2004 INFINITI QX56 sensor

ON BOARD DIAGNOSTIC (OBD) SYSTEM
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Revision: August 20072004 QX56CYL 3 MISFIRE P0303 0303 — —×EC-243
CYL 4 MISFIRE P0304 0304 — —×EC-243
CYL 5 MISFIRE P0305 0305 — —×EC-243
CYL 6 MISFIRE P0306 0306 — —×EC-243
CYL 7 MISFIRE P0307 0307 — —×EC-243
CYL 8 MISFIRE P0308 0308 — —×EC-243
KNOCK SEN/CIRC-B1 P0327 0327 — —×EC-250
KNOCK SEN/CIRC-B1 P0328 0328 — —×EC-250
KNOCK SEN/CIRC-B2 P0332 0332 — —×EC-250
KNOCK SEN/CIRC-B2 P0333 0333 — —×EC-250
CKP SEN/CIRCUIT P0335 0335 — —×EC-255
CMP SEN/CIRC-B1 P0340 0340 — —×EC-261
TW CATALYST SYS-B1 P0420 0420×××EC-267
TW CATALYST SYS-B2 P0430 0430×××EC-267
EVAP PURG FLOW/MON P0441 0441×××EC-271
EVAP SMALL LEAK P0442 0442×××EC-276
PURG VOLUME CONT/V P0444 0444 — —×EC-285
PURG VOLUME CONT/V P0445 0445 — —×EC-285
VENT CONTROL VALVE P0447 0447 — —×EC-292
EVAP SYS PRES SEN P0451 0451 — —×EC-299
EVAP SYS PRES SEN P0452 0452 — —×EC-302
EVAP SYS PRES SEN P0453 0453 — —×EC-308
EVAP GROSS LEAK P0455 0455 —××EC-316
EVAP VERY SML LEAK P0456 0456
×*6××EC-324
FUEL LEV SEN SLOSH P0460 0460 — —×EC-334
FUEL LEVEL SENSOR P0461 0461 — —×EC-336
FUEL LEVL SEN/CIRC P0462 0462 — —×EC-338
FUEL LEVL SEN/CIRC P0463 0463 — —×EC-338
VEH SPEED SEN/CIRC*4P0500 0500 — —×EC-340
ISC SYSTEM P0506 0506 — —×EC-342
ISC SYSTEM P0507 0507 — —×EC-344
PW ST P SEN/CIRC P0550 0550 — —×EC-346
ECM P0605 0605 — —× or —EC-351
TCM P0700 0700 — — —AT- 1 0 8
PNP SW/CIRC P0705 0705 — —×AT- 1 0 9
ATF TEMP SEN/CIRC P0710 0710 — —×AT- 1 3 1
VEH SPD SEN/CIR AT*4P0720 0720 — —×AT- 11 2
TCC SOLENOID/CIRC P0740 0740 — —×AT- 11 8
A/T TCC S/V FNCTN P0744 0744 — —×AT- 1 2 1
L/PRESS SOL/CIRC P0745 0745 — —×AT- 1 2 4
A/F SEN1 HTR (B1) P1031 1031×××EC-354
A/F SEN1 HTR (B1) P1032 1032×××EC-354
Items
(CONSULT-II screen terms)DTC*
1
SRT codeTest value/
Test limit
(GST only)1st trip DTCReference
page CONSULT-II
GST*
2ECM*3

EC-52Revision: August 2007
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2004 QX56
A/F SEN1 HTR (B2) P1051 1051×××EC-354
A/F SEN1 HTR (B2) P1052 1052×××EC-354
ECM BACK UP/CIRC P1065 1065 — —×EC-361
ETC ACTR P1121 1121 — — —EC-365
ETC FUNCTION/CIRC P1122 1122 — — —EC-367
E T C M O T P W R P 11 2 4 11 2 4 — — —EC-373
E T C M O T P W R P 11 2 6 11 2 6 — — —EC-373
E T C M O T P 11 2 8 11 2 8 — — —EC-378
HO2S2 (B1) P1146 1146×××EC-383
HO2S2 (B1) P1147 1147×××EC-395
CLOSED LOOP-B1 P1148 1148 — — —EC-407
HO2S2 (B2) P1166 1166×××EC-383
HO2S2 (B2) P1167 1167×××EC-395
CLOSED LOOP-B2 P1168 1168 — — —EC-407
TCS C/U FUNCTN P1211 1211 — —×EC-408
TCS/CIRC P1212 1212 — —×EC-409
ENG OVER TEMP P1217 1217 — — —EC-410
CTP LEARNING P1225 1225 — —×EC-420
CTP LEARNING P1226 1226 — —×EC-422
SENSOR POWER/CIRC P1229 1229 — — —EC-424
A/F SENSOR1 (B1) P1271 1271 — —×EC-429
A/F SENSOR1 (B1) P1272 1272 — —×EC-437
A/F SENSOR1 (B1) P1273 1273 — —×EC-445
A/F SENSOR1 (B1) P1274 1274 — —×EC-454
A/F SENSOR1 (B1) P1276 1276 — —×EC-463
A/F SENSOR1 (B1) P1278 1278×××EC-472
A/F SENSOR1 (B1) P1279 1279×××EC-484
A/F SENSOR1 (B2) P1281 1281 — —×EC-429
A/F SENSOR1 (B2) P1282 1282 — —×EC-437
A/F SENSOR1 (B2) P1283 1283 — —×EC-445
A/F SENSOR1 (B2) P1284 1284 — —× EC-454
A/F SENSOR1 (B2) P1286 1286 — —×EC-463
A/F SENSOR1 (B2) P1288 1288×××EC-472
A/F SENSOR1 (B2) P1289 1289×××EC-484
PURG VOLUME CONT/V P1444 1444 — —×EC-496
VENT CONTROL VALVE P1446 1446 — —×EC-504
ASCD SW P1564 1564 — — —EC-510,
EC-517
ACC COMMAND VALUE*8P1568 1568 — — —EC-524
ASCD BRAKE SW P1572 1572 — — —EC-525,
EC-534
ASCD VHL SPD SEN*7P1574 1574 — — —EC-542,
EC-534
Items
(CONSULT-II screen terms)DTC*
1
SRT codeTest value/
Test limit
(GST only)1st trip DTCReference
page CONSULT-II
GST*
2ECM*3

