2005 INFINITI QX4 ESP

BRC-32
[VDC/TCS/ABS]
TROUBLE DIAGNOSIS
Revision: October 20052005 QX56
Note 1. If wheel sensor 2 for each wheel is indicated, check ABS actuator and electric unit (control unit) power
supply voltage in addition to wheel sensor circuit check.
Note 2. If multiple malfunctions are detected including CAN communication line [U1000], perform diagnosis for
CAN communication line first.
Note 3: "ACTUATOR RLY" on the CONSULT-II self-diagnosis results indicates the malfunction of the actuator
motor relay or circuit.
DATA MONITOR
Operation Procedure
1. After turning OFF the ignition switch, connect CONSULT-II and the CONSULT-II CONVERTER to the data
link connector.
LATERAL G-SENSOR
[C1146]Lateral G-sensor is malfunctioning, or signal line of lateral G-sen-
sor is open or shorted.BRC-42, "Ya w R a t e /
Side/Decel G Sensor
System Inspection"
BR FLUID LEVEL LOW
[C1155]Brake fluid level drops or circuit between ABS actuator and elec-
tric unit (control unit) and brake fluid level switch is open or
shorted.BRC-47, "Brake Fluid
Level Sensor System
Inspection"
ENGIN SIGNAL 1
[C1130]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunction-
ing.
BRC-39, "
Engine Sys-
tem Inspection"
ENGIN SIGNAL 2
[C1131]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunction-
ing.
ENGIN SIGNAL 3
[C1132]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunction-
ing.
ENGIN SIGNAL 4
[C1133]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunction-
ing.
ENGIN SIGNAL 6
[C1136]Based on the signal from ECM, ABS actuator and electric unit
(control unit) judges that engine fuel cut system is malfunction-
ing.
ACTR RELAY CIRCUIT
[C1140]ABS actuator relay or circuit malfunction.BRC-44, "
Actuator
Motor, Motor Relay, and
Circuit Inspection"
PRESS SENSE CIRCUIT
[C1142]ABS pressure sensor circuit malfunction.BRC-51, "Pressure Sen-
sor System Inspection"
ABS VARIANT CODING
[C1170]V coding is not malfunctioning.BRC-40, "ABS/TCS/
VDC Control Unit
Inspection"
ACTIVE BOOSTER SOLENOID
NG
[C1178]Active booster solenoid is malfunctioning, or signal line of active
booster servo is open or shorted.BRC-49, "Active Booster
System Inspection"
DELTA S SEN NG
[C1179]Delta stroke sensor malfunctioning, or signal line of delta stroke
sensor is open or shorted.BRC-50, "Delta Stroke
Sensor System Inspec-
tion"
ACTIVE BOOSTER RESPONSE
NG
[C1181]Active booster response is malfunctioning, or signal line of active
booster response is open or shorted.BRC-49, "Active Booster
System Inspection"
BRAKE RELEASE SW NG
[C1184]Brake release switch is malfunctioning, or signal line of brake
release switch is open or shorted.
BRC-44, "
Actuator
Motor, Motor Relay, and
Circuit Inspection"
ACC CU INTERNAL NG
[C1185]ICC control unit internal malfunction.
BRAKE BOOSTER DEFECT
[C1189]Brake booster is defective or malfunctioning. Self-diagnostic item Malfunction detecting condition Check system

