INFINITI QX4 2005 Factory Service Manual
Manufacturer: INFINITI, Model Year: 2005, Model line: QX4, Model: INFINITI QX4 2005Pages: 3419, PDF Size: 80.18 MB
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EC-60Revision: October 2005
ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
The time required for each diagnosis varies with road surface conditions, weather, altitude, individual driv-
ing habits, etc.
Zone A refers to the range where the time, required for the diagnosis under normal conditions*, is the
shortest.
Zone B refers to the range where the diagnosis can still be performed if the diagnosis is not completed
within zone A.
*: Normal conditions refer to the following:
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)], diag-
nosis 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 terminal 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 after it is interrupted, each diagnosis can be con-
ducted. 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 Transmission Gear Position
Set the selector lever in the D position with the overdrive switch turned ON.
PBIB2244E
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TEST VALUE AND TEST LIMIT (GST ONLY — NOT APPLICABLE TO CONSULT-II)
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 Test ID (TID) and Component ID (CID) and can be dis-
played on the GST screen.
Item Self-diagnostic test item DTCTest value (GST display)
Test limit Conversion
TID CID
CATALYST Three way catalyst function (Bank 1)
P0420 01H 01H Max. 1/128
P0420 02H 81H Min. 1
Three way catalyst function (Bank 2) P0430 03H 02H Max. 1/128
P0430 04H 82H Min. 1
EVAP
SYSTEM EVAP control system (Small leak) P0442 05H 03H Max.
1/128 mm
2
EVAP control system purge flow monitoring P0441 06H 83H Min. 20 mV
EVAP control system (Very small leak) P0456 07H 03H Max. 1/128 mm
2
HO2SAir fuel ratio (A/F) sensor 1 (Bank 1)
P1271 41H 8EH Min. 5mV
P1272 42H 0EH Max. 5mV
P1273 43H 0EH Max. 0.002
P1274 44H 8EH Min. 0.002
P1278
45H 8EH Min. 0.004
P1276 46H 0EH Max. 5mV
P1276 47H 8EH Min. 5mV
P1279 48H 8EH Min. 0.004
Air fuel ratio (A/F) sensor 1 (Bank 2) P1281 4CH 8FH Min. 5mV
P1282 4DH 0FH Max. 5mV
P1283 4EH 0FH Max. 0.002
P1284 4FH 8FH Min. 0.002
P1288
50H 8FH Min. 0.004
P1286 51H 0FH Max. 5mV
P1286 52H 8FH Min. 5mV
P1289 53H 8FH Min. 0.004
Heated oxygen sensor 2 (Bank 1) P0138 1CH 06H Max. 10mV
P0139 19H 86H Min. 10mV/500 ms
P1147 1AH 86H Min. 10 mV
P1146 1BH 06H Max. 10 mV
Heated oxygen sensor 2 (Bank 2) P0158 24H 07H Max. 10mV
P0159 21H 87H Min. 10 mV/500 ms
P1167 22H 87H Min. 10 mV
P1166 23H 07H Max. 10 mV
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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
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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-8, "
INDEX FOR DTC" ), 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-37, "
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-8, "
INDEX FOR DTC" ), 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-37, "
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-65, "
HOW TO SWITCH DIAGNOSTIC TEST MODE" .
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
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
–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.
Malfunction Indicator Lamp (MIL)UBS00KZS
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-30, "
WARNING LAMPS" ,
or see EC-667, "
MIL AND DATA LINK CONNECTOR" .
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.
SEF 2 17 U
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
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MIL Flashing Without DTC
When any SRT codes are not set, MIL may flash without DTC. For the details, refer to EC-57, "How to Display
SRT Status" .
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-57, "
How to Display SRT Status" .
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 EC-65, "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-
30, "WAR NIN G LAM PS" or see EC-667, "MIL AND DATA LINK CONNECTOR" .
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.
PBIB0092E
MIL Condition
ON When the malfunction is detected.
OFF No malfunction.
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2005 QX56
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
displayed, they may be either DTCs or 1st trip DTCs. DTC No. is same as that of 1st trip DTC. These uniden-
tified codes can be identified by using the CONSULT-II or GST. A DTC will be used as an example for how to
read a code.
A particular trouble code can be identified by the number of four-digit numeral flashes. The “zero” is indicated
by the number of ten flashes. The length of time the 1,000th-digit numeral flashes on and off is 1.2 seconds
consisting of an ON (0.6-second) - OFF (0.6-second) cycle.
The 100th-digit numeral and lower digit numerals consist of a 0.3-second ON and 0.3-second OFF cycle.
A change from one digit numeral to another occurs at an interval of 1.0-second OFF. In other words, the later
numeral appears on the display 1.3 seconds after the former numeral has disappeared.
A change from one trouble code to another occurs at an interval of 1.8-second OFF.
In this way, all the detected malfunctions are classified by their DTC numbers. The DTC 0000 refers to no mal-
function. (See EC-8, "
INDEX FOR DTC" )
How to Erase Diagnostic Test Mode II (Self-diagnostic Results)
The DTC can be erased from the back up memory in the ECM by depressing accelerator pedal. Refer to EC-
65, "How to Erase Diagnostic Test Mode II (Self-diagnostic Results)" .
