2006 INFINITI QX56 ESP

EC-16Revision: November 2009
PRECAUTIONS
2006 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.
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 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-68, "
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 negative battery cable.
SEF289H

EC-54Revision: November 2009
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2006 QX56
GST. The 1st trip freeze frame data can only be displayed on the CONSULT-II screen, not on the GST. For
details, see EC-118, "
Freeze Frame Data and 1st Trip Freeze Frame Data" .
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/MIL 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 stored 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 EC-61, "
HOW TO ERASE EMIS-
SION-RELATED DIAGNOSTIC INFORMATION" .
SYSTEM READINESS TEST (SRT) CODE
System Readiness Test (SRT) code is specified in Service $01 of SAE J1979.
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:
The SRT will also indicate “INCMP” if the self-diagnosis memory is erased for any reason or if the ECM mem-
ory power supply is interrupted for several hours.
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 ”.
PriorityItems
1 Freeze frame data Misfire
— DTC: P0300 - P0308
Fuel Injection System Function — DTC: P0171, P0172, P0174, P0175
2 Except the above items (Includes A/T related items)
3 1st trip freeze frame data
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

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-55
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
*: If completion of several SRTs is required, perform driving patterns (DTC confirmation procedure), one by one based on the pr iority 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.
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”.
HO2S 2 Air fuel ratio (A/F) sensor 1 P0133, P0153
Heated oxygen sensor 2 P0137, P0157
Heated oxygen sensor 2 P0138, P0158
Heated oxygen sensor 2 P0139, P0159
SRT item
(CONSULT-II indication) Performance
Priority* Required self-diagnostic items to set the SRT to “
CMPLT” Corresponding
DTC No.
Self-diagnosis result Example
Diagnosis Ignition 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 P0400OK (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 P0400OKOK ——
P0402 ——— —
P1402 NG—NG NG
(Consecutive
NG)
(1st trip) DTC 1st trip DTC
—1st trip DTC DTC
(= MIL ON)
SRT of EGR “INCMP ”“ INCMP”“ INCMP”“ CMPLT”

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-57
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
How to Display SRT Status
WITH CONSULT-II
Selecting “SRT STATUS” in “DTC CONFIRMATION ” mode with
CONSULT-II.
For items whose SRT codes are set, a “CMPLT ” is displayed on the
CONSULT-II screen; for items whose SRT codes are not set,
“INCMP ” is displayed.
A sample of CONSULT-II display for SRT code is shown in the fig-
ure.
“INCMP ” means the self-diagnosis is incomplete and SRT is not set.
“CMPLT ” means the self-diagnosis is complete and SRT is set.
NOTE:
Though displayed on the CONSULT-II screen, “HO2S HTR” is not
SRT item.
WITH GST
Selecting Service $01 with GST (Generic Scan Tool)
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-54, "
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.
SEF935Z
PBIB2317E

BASIC SERVICE PROCEDUREEC-71
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 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.
SEF983U
SEF976U
SEF977U

EC-80Revision: November 2009
BASIC SERVICE PROCEDURE
2006 QX56
11. Wait 20 seconds.
12. Rev up the engine two or three times and make sure that idle speed and ignition timing are within thespecifications.
13. If idle speed and ignition timing are not within the specification, Idle Air Volume Learning will not be carried out successfully. In this case, find the cause of the incident by referring to the DIAGNOSTIC PROCE-
DURE below.
DIAGNOSTIC PROCEDURE
If idle air volume learning cannot be performed successfully, proceed as follows:
1.Check that throttle valve is fully closed.
2. Check PCV valve operation.
3. Check that downstream of throttle valve is free from air leakage.
4. When the above three items check out OK, engine component parts and their installation condi-
tion are questionable. Check and eliminate the cause of the incident.
It is useful to perform EC-134, "
TROUBLE DIAGNOSIS - SPECIFICATION VALUE" .
5. If any of the following conditions occur after the engine has started, eliminate the cause of the
incident and perform Idle Air Volume Learning all over again:

Engine stalls.

Erroneous idle.
Fuel Pressure CheckUBS00L01
FUEL PRESSURE RELEASE
With CONSULT-II
1. Turn ignition switch ON.
2. Perform “FUEL PRESSURE RELEASE ” in “WORK SUPPORT ”
mode with CONSULT-II.
3. Start engine.
4. After engine stalls, crank it two or three times to release all fuel pressure.
5. Turn ignition switch OFF.
ITEM SPECIFICATION
Idle speed 650 ± 50 rpm (in P or N position)
Ignition timing 15 ± 5 ° BTDC (in P or N position)
SEC897C
SEF214Y

TROUBLE DIAGNOSISEC-83
C
DE
F
G H
I
J
K L
M A
EC
Revision: November 2009 2006 QX56
TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionUBS00L02
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 GST) or a circuit tester connected should
be performed. Follow the Work Flow on EC-84, "
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-88, "
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

EC-124Revision: November 2009
TROUBLE DIAGNOSIS
2006 QX56
*: Leaving cooling fan OFF with CONSULT-II while engine is running may cause the engine to overheat.
DTC & SRT CONFIRMATION MODE
SRT STATUS Mode
For details, refer to EC-54, "SYSTEM READINESS TEST (SRT) CODE" .
SRT WORK SUPPORT Mode
This mode enables a technician to drive a vehicle to set the SRT while monitoring the SRT status.
DTC WORK SUPPORT Mode
*: DTC P1442 and P1456 does not apply to JA60 models but appears in DTC Work Support Mode screens.FUEL/T TEMP
SEN

Change the fuel tank temperature using CONSULT-II.
VENT CON-
TROL/V

Ignition switch: ON
(Engine stopped)

Turn solenoid valve ON and OFF
with the CONSULT-II and listen
to operating sound. Solenoid valve makes an operating
sound.
Harness and connectors

Solenoid valve
TEST ITEM CONDITION JUDGEMENT CHECK ITEM (REMEDY)
Test mode
Test itemCorresponding DTC No. Reference page
EVAPORATIVE
SYSTEM PURG FLOW P0441
P0441EC-360
EVP SML LEAK P0442/P1442* P0442
EC-365P0455EC-419
EVP V/S LEAK P0456/P1456* P0456EC-427
PURG VOL CN/V P1444 P0443EC-373
A/F SEN1 A/F SEN1 (B1) P1276
P0130EC-213A/F SEN1 (B1) P1278/P1279 P0133EC-241
A/F SEN1 (B2) P1286 P0150EC-213
A/F SEN1 (B2) P1288/P1289 P0153EC-241
HO2S2 HO2S2 (B1) P0139
P0139EC-277
HO2S2 (B1) P1146 P0138EC-264
HO2S2 (B1) P1147 P0137EC-253
HO2S2 (B2) P0159 P0159EC-277
HO2S2 (B2) P1166 P0158EC-264
HO2S2 (B2) P1167 P0157EC-253