ignition INFINITI QX56 2007 Factory Service Manual

ON BOARD DIAGNOSTIC (OBD) SYSTEM
EC-55
< SERVICE INFORMATION >
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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.

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

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

EC-64
< SERVICE INFORMATION >
ON BOARD DIAGNOSTIC (OBD) SYSTEM
When any SRT codes are not set, MIL may flash without DTC. For the details, refer to EC-49, "Emission-
related Diagnostic Information".
HOW TO SWITCH DIAGNOSTIC TEST MODE
NOTE:
•It is better to count the time accurately with a clock.
•It is impossible to switch the diagnostic mode when an accelerator pedal position sensor circuit has
a malfunction.
•Always ECM returns to Diagnostic Test Mode I after ignition switch is turned OFF.
How to Set Diagnostic Test Mode II (Self-diagnostic Results)
1. Confirm that accelerator pedal is fully released, turn ignition switch ON and wait 3 seconds.
2. Repeat the following procedure quickly five times within 5 seconds.
a. Fully depress the accelerator pedal.
b. Fully release the accelerator pedal.
3. Wait 7 seconds, fully depress the accelerator pedal and keep it for approx. 10 seconds until the MIL starts
blinking.
NOTE:
Do not release the accelerator pedal for 10 seconds if MIL may start blinking on the halfway of this
10 seconds. This blinking is displaying SRT status and is continued for another 10 seconds. For
the details, refer to EC-49, "
Emission-related Diagnostic Information".
4. Fully release the accelerator pedal.
ECM has entered to Diagnostic Test Mode II (Self-diagnostic results).
NOTE:
Wait until the same DTC (or 1st trip DTC) appears to confirm all DTCs certainly.
How to Erase Diagnostic Test Mode II (Self-diagnostic Results)
1. Set ECM in Diagnostic Test Mode II (Self-diagnostic results). Refer to "How to Set Diagnostic Test Mode II
(Self-diagnostic Results)".
2. Fully depress the accelerator pedal and keep it for more than 10 seconds.
The emission-related diagnostic information has been erased from the backup memory in the ECM.
3. Fully release the accelerator pedal, and confirm the DTC 0000 is displayed.
DIAGNOSTIC TEST MODE I — BULB CHECK
In this mode, the MIL on the instrument panel should stay ON. If it remains OFF, check the bulb. Refer to DI-26
or see EC-643.
DIAGNOSTIC TEST MODE I — MALFUNCTION WARNING
This DTC number is clarified in Diagnostic Test Mode II (SELF-DIAGNOSTIC RESULTS)
DIAGNOSTIC TEST MODE II — SELF-DIAGNOSTIC RESULTS
In this mode, the DTC and 1st trip DTC are indicated by the number of blinks of the MIL as shown below.
The DTC and 1st trip DTC are displayed at the same time. If the MIL does not illuminate in diagnostic test
mode I (Malfunction warning), all displayed items are 1st trip DTCs. If only one code is displayed when the MIL
illuminates in diagnostic test mode II (SELF-DIAGNOSTIC RESULTS), it is a DTC; if two or more codes are
PBIB0092E
MIL Condition
ON When the malfunction is detected.
OFF No malfunction.

EC-72
< SERVICE INFORMATION >
BASIC SERVICE PROCEDURE
2. Rev engine (2,000 to 3,000 rpm) two or three times under no
load, then run engine at idle speed for about 1 minute.
3. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-75, "
Idle Speed and Ignition Timing Check" .
Without CONSULT-II
1. Run engine at about 2,000 rpm for about 2 minutes under no load.
2. Rev engine (2,000 to 3,000 rpm) two or three times under no load, then run engine at idle speed for about
1 minute.
3. Check idle speed.
Refer to EC-75, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 4.
4.PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-77, "
Accelerator Pedal Released Position Learning" .
>> GO TO 5.
5.PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-77, "
Throttle Valve Closed Position Learning" .
>> GO TO 6.
6.PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-78, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Ye s > > G O T O 7 .
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
7.CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
PBIA8513J
650 ± 50 rpm (in P or N position)
SEF058Y
650 ± 50 rpm (in P or N position)

BASIC SERVICE PROCEDURE
EC-73
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1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-75, "
Idle Speed and Ignition Timing Check" .
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-75, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 10.
NG >> GO TO 8.
8.DETECT MALFUNCTIONING PART
Check the following.
• Check camshaft position sensor (PHASE) and circuit. Refer to EC-342
.
• Check crankshaft position sensor (POS) and circuit. Refer to EC-336
.
OK or NG
OK >> GO TO 9.
NG >> 1. Repair or replace.
2. GO TO 4.
9.CHECK ECM FUNCTION
1. Substitute another known-good ECM to check ECM function. (ECM may be the cause of an incident, but
this is a rare case.)
2. Perform initialization of IVIS (NATS) system and registration of all IVIS (NATS) ignition key IDs. Refer to
BL-117, "
ECM Re-communicating Function".
>> GO TO 4.
10.CHECK IGNITION TIMING
1. Run engine at idle.
2. Check ignition timing with a timing light.
Refer to EC-75, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 19.
NG >> GO TO 11.
11 .PERFORM ACCELERATOR PEDAL RELEASED POSITION LEARNING
1. Stop engine.
2. Perform EC-77, "
Accelerator Pedal Released Position Learning" .
>> GO TO 12.
12.PERFORM THROTTLE VALVE CLOSED POSITION LEARNING
Perform EC-77, "
Throttle Valve Closed Position Learning" .
>> GO TO 13. 650 ± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)
15 ± 5° BTDC (in P or N position)
BBIA0379E

EC-74
< SERVICE INFORMATION >
BASIC SERVICE PROCEDURE
13.PERFORM IDLE AIR VOLUME LEARNING
Refer to EC-78, "
Idle Air Volume Learning" .
Is Idle Air Volume Learning carried out successfully?
Ye s o r N o
Yes >> GO TO 14.
No >> 1. Follow the instruction of Idle Air Volume Learning.
2. GO TO 4.
14.CHECK TARGET IDLE SPEED AGAIN
With CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Read idle speed in “DATA MONITOR” mode with CONSULT-II.
Refer to EC-75, "
Idle Speed and Ignition Timing Check" .
Without CONSULT-II
1. Start engine and warm it up to normal operating temperature.
2. Check idle speed.
Refer to EC-75, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 15.
NG >> GO TO 17.
15.CHECK IGNITION TIMING AGAIN
1. Run engine at idle.
2. Check ignition timing with a timing light.
Refer to EC-75, "
Idle Speed and Ignition Timing Check" .
OK or NG
OK >> GO TO 19.
NG >> GO TO 16.
16.CHECK TIMING CHAIN INSTALLATION
Check timing chain installation. Refer to EM-38
.
OK or NG
OK >> GO TO 17.
NG >> 1. Repair the timing chain installation.
2. GO TO 4.
17.DETECT MALFUNCTIONING PART
Check the following.
• Check camshaft position sensor (PHASE) and circuit. Refer to EC-342
.
• Check crankshaft position sensor (POS) and circuit. Refer to EC-336
.
OK or NG
OK >> GO TO 18.
NG >> 1. Repair or replace.
2. GO TO 4.
18.CHECK ECM FUNCTION 650 ± 50 rpm (in P or N position)
650 ± 50 rpm (in P or N position)
15 ± 5° BTDC (in P or N position)
BBIA0379E