2009 INFINITI QX56 ESP

EC-44
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
*: 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-III.
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. T he 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 se lf-diagnoses have at least one OK result. → Case 2 above
If one or more SRT related self-diagnoses showed NG resu lts in 2 consecutive cycles, the SRT will also indi-
cate “CMPLT”. → Case 3 above
The table above shows that the minimum number of cycl es for setting SRT as “INCMP” is one (1) for each
self-diagnosis (Case 1 & 2) or two (2) for one of self-di agnoses (Case 3). However, in preparation for the state
emissions inspection, it is unnecessary for each self-d iagnosis 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.
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
SRT item
(CONSULT-III 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 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 — NG NG
(Consecutive NG)
(1st trip) DTC 1st trip DTC — 1st trip DTC DTC
(= MIL ON)
SRT of EGR “INCMP” “INCMP” “INCMP” “CMPLT”
Revision: December 20092009 QX56

EC-46
< FUNCTION DIAGNOSIS >[VK56DE]
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 i ndicated above must be performed one or more times. Each
diagnosis may require a long period of actual driving under various conditions.
WITH CONSULT-III
Perform corresponding DTC Confirmation Procedure one by one based on Performance Priority in the table
on "SRT Item".
WITHOUT CONSULT-III
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
Revision: December 20092009 QX56

ON BOARD DIAGNOSTIC (OBD) SYSTEMEC-49
< FUNCTION DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
Item
OBD-
MID Self-diagnostic test item DTC Test value and Test
limit
(GST display) Description
TID Unit and
Scaling ID
HO2S 01H
Air fuel ratio (A/F) sensor 1
(Bank 1) P0131 83H 0BH
Minimum sensor output voltage for test
cycle
P0131 84H 0BH Maximum sensor output voltage for test
cycle
P0130 85H 0BH Minimum sensor output voltage for test
cycle
P0130 86H 0BH Maximum sensor output voltage for test
cycle
P0133 87H 04H Response rate: Response ratio (Lean to
Rich)
P0133 88H 04H Response rate: Response ratio (Rich to
Lean)
P2A00 89H 84H The amount of shift in air fuel ratio
P2A00 8AH 84H The amount of shift in air fuel ratio P0130 8BH 0BH Difference in sensor output voltage
P0133 8CH 83H Response gain at the limited frequency
02H Heated oxygen sensor 2
(Bank 1) P0138 07H 0CH
Minimum sensor output voltage for test
cycle
P0137 08H 0CH Maximum sensor output voltage for test
cycle
P0138 80H 0CH Sensor output voltage
P0139 81H 0CH Difference in sensor output voltage
03H Heated oxygen sensor 3
(Bank 1) P0143 07H 0CH
Minimum sensor output voltage for test
cycle
P0144 08H 0CH Maximum sensor output voltage for test
cycle
P0146 80H 0CH Sensor output voltage
P0145 81H 0CH Difference in sensor output voltage
Revision: December 20092009 QX56

EC-50
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
HO2S05H
Air fuel ratio (A/F) sensor 1
(Bank 2) P0151 83H 0BH
Minimum sensor output voltage for test
cycle
P0151 84H 0BH Maximum sensor output voltage for test
cycle
P0150 85H 0BH Minimum sensor output voltage for test
cycle
P0150 86H 0BH Maximum sensor output voltage for test
cycle
P0153 87H 04H Response rate: Response ratio (Lean to
Rich)
P0153 88H 04H Response rate: Response ratio (Rich to
Lean)
P2A03 89H 84H The amount of shift in air fuel ratio
P2A03 8AH 84H The amount of shift in air fuel ratio P0150 8BH 0BH Difference in sensor output voltage
P0153 8CH 83H Response gain at the limited frequency
06H Heated oxygen sensor 2
(Bank 2) P0158 07H 0CH
Minimum sensor output voltage for test
cycle
P0157 08H 0CH Maximum sensor output voltage for test
cycle
P0158 80H 0CH Sensor output voltage
P0159 81H 0CH Difference in sensor output voltage
07H Heated oxygen sensor 3
(Bank2) P0163 07H 0CH
Minimum sensor output voltage for test
cycle
P0164 08H 0CH Maximum sensor output voltage for test
cycle
P0166 80H 0CH Sensor output voltage
P0165 81H 0CH Difference in sensor output voltage
CATA-
LYST 21H
Three way catalyst function
(Bank1) P0420 80H 01H O2 storage index
P0420 82H 01H
Switching time lag engine exhaust index
value
P2423 83H 0CH Difference in 3rd O2 sensor output volt-
age
P2423 84H 84H O2 storage index in HC trap catalyst
22H Three way catalyst function
(Bank2) P0430 80H 01H O2 storage index
P0430 82H 01H
Switching time lag engine exhaust index
value
P2424 83H 0CH Difference in 3rd O2 sensor output volt-
age
P2424 84H 84H O2 storage index in HC trap catalyst
Item
OBD-
MID Self-diagnostic test item DTC Test value and Test
limit
(GST display) Description
TID Unit and
Scaling ID
Revision: December 20092009 QX56

