2005 INFINITI QX4 ECU

ACS-40
[ICC]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: October 20052005 QX56
2. DIAGNOSIS CHECK 2
With CONSULT-II
Perform self-diagnosis of ABS actuator and electric unit (control unit). Is malfunction indicated?
YES or NO
YES >> Repair or replace as necessary. Erase DTC and perform ICC system running test. Refer to ACS-
9, "ICC System Running Test" . Then perform self-diagnosis of ICC system again.
NO >> Replace ICC unit. Refer to ACS-60, "
ICC Unit" . Erase DTC and perform ICC system running test.
Refer to ACS-9, "
ICC System Running Test" . Then perform self-diagnosis of ICC system again.
DTC 45 BRAKE SW/STOP L SWEKS00BM6
1. CHECK CONNECTORS FOR ICC UNIT
1. Turn ignition switch OFF.
2. Disconnect ICC unit connectors and connect them securely again. Erase DTC, then perform self-diagno-
sis of ICC system again.
OK or NG
OK >>
Poor connector connection.

Check connectors. Check connectors housing for disconnected, loose, bent, and collapsed ter-
minals. If any malfunction is detected, repair as necessary. Erase DTC and perform ICC system
running test. Refer to ACS-9, "
ICC System Running Test" . Then perform self-diagnosis of ICC
system again.
NG >> GO TO 2.
2. CHECK STOP LAMP SWITCH AND ICC BRAKE SWITCH
With CONSULT-II
With data monitor, check if “STOP LAMP SW” and “BRAKE SW” are operating normally.
OK or NG
OK >> Replace ICC unit. Refer to ACS-60, "ICC Unit" . Erase DTC and perform ICC system running test.
Refer to ACS-9, "
ICC System Running Test" . Then perform self-diagnosis of ICC system again.
NG >>

BRAKE SW: GO TO 3.

STOP LAMP SW: GO TO 5.
3. ICC BRAKE SWITCH INSTALLATION AND ADJUSTMENT INSPECTION
Check ICC brake switch for proper installation and adjust if necessary. Refer to BR-6, "
BRAKE PEDAL" .
OK or NG
OK >> GO TO 4.
NG >> After adjustment, erase DTC and perform ICC system running test. Refer to ACS-9, "
ICC System
Running Test" . Then perform self-diagnosis of ICC system again.
4. CHECK ICC BRAKE SWITCH
Check ICC brake switch. Refer to ACS-59, "
ICC Brake Switch and Stop Lamp Switch" .
OK or NG
OK >> Replace ICC unit. Refer to ACS-60, "ICC Unit" . Erase DTC and perform ICC system running test.
Refer to ACS-9, "
ICC System Running Test" . Then perform self-diagnosis of ICC system again.
NG >> Replace ICC brake switch. Erase DTC and perform ICC system running test. Refer to ACS-9,
"ICC System Running Test" . Then perform self-diagnosis of ICC system again.

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
ACS-41
[ICC]
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5. CHECK STOP LAMP ILLUMINATION
Check stop lamp illumination.
OK or NG
OK >> GO TO 6.
NG >>

Check stop lamp circuit. Refer to LT- 1 0 3 , "STOP LAMP" .

Erase DTC and perform ICC system running test. Refer to ACS-9, "ICC System Running Test"
. Then perform self-diagnosis of ICC system again.
6. CHECK ICC BRAKE HOLD RELAY
1. Turn ignition switch OFF.
2. Remove ICC brake hold relay.
3. Check continuity between ICC brake hold relay terminals.
OK or NG
OK >> GO TO 7.
NG >> Replace ICC brake hold relay. Erase DTC and perform
ICC system running test. Refer to ACS-9, "
ICC System
Running Test" . Then perform self-diagnosis of ICC sys-
tem again.
7. CHECK ICC BRAKE HOLD RELAY CIRCUIT
1. Disconnect ICC unit and stop lamp switch connectors.
2. Check continuity between ICC unit harness connector B17 ter-
minal 38 (R/G) and ICC brake hold relay harness connector
E134 terminal 7 (R/G).
3. Check continuity between ICC unit harness connector B17 ter-
minal 38 (R/G) and stop lamp switch harness connector E38 ter-
minal 4 (R/G).
OK or NG
OK >> Replace ICC unit. Refer to ACS-60, "ICC Unit" . Erase
DTC and perform ICC system running test. Refer to ACS-9, "
ICC System Running Test" . Then
perform self-diagnosis of ICC system again.
NG >>

Repair harness between ICC unit and ICC brake hold relay or stop lamp switch.

