2007 INFINITI QX56 DTC

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-55
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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”.
*: 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.
NG: Self-diagnosis is carried out and the result is NG.
—: Self-diagnosis is not carried out.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 P0133, P0153
Heated oxygen sensor 2 P0137, P0157
Heated oxygen sensor 2 P0138, P0158
Heated oxygen sensor 2 P0139, P0159
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-56
< SERVICE INFORMATION >
ON BOARD DIAGNOSTIC (OBD) SYSTEM
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-diagnosis
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.

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-57
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P O 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)
*1 "How to Read DTC and 1st Trip DTC" *2 "How to Display SRT Status" *3 "How to Set SRT Code"
PBIB2320E
SEF935Z

EC-58
< SERVICE INFORMATION >
ON BOARD DIAGNOSTIC (OBD) SYSTEM
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 "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-60
< SERVICE INFORMATION >
ON BOARD DIAGNOSTIC (OBD) SYSTEM
• Sea level
• Flat road
• Ambient air temperature: 20 - 30°C (68 - 86°F)
• Diagnosis is performed as quickly as possible under normal conditions.
Under different conditions [For example: ambient air temperature other than 20 - 30°C (68 - 86°F)], diagno-
sis may also be performed.
Pattern 1:
•The engine is started at the engine coolant temperature of −10 to 35°C (14 to 95°F)
(where the voltage between the ECM terminal 73 and ground is 3.0 - 4.3V).
•The engine must be operated at idle speed until the engine coolant temperature is greater than 70°C
(158°F) (where the voltage between the ECM terminal 73 and ground is lower than 1.4V).
•The engine is started at the fuel tank temperature of warmer than 0°C (32°F) (where the voltage
between the ECM terminal 107 and ground is less than 4.1V).
Pattern 2:
• When steady-state driving is performed again even after it is interrupted, each diagnosis can be conducted.
In this case, the time required for diagnosis may be extended.
Pattern 3:
• Operate vehicle following the driving pattern shown in the figure.
• Release the accelerator pedal during decelerating vehicle speed
from 90 km/h (56 MPH) to 0 km/h (0 MPH).
Pattern 4:
• The accelerator pedal must be held very steady during steady-
state driving.
• If the accelerator pedal is moved, the test must be conducted all
over again.
*1: Depress the accelerator pedal until vehicle speed is 90 km/h (56
MPH), then release the accelerator pedal and keep it released for
more than 10 seconds. Depress the accelerator pedal until vehicle
speed is 90 km/h (56 MPH) again.
*2: Checking the vehicle speed with GST is advised.
Suggested Transmission Gear Position
Set the selector lever in the D position with the overdrive switch turned ON.
TEST VALUE AND TEST LIMIT (GST ONLY — NOT APPLICABLE TO CONSULT-II)
The following is the information specified in Service $06 of SAE J1979.
The test value is a parameter used to determine whether a system/circuit diagnostic test is OK or NG while
being monitored by the ECM during self-diagnosis. The test limit is a reference value which is specified as the
maximum or minimum value and is compared with the test value being monitored.
These data (test value and test limit) are specified by Test ID (TID) and Component ID (CID) and can be dis-
played on the GST screen.
PBIB2244E
Item Self-diagnostic test item DTCTest value (GST display)
Test limit Conversion
TID CID
CATALYSTThree way catalyst function (Bank 1)P0420 01H 01H Max. 1/128
P0420 02H 81H Min. 1
Three way catalyst function (Bank 2)P0430 03H 02H Max. 1/128
P0430 04H 82H Min. 1
EVAP
SYSTEMEVAP control system (Small leak) P0442 05H 03H Max.
1/128 mm
2
EVAP control system purge flow monitoring P0441 06H 83H Min. 20 mV
EVAP control system (Very small leak) P0456 07H 03H Max.
1/128 mm
2

