2008 INFINITI QX56 ECU

ECM
EC-473
< ECU DIAGNOSIS > [VK56DE]
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• 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 te rminal 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 afte r 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 Transmi ssion Gear Position
Set the selector lever in the D position with the overdrive switch turned ON.
TEST VALUE AND TEST LIMIT
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 On Boad Monitor ID(OBDMID), Test ID (TID), Unit and
Scaling ID and can be displayed on the GST screen.
The items of the test value and test limit will be disp layed with GST screen which items are provided by the
ECM. (eg., if the bank 2 is not applied on this v ehicle, only the items of the bank 1 is displayed)
PBIB2244E
Revision: March 2010 2008 QX56

EC-474
< ECU DIAGNOSIS >[VK56DE]
ECM
ItemOBD-
MID Self-diagnostic test item
DTCTest 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 volt-
age
P0133 8CH 83H Response gain at the limited fre-
quency
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 volt-
age
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 volt-
age
Revision: March 2010
2008 QX56

ECM
EC-475
< ECU DIAGNOSIS > [VK56DE]
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HO2S 05H
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 volt-
age
P0153 8CH 83H Response gain at the limited fre-
quency
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 volt-
age
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 volt-
age
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 out-
put voltage
P2423 84H 84H O2 storage index in HC trap cata-
lyst
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 out-
put voltage
P2424 84H 84H O2 storage index in HC trap cata-
lyst
Item
OBD-
MID Self-diagnostic test item
DTCTest value and Test
limit
(GST display) Description
TID Unit and
Scaling ID
Revision: March 2010 2008 QX56

EC-476
< ECU DIAGNOSIS >[VK56DE]
ECM
EGR
SYSTEM31H EGR function P0400 80H 96H
Low Flow Faults: EGR temp
change rate (short term)
P0400 81H 96H Low Flow Faults: EGR temp
change rate (long term)
P0400 82H 96H Low Flow Faults: Difference be-
tween max EGR temp and EGR
temp under idling condition
P0400 83H 96H Low Flow Faults: Max EGR temp
P1402 84H 96H High Flow Faults: EGR temp in-
crease rate
EVAP
SYSTEM 39H
EVAP control
system leak
(Cap Off) P0455 80H 0CHDifference in pressure sensor out-
put voltage before and after pull
down
3BH EVAP control
system leak
(Small leak) P0442 80H 05H
Leak area index (for more than
0.04inch)
3CH EVAP control system
(Very small leak) P0456 80H 05H
Leak area index (for more than
0.02inch)
P0456 81H FDH Maximum internal pressure of
EVAP system during monitoring
3DH Purge flow system P0441 83H 0CHDifference in pressure sensor out-
put voltage before and after vent
control value close
O2 SEN-
SOR
HEATER 41H
A/F sensor 1 heater
(Bank 1) Low Input:P0031
High Input:P0032 81H 0BHConverted value of Heater electric
current to voltage
42H Heated oxygen sensor 2
(Bank 1) Low Input:P0037
High Input:P0038 80H 0CH
Converted value of Heater electric
current to voltage
43H Heated oxygen sensor 3
(Bank 1) P0043 80H 0CHConverted value of Heater electric
current to voltage
45H A/F sensor 1 heater
(Bank 2) Low Input:P0051
High Input:P0052 81H 0BHConverted value of Heater electric
current to voltage
46H Heated oxygen sensor 2
(Bank 2) Low Input:P0057
High Input:P0058 80H 0CHConverted value of Heater electric
current to voltage
47H Heated oxygen sensor 3
(Bank 2) P0063 80H 0CH
Converted value of Heater electric
current to voltage
SEC-
OND-
ARY AIR 71H Secondary Air system P0411 80H 01H
Secondary Air Injection System
Incorrect Flow Detected
Bank1: P0491
Bank2: P0492 81
H 0
1HSe
condary Air Injection System
Insufficient Flow
P2445 82H 01H Secondary Air Injection System
Pump Stuck Off
P2448 83H 01H Secondary Air Injection System
High Airflow
Bank1: P2440
Bank2: P2442 84H 01HSecondary Air Injection System
Switching Valve Stuck Open
P2440 85H 01H Secondary Air Injection System
Switching Valve Stuck Open
P2444 86H 01H Secondary Air Injection System
Pump Stuck On
Item
OBD-
MID Self-diagnostic test item
DTCTest value and Test
limit
(GST display) Description
TID Unit and
Scaling ID
Revision: March 2010 2008 QX56

ECM
EC-477
< ECU DIAGNOSIS > [VK56DE]
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FUEL
SYSTEM
81H
Fuel injection system function
(Bank 1) P0171 or P0172 80H 2FH Long term fuel trim
P0171 or P0172 81H 24H
The number of lambda control
clamped
82H Fuel injection system function
(Bank 2) P0174 or P0175 80H 2FH Long term fuel trim
P0174 or P0175 81H 24H
The number of lambda control
clamped
Item
OBD-
MID Self-diagnostic test item
DTCTest value and Test
limit
(GST display) Description
TID Unit and
Scaling ID
Revision: March 2010 2008 QX56

