Page 1253 of 3419

EC-62Revision: October 2005
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
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-8, "
INDEX FOR DTC" ), 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”.
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.)
HO2S
HEATERA/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. 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
Page 1270 of 3419
BASIC SERVICE PROCEDURE
EC-79
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: October 20052005 QX56
Idle Mixture Ratio AdjustmentUBS00KZW
PREPARATION
1. Make sure that the following parts are in good order.
Battery
Ignition system
Engine oil and coolant levels
Fuses
ECM harness connector
Vacuum hoses
Air intake system
(Oil filler cap, oil level gauge, etc.)
Fuel pressure
Engine compression
Throttle valve
Evaporative emission system
2. On air conditioner equipped models, checks should be carried out while the air conditioner is OFF.
3. Checks should be carried out while selector lever is in P or N position.
4. When measuring CO percentage, insert probe more than 40 cm (15.7 in) into tail pipe.
5. Turn off headlamp, heater blower, rear window defogger.
6. Keep front wheels pointed straight ahead.
Page 1293 of 3419

EC-102Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
2P0037 P0038 P0057 P0058 Heated oxygen sensor 2 heater
P0138 P0139 P0158 P0159 P1146 P1147 P1166 P1167 Heated oxygen sensor 2
P0441 EVAP control system purge flow monitoring
P0444 P0445 P1444 EVAP canister purge volume control solenoid valve
P0447 P1446 EVAP canister vent control valve
P0451 P0452 P0453 EVAP control system pressure sensor
P0550 Power steering pressure sensor
P0700 P0710 P0720 P0740 P0744 P0745 P1716 P1730 P1752 P1754 P1757 P1759 P1762 P1764 P1767 P1769
P1772 P1774 A/T related sensors and solenoid valves
P1031 P1032 P1051 P1052 A/F sensor 1 heater
P1065 ECM power supply
P1122 Electric throttle control function
P1124 P1126 P1128 Electric throttle control actuator
P1217 Engine over temperature (OVERHEAT)
P1271 P1272 P1273 P1274 P1276 P1278 P1279 P1281 P1282 P1283 P1284 P1286 P1288 P1289 A/F sensor 1
P1805 Brake switch
3
P0171 P0172 P0174 P0175 Fuel injection system function
P0300 - P0308 Misfire
P0420 P0430 Three way catalyst function
P0442 P0455 P0456 EVAP control system
P0506 P0507 Idle speed control system
P1121 Electric throttle control actuator
P1148 P1168 Closed loop control
P1211 TCS control unit
P1212 TCS communication line
P1564 ICC/ASCD steering switch
P1568 ICC command value
P1572 ICC/ASCD brake switch
P1574 ICC/ASCD vehicle speed sensor Priority Detected items (DTC)
Page 1308 of 3419

TROUBLE DIAGNOSIS
EC-117
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: October 20052005 QX56
ECM Harness Connector Terminal LayoutUBS00L09
ECM Terminals and Reference ValueUBS00L0A
PREPARATION
1. ECM is located in the engine room passenger side behind bat-
tery.
2. Remove ECM harness connector.
3. When disconnecting ECM harness connector, loosen it with
levers as far as they will go as shown in the figure.
4. Connect a break-out box (SST) and Y-cable adapter (SST)
between the ECM and ECM harness connector.
Use extreme care not to touch 2 pins at one time.
Data is for comparison and may not be exact.
ECM INSPECTION TABLE
Specification data are reference values and are measured between each terminal and ground.
Pulse signal is measured by CONSULT-II.
CAUTION:
Do not use ECM ground terminals when measuring input/output voltage. Doing so may result in dam-
age to the ECMs transistor. Use a ground other than ECM terminals, such as the ground.