TROUBLE DIAGNOSIS FOR SELF-DIAGNOSTIC ITEMS
BRC-49
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Active Booster System InspectionEFS004Y1
INSPECTION PROCEDURE
1. DISPLAY SELF DIAGNOSIS RESULTS
Check self-diagnosis results.
Is the above displayed in the self-diagnosis display items?
YES or NO
YES >> GO TO 2.
NO >> Inspection End.
2. CONNECTOR INSPECTION
1. Turn the ignition switch OFF.
2. Disconnect the active booster connector E49 and ABS actuator and electric unit (control unit) connector
E125 and inspect the terminals for deformation, disconnection, looseness, or damage.
OK or NG
OK >> GO TO 3.
NG >> Repair connector.
3. ACTIVE BOOSTER CIRCUIT INSPECTION
1. Measure the continuity between the ABS actuator and electric unit (control unit) connector E125 and
active booster connector E49.
2. Measure the continuity between the ABS actuator and electric unit (control unit) connector E125 and body
ground.
OK or NG
OK >> GO TO 4.
NG >> Repair or replace harness or connector.
Self-diagnosis results
ACTIVE BOOSTER SOLENOID NG
ACTIVE BOOSTER RESPONSE NG
BRAKE RELEASE SW NG
BRAKE BOOSTER DEFECT
ABS actuator and electric unit
(control unit) connector E125Active booster connector
E49Continuity
17 (W/R) 3 (W/R)
Ye s 27 (L/B) 1 (L/B)
28 (Y/B) 5 (Y/B)
30 (LG/R) 2 (LG/R)
31 (W/G) 4 (W/G)
ABS actuator and electric unit
(control unit) connector E125Body ground Continuity
17 (W/R)
—No 27 (L/B)
28 (Y/B)
30 (LG/R)
31 (W/G)

EC-16Revision: October 2005
PRECAUTIONS
2005 QX56
PRECAUTIONSPFP:00001
Precautions for Supplemental Restraint System (SRS) “AIR BAG” and “SEAT
BELT PRE-TENSIONER”
UBS00KZ0
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.
WAR NIN G:

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 Engine and A/TUBS00KZ1
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 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-67, "
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 MIL to light up due to the 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 the malfunction of the EVAP system or fuel injection system,
etc.

Be sure to erase the unnecessary malfunction information (repairs completed) from the ECM and
TCM (Transmission control module) before returning the vehicle to the customer.
PrecautionUBS00KZ2

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 battery ground cable.
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
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If, during the state emissions inspection, the SRT indicates “CMPLT” for all test items, the inspector will con-
tinue with the emissions test. However, if the SRT indicates “INCMP” for one or more of the SRT items the
vehicle is returned to the customer untested.
NOTE:
If MIL is ON during the state emissions inspection, the vehicle is also returned to the customer untested even
though the SRT indicates “CMPLT” for all test items. Therefore, it is important to check SRT (“CMPLT”) and
DTC (No DTCs) before the inspection.
SRT Item
The table below shows required self-diagnostic items to set the SRT to “CMPLT”.
*: If completion of several SRTs is required, perform driving patterns (DTC confirmation procedure), one by one based on the priority for
models with CONSULT-II.
SRT Set Timing
SRT is set as “CMPLT” after self-diagnosis has been performed one or more times. Completion of SRT is
done regardless of whether the result is OK or NG. The set timing is different between OK and NG results and
is shown in the table below.
OK: Self-diagnosis is carried out and the result is OK.SRT item
(CONSULT-II indication)Performance
Priority*Required self-diagnostic items to set the SRT to “CMPLT”Corresponding
DTC No.
CATALYST 2 Three way catalyst function P0420, P0430
EVAP SYSTEM 2 EVAP control system purge flow monitoring P0441
1 EVAP control system P0442
2 EVAP control system P0456
HO2S 2 Air fuel ratio (A/F) sensor 1 P1278, P1288
Air fuel ratio (A/F) sensor 1 P1279, P1289
Heated oxygen sensor 2 P0139, P0159
Heated oxygen sensor 2 P1146, P1166
Heated oxygen sensor 2 P1147, P1167
HO2S HTR 2 Air fuel ratio (A/F) sensor 1 heater P1031, P1032,
P1051, P1052
Heated oxygen sensor 2 heater P0037, P0038,
P0057, P0058
Self-diagnosis resultExample
DiagnosisIgnition cycle
← ON → OFF ← ON → OFF ← ON → OFF ← ON →
All OK Case 1 P0400 OK (1) — (1) OK (2) — (2)
P0402 OK (1) — (1) — (1) OK (2)
P1402 OK (1) OK (2) — (2) — (2)
SRT of EGR “CMPLT” “CMPLT” “CMPLT” “CMPLT”
Case 2 P0400 OK (1) — (1) — (1) — (1)
P0402 — (0) — (0) OK (1) — (1)
P1402 OK (1) OK (2) — (2) — (2)
SRT of EGR “INCMP” “INCMP” “CMPLT” “CMPLT”
NG exists Case 3 P0400 OK OK — —
P0402 — — — —
P1402 NG — NGNG
(Consecutive
NG)
(1st trip)
DTC1st trip DTC — 1st trip DTCDTC
(= MIL ON)
SRT of EGR “INCMP” “INCMP” “INCMP” “CMPLT”