ON BOARD DIAGNOSTIC (OBD) SYSTEM
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Revision: August 20072004 QX56
*1: 1st trip DTC No. is the same as DTC No.
*2: This number is prescribed by SAE J2012.
*3: In Diagnostic Test Mode II (Self-diagnostic results). This number is controlled by NISSAN.
*4: When the fail-safe operations for both self-diagnoses occur at the same time, the MIL illuminates.
*5: The trouble shooting for this DTC needs CONSULT-II.
*6: SRT code will not be set if the self-diagnostic result is NG.
*7: 2WD models
*8: Models with ICC system
DTC AND 1ST TRIP DTC
The 1st trip DTC (whose number is the same as the DTC number) is displayed for the latest self-diagnostic
result obtained. If the ECM memory was cleared previously, and the 1st trip DTC did not reoccur, the 1st trip
DTC will not be displayed.
If a malfunction is detected during the 1st trip, the 1st trip DTC is stored in the ECM memory. The MIL will not
light up (two trip detection logic). If the same malfunction is not detected in the 2nd trip (meeting the required
driving pattern), the 1st trip DTC is cleared from the ECM memory. If the same malfunction is detected in the
2nd trip, both the 1st trip DTC and DTC are stored in the ECM memory and the MIL lights up. In other words,
the DTC is stored in the ECM memory and the MIL lights up when the same malfunction occurs in two consec-
utive trips. If a 1st trip DTC is stored and a non-diagnostic operation is performed between the 1st and 2nd
trips, only the 1st trip DTC will continue to be stored. For malfunctions that blink or light up the MIL during the
1st trip, the DTC and 1st trip DTC are stored in the ECM memory.
Procedures for clearing the DTC and the 1st trip DTC from the ECM memory are described in EC-62, "
HOW
TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION" .
For malfunctions in which 1st trip DTCs are displayed, refer to EC-50, "
EMISSION-RELATED DIAGNOSTIC
INFORMATION ITEMS" . These items are required by legal regulations to continuously monitor the system/
component. In addition, the items monitored non-continuously are also displayed on CONSULT-II.
NATS MALFUNCTIONP1610 -
P16151610 - 1615 — —×BL-138
P-N POS SW/CIRCUIT P1706 1706 — —×EC-546
TURBINE REV S/CIRC P1716 1716 — —×AT- 1 3 4
A/T INTERLOCK P1730 1730 — — —AT- 1 3 9
I/C SOLENOID/CIRC P1752 1752 — — —AT- 1 4 5
I/C SOLENOID FNCTN P1754 1754 — — —AT- 1 4 8
FR/B SOLENOID/CIRC P1757 1757 — — —AT- 1 5 1
FR/B SOLENOID/CIRC P1759 1759 — — —AT- 1 5 4
D/C SOLENOID/CIRC P1762 1762 — — —AT- 1 5 7
D/C SOLENOID FNCTN P1764 1764 — — —AT- 1 6 0
HLR/C SOL/CIRC P1767 1767 — — —AT- 1 6 3
HLR/C SOL FNCTN P1769 1769 — — —AT- 1 6 6
LC/B SOLENOID/CIRC P1772 1772 — — —AT- 1 6 9
LC/B SOLENOID FNCT P1774 1774 — — —AT- 1 7 2
BRAKE SW/CIRCUIT P1805 1805 — —×EC-551
APP SEN 1/CIRC P2122 2122 — — —EC-556
APP SEN 1/CIRC P2123 2123 — — —EC-556
APP SEN 2/CIRC P2127 2127 — — —EC-562
APP SEN 2/CIRC P2128 2128 — — —EC-562
TP SENSOR P2135 2135 — — —EC-569
APP SENSOR P2138 2138 — — —EC-576
Items
(CONSULT-II screen terms)DTC*
1
SRT codeTest value/
Test limit
(GST only)1st trip DTCReference
page CONSULT-II
GST*
2ECM*3