Erase DTC and perform ICC system running test. Refer to ACS-9, "ICC System Running Test"
. Then perform self-diagnosis of ICC system again.
DTC 46 OPERATION SW CIRCEKS00BM7
1. CHECK ECM CONNECTOR
1. Turn ignition switch OFF.
2. Disconnect ECM connector and connect it securely again. Erase DTC, then perform self-diagnosis of ICC
system again.
OK or NG
OK >>
Poor connector connection.

Check connector. Check connector housing for disconnected, loose, bent, and collapsed termi-
nals. If any malfunction is detected, repair as as necessary. Erase DTC and perform ICC sys- 7 - 6 Continuity should not exist.
4 - 3 Continuity should exist.
SKIA6651E
Continuity should exist.
Continuity should exist.
WKIA3403E

ACS-48
[ICC]
TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
Revision: October 20052005 QX56
17. CHECK ICC UNIT STANDARD VOLTAGE
With CONSULT-II
1. Connect stop lamp switch connector.
2. While performing active test (STOP LAMP: STP LMP DRIVE
ON) with CONSULT-II, check voltage between ICC unit harness
connector B17 terminal 29 (BR/W) and ground.
OK or NG
OK >> Replace ICC unit. Refer to ACS-60, "ICC Unit" . Erase
DTC and perform ICC system running test. Refer to
ACS-9, "
ICC System Running Test" . Then perform self-
diagnosis of ICC system again.
NG >> Replace stop lamp switch. Erase DTC and perform ICC
system running test. Refer to ACS-9, "
ICC System Running Test" . Then perform self-diagnosis of
ICC system again.
DTC 92 ECM CIRCUITEKS00BMA
1. DIAGNOSIS CHECK 1
With CONSULT-II
Perform self-diagnosis with CONSULT-II. Is “CAN COMM CIRCUIT” indicated?
YES or NO
YES >> Repair or replace as necessary. Erase DTC and perform ICC system running test. Refer to ACS-
9, "ICC System Running Test" . Then perform self-diagnosis of ICC system again.
NO >> GO TO 2.
2. DIAGNOSIS CHECK 2
With CONSULT-II
Perform ECM self-diagnosis with CONSULT-II. Is malfunction indicated?
YES or NO
YES >> Repair or replace as necessary. Erase DTC and perform ICC system running test. Refer to ACS-
9, "ICC System Running Test" . Then perform self-diagnosis of ICC system again.
NO >> Replace ICC unit. Refer to ACS-60, "
ICC Unit" . Erase DTC and perform ICC system running test.
Refer to ACS-9, "
ICC System Running Test" . Then perform self-diagnosis of ICC system again.
DTC 96 NP RANGEEKS00BMB
1. CHECK ICC UNIT CONNECTORS
1. Turn ignition switch OFF.
2. Disconnect ICC unit harness connectors and connect them securely again. Erase DTC, then perform self-
diagnosis of ICC system again.
OK or NG
OK >> GO TO 2.
NG >>

Poor connector connection.

Check connector. Check connector housing for disconnected, loose, bent, and collapsed termi-
nals. If any malfunction is detected, repair as necessary. Erase DTC and perform ICC system
running test. Refer to ACS-9, "
ICC System Running Test" . Then perform self-diagnosis of ICC
system again. 29 - Ground Approx. 0V (during active test)
SKIA1200E

PRECAUTIONS
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PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
ECS00CDJ
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. This system includes seat belt switch inputs and dual stage front air bag modules. The SRS
system uses the seat belt switches to determine the front air bag deployment, and may only deploy one front
air bag, depending on the severity of a collision and whether the front occupants are belted or unbelted.
Information necessary to service the system safely is included in the SRS and SB section of this Service Man-
ual.
WA RN ING:

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.
Precautions for On Board Diagnostic (OBD) System of A/T and EngineECS00CDK
The 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:

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 MIL to light up.

