEED SE: 10 km/h (6 MPH) or more
THRTL POS SEN: Approximately 3V or less
Selector lever: D position (OD ªONº)
If the check result is NG, go to ªDIAGNOSTIC PROCEDUREº,
AT-180.
If the check result is OK, go to following step.
5) Maintain the following conditions for at least 3 consecutive
seconds. Then release accelerator pedal completely.
VHCL SPEED SE: 10 km/h (6 MPH) or more
Accelerator pedal: Wide open throttle
Selector lever: D position (OD ªONº)
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
DTC P1705 THROTTLE POSITION SENSOR
Description (Cont'd)
AT-177

ComponentsNBAT0097
SAT147K
CAUTION:
IInstall key interlock cable in such a way that it will not be
damaged by sharp bends, twists or interference with adja-
cent parts.
IAfter installing key interlock cable to control device, make
sure that casing cap and bracket are firmly secured in
their positions. If casing cap can be removed with an
external load of less than 39.2 N (4.0 kg, 8.8 lb), replace
key interlock cable with new one.
SAT353I
RemovalNBAT0098Unlock slider from adjuster holder and remove rod from cable.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
KEY INTERLOCK CABLE
Components
AT-271

RemovalNBAT0214
SAT362IA
SAT163K
CAUTION:
When removing the A/T assembly from engine, first remove
the crankshaft position sensor (OBD) from the A/T assembly
lower side.
Be careful not to damage sensor edge.
Ð 4WD MODEL ÐNBAT0214S011. Remove battery negative terminal.
2. Remove exhaust front and rear tubes.
3. Remove fluid charging pipe from A/T assembly.
4. Remove oil cooler pipe from A/T assembly.
5. Plug up openings such as the fluid charging pipe hole, etc.
6. Remove propeller shaft. Refer to PD-4, ªComponentsº.
7. Remove transfer control linkage from transfer. Refer to TF-119,
ªRemovalº.
IInsert plug into rear oil seal after removing rear propeller
shaft.
IBe careful not to damage spline, sleeve yoke and rear oil
seal.
8. Remove A/T control cable from A/T assembly.
9. Disconnect A/T solenoid, PNP switch, turbine revolution, revo-
lution and speedometer sensor harness connectors.
SAT148K
10. Remove starter motor. Refer to SC-18, ªRemoval and Installa-
tionº.
11. Remove bolts securing torque converter to drive plate.
IRemove the bolts by turning crankshaft.
GI
MA
EM
LC
EC
FE
TF
PD
AX
SU
BR
ST
RS
BT
HA
SC
EL
IDX
REMOVAL AND INSTALLATION
Removal
AT-277

SAT801C
12. Support A/T and transfer assembly with a jack.
13. Remove rear engine mounting member from body and A/T
assembly. Tighten rear engine mounting member to the speci-
fied torque. Refer to EM-59, ªRear Engine Mountingº.
14. Remove bolts securing A/T assembly to engine.
ISecure torque converter to prevent it from dropping.
ISecure A/T assembly to a jack.
15. Lower A/T assembly with transfer.
SAT553J
SAT544J
Ð 2WD MODEL ÐNBAT0214S02CAUTION:
IDo not attach lifting cable to or place supporting fixture
under companion flange at rear of A/T (shown in the fig-
ure at left) when lifting/lowering A/T.
IBe sure to attach lifting cable to rear engine mounting or
dynamic damper location when lifting/lowering A/T.
1. Remove battery negative terminal.
2. Remove exhaust front and rear tubes.
3. Remove fluid charging pipe from A/T assembly.
4. Remove oil cooler pipe from A/T assembly.
5. Plug up openings such as the fluid charging pipe hole, etc.
6. Remove propeller shaft. Refer to PD-4, ªComponentsº.
7. Remove A/T control cable from A/T assembly.
8. Disconnect A/T and speedometer sensor harness connectors.
9. Remove starter motor. Refer to SC-18, ªRemoval and Installa-
tionº.
10. Remove gusset and rear plate cover securing engine to A/T
assembly.
11. Remove bolts securing torque converter to drive plate.
IRemove the bolts by turning crankshaft.
12. Support A/T assembly with a jack.
13. Remove rear engine mounting member from body and A/T
assembly. Tighten rear engine mounting member to the speci-
fied torque. Refer to EM-59, ªRear Engine Mountingº.
14. Remove bolts securing A/T assembly to engine.
15. Pull A/T assembly backwards.
ISecure torque converter to prevent it from dropping.
ISecure A/T assembly to a jack.
16. Lower A/T assembly.
SAT977H
InstallationNBAT0107IDrive plate runout
Maximum allowable runout:
Refer to EM-70, ªFLYWHEEL/DRIVE PLATE RUNOUTº.
If this runout is out of specification, replace drive plate with ring
gear.
REMOVAL AND INSTALLATION
Removal (Cont'd)
AT-278