EC-478
< ECU DIAGNOSIS >[VK56DE]
ECM
MISFIREA1H Multiple Cylinder Misfire P0301 80H 24H
Misfiring counter at 1000rev of the
first cylinder
P0302 81H 24H Misfiring counter at 1000rev of the
second cylinder
P0303 82H 24H Misfiring counter at 1000rev of the
third cylinder
P0304 83H 24H Misfiring counter at 1000rev of the
fourth cylinder
P0305 84H 24H Misfiring counter at 1000rev of the
fifth cylinder
P0306 85H 24H Misfiring counter at 1000rev of the
sixth cylinder
P0307 86H 24H Misfiring counter at 1000rev of the
seventh cylinder
P0308 87H 24H Misfiring counter at 1000rev of the
eighth cylinder
P0300 88H 24H Misfiring counter at 1000rev of the
multiple cylinders
P0301 89H 24H Misfiring counter at 200rev of the
first cylinder
P0302 8AH 24H Misfiring counter at 200rev of the
second cylinder
P0303 8BH 24H Misfiring counter at 200rev of the
third cylinder
P0304 8CH 24H Misfiring counter at 200rev of the
fourth cylinder
P0305 8DH 24H Misfiring counter at 200rev of the
fifth cylinder
P0306 8EH 24H Misfiring counter at 200rev of the
fifth cylinder
P0307 8FH 24H Misfiring counter at 200rev of the
fifth cylinder
P0308 90H 24H Misfiring counter at 200rev of the
fifth cylinder
P0300 91H 24H Misfiring counter at 1000rev of the
single cylinder
P0300 92H 24H Misfiring counter at 200rev of the
single cylinder
P0300 93H 24H Misfiring counter at 200rev of the
multiple cylinders
A2H No.1 Cylinder Misfire P0301 0BH 24H
EWMA (Exponential Weighted
Moving Average) misfire counts
for last 10 driving cycles
P0301 0CH 24H Misfire counts for last/current driv-
ing cycles
Item
OBD-
MID Self-diagnostic test item
DTCTest value and Test
limit
(GST display) Description
TID Unit and
Scaling ID
Revision: March 2010 2008 QX56

ECM
EC-479
< ECU DIAGNOSIS > [VK56DE]
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HOW TO ERASE EMISSION-RELATED DIAGNOSTIC INFORMATION
How to Erase DTC
WITH CONSULT-III
The emission related diagnostic information in the ECM can be erased by selecting “All Erase” in the “Descrip-
tion” of “FINAL CHECK” mode with CONSULT-III.
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-462, "
DTC Index"), skip step 2.
1. If the ignition switch stays ON after repair work, be su re to turn ignition switch OFF once. Wait at least 10
seconds and then turn it ON (engine stopped) again.
2. Perform TM-30, "
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:
MISFIRE A3H No.2 Cylinder Misfire
P0302 0BH 24H
EWMA (Exponential Weighted
Moving Average) misfire counts
for last 10 driving cycles
P0302 0CH 24H Misfire counts for last/current driv-
ing cycles
A4H No.3 Cylinder Misfire P0303 0BH 24H
EWMA (Exponential Weighted
Moving Average) misfire counts
for last 10 driving cycles
P0303 0CH 24H Misfire counts for last/current driv-
ing cycles
A5H No.4 Cylinder Misfire P0304 0BH 24H
EWMA (Exponential Weighted
Moving Average) misfire counts
for last 10 driving cycles
P0304 0CH 24H Misfire counts for last/current driv-
ing cycles
A6H No.5 Cylinder Misfire P0305 0BH 24H
EWMA (Exponential Weighted
Moving Average) misfire counts
for last 10 driving cycles
P0305 0CH 24H Misfire counts for last/current driv-
ing cycles
A7H No.6 Cylinder Misfire P0306 0BH 24H
EWMA (Exponential Weighted
Moving Average) misfire counts
for last 10 driving cycles
P0306 0CH 24H Misfire counts for last/current driv-
ing cycles
A8H No.7 Cylinder Misfire P0307 0BH 24H
EWMA (Exponential Weighted
Moving Average) misfire counts
for last 10 driving cycles
P0307 0CH 24H Misfire counts for last/current driv-
ing cycles
A9H No.8 Cylinder Misfire P0308 0BH 24H
EWMA (Exponential Weighted
Moving Average) misfire counts
for last 10 driving cycles
P0308 0CH 24H Misfire counts for last/current driv-
ing cycles
Item
OBD-
MID Self-diagnostic test item
DTCTest value and Test
limit
(GST display) Description
TID Unit and
Scaling ID
Revision: March 2010 2008 QX56

EC-480
< ECU DIAGNOSIS >[VK56DE]
ECM
If the DTC is not for AT related items (see
EC-462, "DTC Index"), 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 TM-30, "
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-55, "
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
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.
Revision: March 2010 2008 QX56