MBIB0045E
BBIA0386E
BBIA0387E
TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
1 B ECM ground[Engine is running]
Idle speedBody ground
2O/BA/F sensor 1 heater
(bank 1)[Engine is running]
Warm-up condition
Idle speedApproximately 5V
PBIB1584E
Page 1309 of 3419
![INFINITI QX4 2005 Factory Service Manual EC-118Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
3LThrottle control motor relay
power supply[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
4 L/W Throttle control motor (Close)[Ignition switc INFINITI QX4 2005 Factory Service Manual EC-118Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
3LThrottle control motor relay
power supply[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
4 L/W Throttle control motor (Close)[Ignition switc](/manual-img/42/57035/w960_57035-1308.png)
EC-118Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
3LThrottle control motor relay
power supply[Ignition switch: ON]BATTERY VOLTAGE
(11 - 14V)
4 L/W Throttle control motor (Close)[Ignition switch: ON]
Engine: Stopped
Selector lever: D
Accelerator pedal: Fully released0 - 14V
5 L/B Throttle control motor (Open)[Ignition switch: ON]
Engine: Stopped
Selector lever: D
Accelerator pedal: Fully depressed0 - 14V
6GRHeated oxygen sensor 2
heater (bank 1)[Engine is running]
Warm-up condition
Engine speed is below 3,600 rpm after the
following conditions are met.
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load0 - 1.0V
[Ignition switch: ON]
Engine: Stopped
[Engine is running]
Engine speed: Above 3,600 rpmBATTERY VOLTAGE
(11 - 14V)
12 RPower steering pressure sen-
sor[Engine is running]
Steering wheel: Being turned0.5 - 4.5V
[Engine is running]
Steering wheel: Not being turned0.4 - 0.8V
13 OCrankshaft position sensor
(POS)[Engine is running]
Warm-up condition
Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idleApproximately 10V
[Engine is running]
Engine speed: 2,000 rpmApproximately 10V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
PBIB1104E
PBIB1105E
PBIB1041E
PBIB1042E
Page 1310 of 3419
![INFINITI QX4 2005 Factory Service Manual TROUBLE DIAGNOSIS
EC-119
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: October 20052005 QX56
14 YCamshaft position sensor
(PHASE)[Engine is running]
Warm-up condition
Idle speed
NOTE:
The pulse cycle changes INFINITI QX4 2005 Factory Service Manual TROUBLE DIAGNOSIS
EC-119
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: October 20052005 QX56
14 YCamshaft position sensor
(PHASE)[Engine is running]
Warm-up condition
Idle speed
NOTE:
The pulse cycle changes](/manual-img/42/57035/w960_57035-1309.png)
TROUBLE DIAGNOSIS
EC-119
C
D
E
F
G
H
I
J
K
L
MA
EC
Revision: October 20052005 QX56
14 YCamshaft position sensor
(PHASE)[Engine is running]
Warm-up condition
Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idle1.0 - 4.0V
[Engine is running]
Engine speed: 2,000 rpm1.0 - 4.0V
15 W Knock sensor (bank 1)[Engine is running]
Idle speedApproximately 2.5V
16 BR/R
A/F sensor 1 (bank 1)[Engine is running]
Warm-up condition
Idle speedApproximately 3.1V
35 BR/GApproximately 2.6V
56 LG/BApproximately 2.3V
75 P/BApproximately 2.3V
21
22
23
44O/L
BR
GR/W
OInjector No. 5
Injector No. 3
Injector No. 1
Injector No. 7[Engine is running]
Warm-up condition
Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idleBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
Warm-up condition
Engine speed: 2,000 rpmBATTERY VOLTAGE
(11 - 14V)
24 BR/WA/F sensor 1 heater
(bank 2)[Engine is running]
Warm-up condition
Idle speedApproximately 5V TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
PBIB1039E
PBIB1040E
SEC984C
SEC985C
PBIB1584E
Page 1311 of 3419
![INFINITI QX4 2005 Factory Service Manual EC-120Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
25 O/GHeated oxygen sensor 2
heater (bank 2)[Engine is running]
Warm-up condition
Engine speed is below 3,600 rpm after the
following condi INFINITI QX4 2005 Factory Service Manual EC-120Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
25 O/GHeated oxygen sensor 2
heater (bank 2)[Engine is running]
Warm-up condition
Engine speed is below 3,600 rpm after the
following condi](/manual-img/42/57035/w960_57035-1310.png)
EC-120Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
25 O/GHeated oxygen sensor 2
heater (bank 2)[Engine is running]
Warm-up condition
Engine speed is below 3,600 rpm after the
following conditions are met.