If the battery is disconnected, the DTC will be lost from the backup memory within 24 hours.
Be careful not to erase the stored memory before starting trouble diagnoses.
OBD System Operation ChartUBS00KZT
RELATIONSHIP BETWEEN MIL, 1ST TRIP DTC, DTC, AND DETECTABLE ITEMS
When a malfunction is detected for the first time, the 1st trip DTC and the 1st trip freeze frame data are
stored in the ECM memory.
When the same malfunction is detected in two consecutive trips, the DTC and the freeze frame data are
stored in the ECM memory, and the MIL will come on. For details, refer to EC-48, "
Tw o Tr ip D e t e c t i o n
Logic" .
The MIL will go off after the vehicle is driven 3 times (driving pattern B) with no malfunction. The drive is
counted only when the recorded driving pattern is met (as stored in the ECM). If another malfunction
occurs while counting, the counter will reset.
The DTC and the freeze frame data will be stored until the vehicle is driven 40 times (driving pattern A)
without the same malfunction recurring (except for Misfire and Fuel Injection System). For Misfire and
Fuel Injection System, the DTC and freeze frame data will be stored until the vehicle is driven 80 times
(driving pattern C) without the same malfunction recurring. The “TIME” in “SELF-DIAGNOSTIC
RESULTS” mode of CONSULT-II will count the number of times the vehicle is driven.
The 1st trip DTC is not displayed when the self-diagnosis results in OK for the 2nd trip.
PBIA3905E
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SUMMARY CHART
For details about patterns B and C under “Fuel Injection System” and “Misfire”, see EC-69, "EXPLANATION FOR DRIVING PATTERNS
FOR “MISFIRE
For details about patterns A and B under Other, see EC-71, "
EXPLANATION FOR DRIVING PATTERNS EXCEPT FOR “MISFIRE
*1: Clear timing is at the moment OK is detected.
*2: Clear timing is when the same malfunction is detected in the 2nd trip.Items Fuel Injection System Misfire Other
MIL (goes off) 3 (pattern B) 3 (pattern B) 3 (pattern B)
DTC, Freeze Frame Data (no
display)80 (pattern C) 80 (pattern C) 40 (pattern A)
1st Trip DTC (clear)
1 (pattern C), *
11 (pattern C), *11 (pattern B)
1st Trip Freeze Frame Data
(clear)*1, *2 *1, *2 1 (pattern B)
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
2005 QX56
RELATIONSHIP BETWEEN MIL, DTC, 1ST TRIP DTC AND DRIVING PATTERNS FOR “MISFIRE
”
*1: When the same malfunction is
detected in two consecutive trips,
MIL will light up.*2: MIL will go off after vehicle is driven
3 times (pattern B) without any mal-
functions.*3: When the same malfunction is
detected in two consecutive trips, the
DTC and the freeze frame data will
be stored in ECM.
*4: The DTC and the freeze frame data
will not be displayed any longer after
vehicle is driven 80 times (pattern C)
without the same malfunction. (The
DTC and the freeze frame data still
remain in ECM.)*5: When a malfunction is detected for
the first time, the 1st trip DTC and
the 1st trip freeze frame data will be
stored in ECM.*6: The 1st trip DTC and the 1st trip
freeze frame data will be cleared at
the moment OK is detected.
*7: When the same malfunction is
detected in the 2nd trip, the 1st trip
freeze frame data will be cleared.*8: 1st trip DTC will be cleared when
vehicle is driven once (pattern C)
without the same malfunction after
DTC is stored in ECM.
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EXPLANATION FOR DRIVING PATTERNS FOR “MISFIRE
Driving pattern B means the vehicle operation as follows:
All components and systems should be monitored at least once by the OBD system.
The B counter will be cleared when the malfunction is detected once regardless of the driving pattern.
The B counter will be counted up when driving pattern B is satisfied without any malfunction.
The MIL will go off when the B counter reaches 3. (*2 in “OBD SYSTEM OPERATION CHART”)
Driving pattern C means the vehicle operation as follows:
The following conditions should be satisfied at the same time:
Engine speed: (Engine speed in the freeze frame data) ±375 rpm
Calculated load value: (Calculated load value in the freeze frame data) x (1±0.1) [%]
Engine coolant temperature (T) condition:
When the freeze frame data shows lower than 70°C (158°F), T should be lower than 70°C (158°F).
When the freeze frame data shows higher than or equal to 70°C (158°F), T should be higher than or equal
to 70°C (158°F).
Example:
If the stored freeze frame data is as follows:
Engine speed: 850 rpm, Calculated load value: 30%, Engine coolant temperature: 80°C (176°F)
To be satisfied with driving pattern C, the vehicle should run under the following conditions:
Engine speed: 475 - 1,225 rpm, Calculated load value: 27 - 33%, Engine coolant temperature: more than 70°C
(158°F)
The C counter will be cleared when the malfunction is detected regardless of vehicle conditions above.
The C counter will be counted up when vehicle conditions above is satisfied without the same malfunction.
The DTC will not be displayed after C counter reaches 80.
The 1st trip DTC will be cleared when C counter is counted once without the same malfunction after DTC
is stored in ECM.