EC-56Revision: October 2005
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
NG: Self-diagnosis is carried out and the result is NG.
—: Self-diagnosis is not carried out.
When all SRT related self-diagnoses showed OK results in a single cycle (Ignition OFF-ON-OFF), the SRT will
indicate “CMPLT”. → Case 1 above
When all SRT related self-diagnoses showed OK results through several different cycles, the SRT will indicate
“CMPLT” at the time the respective self-diagnoses have at least one OK result. → Case 2 above
If one or more SRT related self-diagnoses showed NG results in 2 consecutive cycles, the SRT will also indi-
cate “CMPLT”. → Case 3 above
The table above shows that the minimum number of cycles for setting SRT as “INCMP” is one (1) for each
self-diagnosis (Case 1 & 2) or two (2) for one of self-diagnoses (Case 3). However, in preparation for the state
emissions inspection, it is unnecessary for each self-diagnosis to be executed twice (Case 3) for the following
reasons:

The SRT will indicate “CMPLT” at the time the respective self-diagnoses have one (1) OK result.

The emissions inspection requires “CMPLT” of the SRT only with OK self-diagnosis results.

When, during SRT driving pattern, 1st trip DTC (NG) is detected prior to “CMPLT” of SRT, the self-diagno-
sis memory must be erased from ECM after repair.

If the 1st trip DTC is erased, all the SRT will indicate “INCMP”.
NOTE:
SRT can be set as “CMPLT” together with the DTC(s). Therefore, DTC check must always be carried out
prior to the state emission inspection even though the SRT indicates “CMPLT”.
SRT Service Procedure
If a vehicle has failed the state emissions inspection due to one or more SRT items indicating “INCMP”, review
the flowchart diagnostic sequence on the next page.

EC-58Revision: October 2005
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
NO TOOLS
A SRT code itself can not be displayed while only SRT status can be.
1. Turn ignition switch ON and wait 20 seconds.
2. SRT status is indicated as shown below.

When all SRT codes are set, MIL lights up continuously.

When any SRT codes are not set, MIL will flash periodically for 10 seconds.
How to Set SRT Code
To set all SRT codes, self-diagnosis for the items indicated above must be performed one or more times. Each
diagnosis may require a long period of actual driving under various conditions.
WITH CONSULT-II
Perform corresponding DTC Confirmation Procedure one by one based on Performance Priority in the table
on EC-55, "
SRT Item" .
WITHOUT CONSULT-II
The most efficient driving pattern in which SRT codes can be properly set is explained on the next page. The
driving pattern should be performed one or more times to set all SRT codes.
PBIB2317E

EC-72Revision: October 2005
BASIC SERVICE PROCEDURE
2005 QX56
BASIC SERVICE PROCEDUREPFP:00018
Basic InspectionUBS00KZU
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 GST.
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.
SEF 9 83 U
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SEF 9 77 U

BASIC SERVICE PROCEDURE
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DETAILED PROCEDURE
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.
–Head lamp 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 GST.
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.
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SEF 9 76 U
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