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-61
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HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION
How to Erase DTC
WITH CONSULT-II
The emission related diagnostic information in the ECM can be erased by selecting “ERASE” in the “SELF-
DIAG RESULTS” mode with CONSULT-II.
If DTCs are displayed for both ECM and TCM (Transmission control module), they need to be erased individu-
ally from the ECM and TCM (Transmission control module).
NOTE:
If the DTC is not for A/T related items (see EC-9
), skip steps 2 through 4.
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.
2. Turn CONSULT-II ON and touch “A/T”.
3. Touch “SELF-DIAG RESULTS”.
HO2SAir fuel ratio (A/F) sensor 1 (Bank 1)P0131 41H 8EH Min. 5mV
P0132 42H 0EH Max. 5mV
P2A00 43H 0EH Max. 0.002
P2A00 44H 8EH Min. 0.002
P0133 45H 8EH Min. 0.002
P0130 46H 0EH Max. 5mV
P0130 47H 8EH Min. 5mV
P0133 48H 8EH Min. 0.002
Air fuel ratio (A/F) sensor 1 (Bank 2)P0151 4CH 8FH Min. 5mV
P0152 4DH 0FH Max. 5mV
P2A03 4EH 0FH Max. 0.002
P2A03 4FH 8FH Min. 0.002
P0153 50H 8FH Min. 0.002
P0150 51H 0FH Max. 5mV
P0150 52H 8FH Min. 5mV
P0153 53H 8FH Min. 0.002
Heated oxygen sensor 2 (Bank 1)P0139 19H 86H Min. 10mV/500 ms
P0137 1AH 86H Min. 10 mV
P0138 1BH 06H Max. 10 mV
P0138 1CH 06H Max. 10mV
Heated oxygen sensor 2 (Bank 2)P0159 21H 87H Min. 10 mV/500 ms
P0157 22H 87H Min. 10 mV
P0158 23H 07H Max. 10 mV
P0158 24H 07H Max. 10mV
HO2S
HTRA/F sensor 1 heater (Bank 1) P0032 57H 10H Max. 5 mV
P0031 58H 90H Min. 5 mV
A/F sensor 1 heater (Bank 2)P0052 59H 11H Max. 5 mV
P0051 5AH 91H Min. 5 mV
Heated oxygen sensor 2 heater (Bank 1)P0038 2DH 0AH Max. 20 mV
P0037 2EH 8AH Min. 20 mV
Heated oxygen sensor 2 heater (Bank 2)P0058 2FH 0BH Max. 20 mV
P0057 30H 8BH Min. 20 mV Item Self-diagnostic test item DTCTest value (GST display)
Test limit Conversion
TID CID

EC-62
< SERVICE INFORMATION >
ON BOARD DIAGNOSTIC (OBD) SYSTEM
4. Touch “ERASE”. [The DTC in the TCM (Transmission control module) will be erased.] Then touch “BACK”
twice.
5. Touch “ENGINE”.
6. Touch “SELF-DIAG RESULTS”.
7. Touch “ERASE”. (The DTC in the ECM will be erased.)
WITH GST
The emission related diagnostic information in the ECM can be erased by selecting Service $04 with GST.
NOTE:
If the DTC is not for A/T related items (see EC-9
), skip step 2.
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.
2. Perform AT-39, "
OBD-II Diagnostic Trouble Code (DTC)". (The DTC in TCM will be erased)
3. Select Service $04 with GST (Generic Scan Tool).
No Tools
NOTE:
If the DTC is not for AT related items (see EC-9
), skip step 2.
1. If the ignition switch stays ON after repair work, be sure to turn ignition switch OFF once.
Wait at least 10 seconds and then turn it ON (engine stopped) again.
2. Perform AT-39, "
OBD-II Diagnostic Trouble Code (DTC)". (The DTC in the TCM will be erased.)
3. Change the diagnostic test mode from Mode II to Mode I by depressing the accelerator pedal. Refer to
EC-63, "
Malfunction Indicator Lamp (MIL)".
•If the battery is disconnected, the emission-related diagnostic information will be lost within 24
hours.
•The following data are cleared when the ECM memory is erased.
- Diagnostic trouble codes
- 1st trip diagnostic trouble codes
- Freeze frame data
- 1st trip freeze frame data
- System readiness test (SRT) codes
- Test values
SCIA5671E

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-63
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Actual work procedures are explained using a DTC as an example. Be careful so that not only the DTC, but all
of the data listed above, are cleared from the ECM memory during work procedures.
Malfunction Indicator Lamp (MIL)INFOID:0000000003531607
DESCRIPTION
The MIL is located on the instrument panel.
1. The MIL will light up when the ignition switch is turned ON with-
out the engine running. This is a bulb check.
If the MIL does not light up, refer to DI-26
or see EC-643.
2. When the engine is started, the MIL should go off.
If the MIL remains on, the on board diagnostic system has
detected an engine system malfunction.
ON BOARD DIAGNOSTIC SYSTEM FUNCTION
The on board diagnostic system has the following three functions.
When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting up MIL when there is
malfunction on engine control system.
Therefore, when electrical controlled throttle and part of ECM related diagnoses are continuously detected as
NG for 5 trips, ECM warns the driver that engine control system malfunctions and MIL circuit is open by means
of operating fail-safe function.
The fail-safe function also operates when above diagnoses except MIL circuit are detected and demands the
driver to repair the malfunction.
MIL Flashing Without DTC
SEF217U
Diagnostic Test
ModeKEY and ENG.
Sta tusFunction Explanation of Function
Mode I Ignition switch in
ON position
Engine stoppedBULB CHECK This function checks the MIL bulb for damage (blown, open
circuit, etc.).
If the MIL does not come on, check MIL circuit.
Engine running MALFUNCTION
WARNINGThis is a usual driving condition. When a malfunction is de-
tected twice in two consecutive driving cycles (two trip de-
tection logic), the MIL will light up to inform the driver that a
malfunction has been detected.
The following malfunctions will light up or blink the MIL in
the 1st trip.
• Misfire (Possible three way catalyst damage)
• One trip detection diagnoses
Mode II Ignition switch in
ON position
Engine stoppedSELF-DIAGNOSTIC
RESULTSThis function allows DTCs and 1st trip DTCs to be read.
Engine operating condition in fail-safe mode Engine speed will not rise more than 2,500 rpm due to the fuel cut