Be 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.)

Be 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.

Be 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.

Be sure to erase the unnecessary malfunction information (repairs completed) from the TCM and
ECM before returning the vehicle to the customer.

AT-50
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
Inspections Before Trouble DiagnosisECS00CEE
A/T FLUID CHECK
Fluid Leakage and Fluid Level Check

Inspect for fluid leakage and check the fluid level. Refer to AT - 1 3 , "Checking A/T Fluid" .
Fluid Condition Check
Inspect the fluid condition.
STALL TEST
Stall Test Procedure
1. Inspect the amount of engine oil. Replenish the engine oil if necessary.
2. Drive for about 10 minutes to warm up the vehicle so that the A/
T fluid temperature is 50 to 80°C (122 to 176°F). Inspect the
amount of ATF. Replenish if necessary.
3. Securely engage the parking brake so that the tires do not turn.
4. Engine start, apply foot brake, and place selector lever in “D”
position.
5. While holding down the foot brake, gradually press down the
accelerator pedal.
6. Quickly read off the stall speed, then quickly remove your foot
from the accelerator pedal.
CAUTION:
Do not hold down the accelerator pedal for more than 5 sec-
onds during this test.
7. Move the selector lever to the “N” position.
8. Cool down the ATF.
Fluid condition Conceivable Cause Required Operation
Varnished (viscous
varnish state)Clutch, brake
scorchedReplace the ATF and check the A/T
main unit and the vehicle for mal-
functions (wire harnesses, cooler
pipes, etc.)
Milky white or
cloudyWater in the fluidReplace the ATF and check for
places where water is getting in.
Large amount of
metal powder mixed
inUnusual wear of
sliding parts within
A/TReplace the ATF and check for
improper operation of the A/T.
SAT6 3 8A
SAT6 4 7B
SCIA1224E
SAT5 1 4G

AT-52
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
3. After warming up remove the oil pressure detection plug and
install the oil pressure gauge [ST2505S001(J-34301-C)].
CAUTION:
When using the oil pressure gauge, be sure to use the O-
ring attached to the oil pressure detection plug.
4. Securely engage the parking brake so that the tires do not turn.
5. Start the engine, then measure the line pressure at both idle and
the stall speed.
CAUTION:

Keep the brake pedal pressed all the way down during
measurement.

When measuring the line pressure at the stall speed,
refer to AT-5 0, "
STALL TEST" .
6. After the measurements are complete, install the oil pressure
detection plug and tighten to the regulation torque below.
CAUTION:
Do not reuse the O-ring.
Line Pressure
SCIA5309E
SCIA1224E
:7.3 N·m (0.74 kg-m, 65 in-lb)SAT4 9 3G
Engine speedLine pressure [kPa (kg/cm
2 , psi)]
R position D position
At idle speed 392 - 441 (4.0 - 4.5, 57 - 64) 373 - 422 (3.8 - 4.3, 54 - 61)
At stall speed 1,700 - 1,890 (17.3 - 19.3, 247 - 274) 1,310 - 1,500 (13.3 - 15.3, 190 - 218)