EC-72
< FUNCTION DIAGNOSIS >[VK56DE]
ON BOARD DIAGNOSTIC (OBD) SYSTEM
*: DTC P1442 and P1456 does not apply to JA60 models but appears in DTC Work Support Mode screens.
Generic Scan Tool (GST) FunctionINFOID:0000000003771319
DESCRIPTION
Generic Scan Tool (OBDII scan tool) complying with SAE J1978 has
8 different functions explained below.
ISO15765-4 is used as the protocol.
The name GST or Generic Scan Tool is used in this service manual.
FUNCTION
Test mode Test item Corresponding DTC No. Reference page
EVAPORATIVE
SYSTEM PURG FLOW P0441 P0441
EC-210
EVP SML LEAK P0442/P1442*P0442
EC-215P0455EC-250
EVP V/S LEAK P0456/P1456* P0456 EC-257
PURG VOL CN/V P1444 P0443EC-222
A/F SEN1A/F SEN1 (B1) P1276 P0130
EC-136A/F SEN1 (B1) P1278/P1279 P0133EC-146
A/F SEN1 (B2) P1286 P0150EC-136
A/F SEN1 (B2) P1288/P1289 P0153EC-146
HO2S2HO2S2 (B1) P0139 P0139
EC-164
HO2S2 (B1) P1146 P0138EC-157
HO2S2 (B1) P1147 P0137EC-152
HO2S2 (B2) P0159 P0159EC-164
HO2S2 (B2) P1166 P0158EC-157
HO2S2 (B2) P1167 P0157EC-152
SEF139P
Diagnostic test mode Function
Service $01 READINESS TESTS This diagnostic service gains access to current emission-related data values, including an-
alog inputs and outputs, digital inputs and outputs, and system status information.
Service $02 (FREEZE DATA) This diagnostic service gains access to emission-related data value which were stored by
ECM during the freeze frame. For details, refer to
EC-456, "DTC Index"
.
Service $03 DTCs This diagnostic service gains access to emission-related power train trouble codes which
were stored by ECM.
Service $04 CLEAR DIAG INFO This diagnostic service can clear all emission-related diagnostic information. This in-
cludes:
 Clear number of diagnostic trouble codes (Service $01)
 Clear diagnostic trouble codes (Service $03)
 Clear trouble code for freeze frame data (Service $01)
 Clear freeze frame data (Service $02)
 Reset status of system monitoring test (Service $01)
 Clear on board monitoring test results (Service $06 and $07)
Service $06 (ON BOARD TESTS) This diagnostic service accesses the results of on board diagnostic monitoring tests of
specific components/systems that are not continuously monitored.
Revision: December 20092009 QX56

EC-78
< COMPONENT DIAGNOSIS >[VK56DE]
TROUBLE DIAGNOSIS - SPECIFICATION VALUE
>> GO TO 8.
8.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F AL PHA-B2” in “SPEC” of “DATA MONITOR” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG >> GO TO 9.
9.PERFORM POWER BALANCE TEST
1. Perform “POWER BALANCE” in “ACTIVE TEST” mode.
2. Make sure that the each cylinder produces a momentary engine speed drop.
OK or NG
OK >> GO TO 12.
NG >> GO TO 10.
10.DETECT MALFUNCTIONING PART
1. Check the following.
- Ignition coil and its circuit (Refer to EC-404, "Diagnosis Procedure"
.)
- Fuel injector and its circuit (Refer to EC-392, "Diagnosis Procedure"
.)
- Intake air leakage
- Low compression pressure (Refer to EM-23, "Checking Compression Pressure"
.)
2. If NG, repair or replace the malfunctioning part.
If OK, replace fuel injector. (It may be caus ed by leakage from fuel injector or clogging.)
>> GO TO 11.
11 .CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F AL PHA-B2” in “SPEC” of “DATA MONITOR” mode, and make sure that the
each indication is within the SP value.
OK or NG
OK >> INSPECTION END
NG >> GO TO 12.
12.CHECK A/F SENSOR 1 FUNCTION
Perform all DTC Confirmation Procedure related with A/F sensor 1.
 For DTC P0130, P0150, refer to EC-136, "DTC Confirmation Procedure"
.
 For DTC P0131, P0151, refer to EC-140, "DTC Confirmation Procedure"
.
 For DTC P0132, P0132, refer to EC-143, "DTC Confirmation Procedure"
.
 For DTC P0133, P0153, refer to EC-146, "DTC Confirmation Procedure"
.
 For DTC P2A00, P2A03, refer to EC-377, "DTC Confirmation Procedure"
.
OK or NG
OK >> GO TO 15.
NG >> GO TO 13.
13.CHECK A/F SENSOR 1 CIRCUIT
Perform Diagnostic Procedure according to corresponding DTC.
>> GO TO 14.
14.CHECK “A/F ALPHA-B1”, “A/F ALPHA-B2”
1. Start engine.
2. Select “A/F ALPHA-B1”, “A/F AL PHA-B2” in “SPEC” of “DATA MONITOR” mode, and make sure that the
each indication is within the SP value.
OK or NG
Revision: December 20092009 QX56