ON BOARD DIAGNOSTIC (OBD) SYSTEM
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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-62, "
HOW TO ERASE EMIS-
SION-RELATED DIAGNOSTIC INFORMATION" .
SYSTEM READINESS TEST (SRT) CODE
System Readiness Test (SRT) code is specified in Mode 1 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”.
Priority Items
1Freeze 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
Item
(CONSULT-II indication)Performance
Priority*1Required self-diagnostic items to set the SRT to “CMPLT”Corresponding DTC
No.
CATALYST 2 Three way catalyst function P0420, P0430
EVAPORATIVE
SYSTEM2 EVAP control system purge flow monitoring P0441
1 EVAP control system P0442
2 EVAP control system P0456
HO2S 2 A/F sensor 1 P1278, P1288
A/F sensor 1 P1279, P1289
Heated oxygen sensor 2 P0139, P0159
Heated oxygen sensor 2 P1146, P1166
Heated oxygen sensor 2 P1147, P1167

EC-56Revision: August 2007
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2004 QX56
*1: If completion of several SRTs is required, perform driving patterns (DTC confirmation procedure), one by one based on the pri ority 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”.
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”.
HO2S HTR 2 A/F sensor 1 heater P1031, P1032,
P1051, P1052
Heated oxygen sensor 2 heater P0037, P0038,
P0057, P0058 Item
(CONSULT-II indication)Performance
Priority
*1Required self-diagnostic items to set the SRT to “CMPLT”Corresponding DTC
No.
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”

ON BOARD DIAGNOSTIC (OBD) SYSTEM
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EVAPORA-
TIVE
SYSTEMEVAP control system (Small leak) P0442 05H 03H Max.
1/128mm2
EVAP control system purge flow monitoring P0441 06H 83H Min. 20mV
EVAP control system (Very small leak) P0456 07H 03H Max.
1/128mm
2
HO2SA/F sensor 1 (Bank 1)P1271 41H 8EH Min. 5 mV
P1272 42H 0EH Max. 5 mV
P1273 43H 0EH Max. 0.002
P1274 44H 8EH Min. 0.002
P1278 45H 8EH Min. 0.004
P1276 46H 0EH Max. 5 mV
P1276 47H 8EH Min. 5 mV
P1279 48H 8EH Min. 0.004
A/F sensor 1 (Bank 2)P1281 4CH 8FH Min. 5 mV
P1282 4DH 0FH Max. 5 mV
P1283 4EH 0FH Max. 0.002
P1284 4FH 8FH Min. 0.002
P1288 50H 8FH Min. 0.004
P1286 51H 0FH Max. 5 mV
P1286 52H 8FH Min. 5 mV
P1289 53H 8FH Min. 0.004
Heated oxygen sensor 2 (Bank 1)P0139 19H 86H Min. 10mV/500ms
P1147 1AH 86H Min. 10mV
P1146 1BH 06H Max. 10mV
P0138 1CH 06H Max. 10mV
Heated oxygen sensor 2 (Bank 2)P0159 21H 87H Min. 10mV/500ms
P1167 22H 87H Min. 10mV
P1166 23H 07H Max. 10mV
P0158 24H 07H Max. 10mV
HO2S HTRA/F sensor 1 heater (Bank 1)P1032 57H 10H Max. 5 mV
P1031 58H 90H Min. 5 mV
A/F sensor 1 heater (Bank 2)P1052 59H 11H Max. 5 mV
P1051 5AH 91H Min. 5 mV
Heated oxygen sensor 2 heater (Bank 1)P0038 2DH 0AH Max. 20mV
P0037 2EH 8AH Min. 20mV
Heated oxygen sensor 2 heater (Bank 2)P0058 2FH 0BH Max. 20mV
P0057 30H 8BH Min. 20mV SRT item Self-diagnostic test item DTCTest value (GST display)
Test limit Conversion
TID CID

EC-64Revision: August 2007
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2004 QX56
When there is an open circuit on MIL circuit, the ECM cannot warn the driver by lighting MIL up 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.
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.
4. Fully release the accelerator pedal.
Diagnostic Test
ModeKEY and ENG.
Statu sFunction 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
detected twice in two consecutive driving cycles (two trip
detection 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

TROUBLE DIAGNOSIS
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TROUBLE DIAGNOSISPFP:00004
Trouble Diagnosis IntroductionUBS00GZW
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 EC-72, "
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-75
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
SEF 2 33 G
SEF 2 34 G