TROUBLE DIAGNOSIS
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CONSULT-II Function (A/T)ECS00CEP
CONSULT-II can display each diagnostic item using the diagnostic test modes shown following.
CONSULT-II REFERENCE VALUE
NOTICE:
1. The CONSULT-II electrically displays shift timing and lock-up timing (that is, operation timing of each sole-
noid).
Check for time difference between actual shift timing and the CONSULT-II display. If the difference is
noticeable, mechanical parts (except solenoids, sensors, etc.) may be malfunctioning. Check mechanical
parts using applicable diagnostic procedures.
2. Shift schedule (which implies gear position) displayed on CONSULT-II and that indicated in Service Man-
ual may differ slightly. This occurs because of the following reasons:
–Actual shift schedule has more or less tolerance or allowance,
–Shift schedule indicated in Service Manual refers to the point where shifts start, and
–Gear position displayed on CONSULT-II indicates the point where shifts are completed.
3. Display of solenoid valves on CONSULT-II changes at the start of shifting, while gear position is displayed
upon completion of shifting (which is computed by TCM).
TCM diagnostic mode Description
WORK SUPPORTSupports inspections and adjustments. Commands are transmitted to the TCM for setting the status
suitable for required operation, input/output signals are received from the TCM and received data is
displayed.
SELF-DIAG RESULTS Displays TCM self-diagnosis results.
DATA MONITOR Displays TCM input/output data in real time.
CAN DIAG SUPPORT MNTR The result of transmit/receive diagnosis of CAN communication can be read.
ACTIVE TEST Operation of electrical loads can be checked by sending drive signal to them.
FUNCTION TESTConducted by CONSULT-II instead of a technician to determine whether each system is “OK” or
“NG”.
ECU PART NUMBER TCM part number can be read.
Item name Condition Display value (Approx.)
AT F T E M P S E 1
0°C (32° F) - 20°C (68°F) - 80°C (176°F)2.2 - 1.8 - 0.6 V
AT F T E M P S E 22.2 - 1.7 - 0.45 V
TCC SOLENOIDWhen perform slip lock-up 0.2 - 0.4 A
When perform lock-up 0.4 - 0.6 A
SLCT LVR POSISelector lever in “N”,“P” position. N/P
Selector lever in “R” position. R
Selector lever in “D” position. D
Selector lever in “4” position. 4
Selector lever in “3” position. 3
Selector lever in “2” position. 2
Selector lever in “1” position. 1
VHCL/S SE·A/T During drivingApproximately matches the
speedometer reading.
ENGINE SPEED Engine runningClosely matches the tachometer
reading.
LINE PRES SOL During driving 0.2 - 0.6 A
TURBINE REV During driving (lock-up ON)Approximately matches the
engine speed.
VHCL/S SE·MTR During drivingApproximately matches the
speedometer reading.

TROUBLE DIAGNOSIS
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DATA MONITOR MODE
Operation Procedure
1. Perform “CONSULT-II SETTING PROCEDURE”. Refer to AT-85, "CONSULT-II SETTING PROCEDURE"
.
2. Touch “DATA MONITOR”.
NOTE:
When malfunction is detected, CONSULT-II performs
“REAL-TIME DIAGNOSIS”. Also, any malfunction detected
while in this mode will be displayed at real time.
Display Items List
X: Standard, —: Not applicable
BCIA0031E
Monitored item (Unit)Monitor Item Selection
Remarks ECU
INPUT
SIGNALSMAIN SIG-
NALSSELEC-
TION
FROM
MENU
VHCL/S SE·A/T (km/h) X X X Revolution sensor
VHCL/S SE·MTR (km/h) X — X
ACCELE POSI (0.0/8) X — X Accelerator pedal position signal
THROTTLE POSI (0.0/8) X X XDegree of opening for accelerator recognized by
the TCM
For fail-safe operation, the specific value used
for control is displayed.
CLSD THL POS (ON-OFF display) X — X
Signal input with CAN communications
W/O THL POS (ON-OFF display) X — X
BRAKE SW (ON-OFF display) X — X Stop lamp switch
GEAR — X XGear position recognized by the TCM updated
after gear-shifting
ENGINE SPEED (rpm) X X X
TURBINE REV (rpm) X X X
OUTPUT REV (rpm) X X X
GEAR RATIO — X X
TC SLIP SPEED (rpm) — X XDifference between engine speed and torque
converter input shaft speed
F SUN GR REV (rpm) — — X
F CARR GR REV (rpm) — — X
AT F T E M P S E 1 ( V ) X — X
AT F T E M P S E 2 ( V ) X — X
AT F T E M P 1 (°C) — X X
AT F T E M P 2 (°C) — X X
BATTERY VOLT (V) X — X
ATF PRES SW 1 (ON-OFF display) X X X (for FR/B solenoid)
ATF PRES SW 2 (ON-OFF display) X X X (for LC/B solenoid)
ATF PRES SW 3 (ON-OFF display) X X X (for I/C solenoid)
ATF PRES SW 5 (ON-OFF display) X X X (for D/C solenoid)