EC-94
< COMPONENT DIAGNOSIS >[VK56DE]
P0031, P0032, P0051, P00
52 A/F SENSOR 1 HEATER
P0031, P0032, P0051, P0052 A/F SENSOR 1 HEATER
DescriptionINFOID:0000000003771338
SYSTEM DESCRIPTION
The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to the engine operating
condition to keep the temperature of A/F sensor 1 element at the specified range.
On Board Diagnosis LogicINFOID:0000000003771339
DTC Confirmation ProcedureINFOID:0000000003771340
NOTE:
If DTC Confirmation Procedure has been previously conducted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following pr ocedure, confirm that battery voltage is between 10.5V and 16V at
idle.
1. Start engine and let it idle for at least 10 seconds.
2. Check 1st trip DTC.
3. If 1st trip DTC is detected, go to EC-94, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771341
1.CHECK GROUND CONNECTIONS
1. Turn ignition switch OFF.
2. Loosen and retighten three ground screws on the body.
Sensor Input Signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS) Engine speed
Air fuel ratio (A/F) sensor 1
heater control Air fuel ratio (A/F) sensor 1
heater
Mass air flow sensor Amount of intake air
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0031
0031
(Bank 1) Air fuel ratio (A/F) sensor
1 heater control circuit low The current amperage in the air fuel ratio (A/F) sen-
sor 1 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the air fuel ratio (A/F) sensor 1 heater.)  Harness or connectors
(The A/F sensor 1 heater circuit is
open or shorted.)
 A/F sensor 1 heater
P0051
0051
(Bank 2)
P0032
0032
(Bank 1)
Air fuel ratio (A/F) sensor
1 heater control circuit
high The current amperage in the air fuel ratio (A/F) sen-
sor 1 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the air fuel ratio (A/F) sensor 1 heater.)  Harness or connectors
(The A/F sensor 1 heater circuit is
shorted.)
 A/F sensor 1 heater
P0052
0052
(Bank 2)
Revision: December 20092009 QX56

P0037, P0038, P0057, P0058 HO2S2 HEATER
EC-97
< COMPONENT DIAGNOSIS > [VK56DE]
C
D
E
F
G H
I
J
K L
M A
EC
NP
O
P0037, P0038, P0057, P0058 HO2S2 HEATER
DescriptionINFOID:0000000003771343
SYSTEM DESCRIPTION
The ECM performs ON/OFF control of the heated o
xygen sensor 2 heater corresponding to the engine speed,
amount of intake air and engine coolant temperature.
OPERATION
On Board Diagnosis LogicINFOID:0000000003771344
DTC Confirmation ProcedureINFOID:0000000003771345
NOTE:
If DTC Confirmation Procedure has been previously conduc ted, always perform the following before conduct-
ing the next step.
1. Turn ignition swich OFF and wait at least 10 seconds.
2. Turn ignition swich ON.
3. Turn ignition swich OFF and wait at least 10 seconds.
TESTING CONDITION:
Before performing the following procedure, confi rm that battery voltage is between 10.5V and 16V at
idle.
1. Turn ignition switch ON and select “DATA MONITOR” mode with CONSULT-III.
2. Start engine and warm it up to the normal operating temperature.
3. Turn ignition switch OFF and wait at least 10 seconds.
4. Start the engine and keep the engine speed between 3,500 rpm and 4,000 rpm for at least 1 minute under no load.
5. Let engine idle for 1 minute.
Sensor Input signal to ECM ECM function Actuator
Camshaft position sensor (PHASE)
Crankshaft position sensor (POS) Engine speed
Heated oxygen sensor 2
heater controlHeated oxygen sensor 2 heater
Engine coolant temperature sensor Engine coolant temperature
Mass air flow sensor Amount of intake air
Engine speed (rpm) Heated oxygen sensor 2 heater
Above 3,600 OFF
Below 3,600 rpm after the following conditions are met.
 Engine: After warming up
 Keeping the engine speed between 3,500 and 4,000 rpm for 1 minute and at idle for 1 minute under no load ON
DTC No. Trouble diagnosis name DTC detecting condition Possible cause
P0037
0037
(Bank 1) Heated oxygen sensor 2
heater control circuit low The current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively low voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)  Harness or connectors
(The heated oxygen sensor 2 heater
circuit is open or shorted.)
 Heated oxygen sensor 2 heater
P0057
0057
(Bank 2)
P0038
0038
(Bank 1)
Heated oxygen sensor 2
heater control circuit high The current amperage in the heated oxygen sen-
sor 2 heater circuit is out of the normal range.
(An excessively high voltage signal is sent to ECM
through the heated oxygen sensor 2 heater.)  Harness or connectors
(The heated oxygen sensor 2 heater
circuit is shorted.)
 Heated oxygen sensor 2 heater
P0058
0058
(Bank 2)
Revision: December 20092009 QX56