–Keeping the engine speed between 3,500
and 4,000 rpm for 1 minute and at idle for 1
minute under no load0 - 1.0V
[Ignition switch: ON]
Engine: Stopped
[Engine is running]
Engine speed: Above 3,600 rpmBATTERY VOLTAGE
(11 - 14V)
32 LEVAP control system pres-
sure sensor[Ignition switch: ON]Approximately 1.8 - 4.8V
34 R/B Intake air temperature sensor[Engine is running]Approximately 0 - 4.8V
Output voltage varies with intake
air temperature.
36 W Knock sensor (bank 2)[Engine is running]
Idle speedApproximately 2.5V
40
41
42
63Y/G
P
L
GInjector No. 6
Injector No. 4
Injector No. 2
Injector No. 8[Engine is running]
Warm-up condition
Idle speed
NOTE:
The pulse cycle changes depending on rpm
at idleBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
Warm-up condition
Engine speed: 2,000 rpmBATTERY VOLTAGE
(11 - 14V)
45 L/YEVAP canister purge volume
control solenoid valve[Engine is running]
Idle speed
Accelerator pedal: Not depressed even
slightly, after engine startingBATTERY VOLTAGE
(11 - 14V)
[Engine is running]
Engine speed: About 2,000 rpm (More than
100 seconds after starting engine)BATTERY VOLTAGE
(11 - 14V) TER-
MINAL
NO.WIRE
COLORITEM CONDITION DATA (DC Voltage)
SEC984C
SEC985C
SEC990C
SEC991C
Page 1319 of 3419

EC-128Revision: October 2005
TROUBLE DIAGNOSIS
2005 QX56
X: Applicable
*1: This item includes 1st trip DTCs.
*2: This mode includes 1st trip freeze frame data or freeze frame data. The items appear on CONSULT-II screen in freeze frame data
mode only if a 1st trip DTC or DTC is detected. For details, refer to EC-130, "
Freeze Frame Data and 1st Trip Freeze Frame Data" .
INSPECTION PROCEDURE
CAUTION:
If CONSULT-II is used with no connection of CONSULT-II CONVERTER, malfunctions might be
detected in self-diagnosis depending on control unit which carry out CAN communication.
1. Turn ignition switch OFF.
2. Connect “CONSULT-II” and “CONSULT-II CONVERTER” to
data link connector, which is located under LH dash panel near
the hood opener handle.
3. Turn ignition switch ON.
4. Touch “START (NISSAN BASED VHCL)”.
ENGINE CONTROL COMPONENT PARTS
OUTPUT
Fuel injector×× ×
Power transistor (Ignition timing)×× ×
Throttle control motor relay×××
Throttle control motor×
EVAP canister purge volume con-
trol solenoid valve×××××
Air conditioner relay××
Fuel pump relay××××
Cooling fan relay××××
Air fuel ratio (A/F) sensor 1 heater××××
Heated oxygen sensor 2 heater××××
EVAP canister vent control valve×× ×××
Calculated load value××× ItemDIAGNOSTIC TEST MODE
WORK
SUP-
PORTSELF-DIAGNOSTIC
RESULTS
DATA
MONI-
TORDATA
MONI-
TOR
(SPEC)ACTIVE
TESTDTC & SRT
CONFIRMATION
DTC*1FREEZE
FRAME
DATA*2SRT
STATUSDTC
WORK
SUP-
PORT
BBIA0369E
BCIA0029E