2007 INFINITI QX56 DTC

AT-10
< SERVICE INFORMATION >
PRECAUTIONS
• The self-diagnostic results indicated by the MIL are automatically stored in both the ECM and TCM memo-
ries.
Always perform the procedure on AT-39, "
OBD-II Diagnostic Trouble Code (DTC)" to complete the
repair and avoid unnecessary blinking of the MIL.
For details of OBD-II, refer to EC-48
.
•Certain systems and components, especially those related to OBD, may use the new style slide-lock-
ing type harness connector. For description and how to disconnect, refer to PG-66
.

ON BOARD DIAGNOSTIC (OBD) SYSTEM
AT-39
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ON BOARD DIAGNOSTIC (OBD) SYSTEM
IntroductionINFOID:0000000003532238
The A/T system has two self-diagnostic systems.
The first is the emission-related on board diagnostic system (OBD-II) performed by the TCM in combination
with the ECM. The malfunction is indicated by the MIL (malfunction indicator lamp) and is stored as a DTC in
the ECM memory but not the TCM memory.
The second is the TCM original self-diagnosis indicated by the A/T CHECK indicator lamp. The malfunction is
stored in the TCM memory. The detected items are overlapped with OBD-II self-diagnostic items. For detail,
refer to AT-83, "
CONSULT-II Function (A/T)".
OBD-II Function for A/T SystemINFOID:0000000003532239
The ECM provides emission-related on board diagnostic (OBD-II) functions for the A/T system. One function
is to receive a signal from the TCM used with OBD-related parts of the A/T system. The signal is sent to the
ECM when a malfunction occurs in the corresponding OBD-related part. The other function is to indicate a
diagnostic result by means of the MIL (malfunction indicator lamp) on the instrument panel. Sensors, switches
and solenoid valves are used as sensing elements.
The MIL automatically illuminates in One or Two Trip Detection Logic when a malfunction is sensed in relation
to A/T system parts.
One or Two Trip Detection Logic of OBD-IIINFOID:0000000003532240
ONE TRIP DETECTION LOGIC
If a malfunction is sensed during the first test drive, the MIL will illuminate and the malfunction will be stored in
the ECM memory as a DTC. The TCM is not provided with such a memory function.
TWO TRIP DETECTION LOGIC
When a malfunction is sensed during the first test drive, it is stored in the ECM memory as a 1st trip DTC
(diagnostic trouble code) or 1st trip freeze frame data. At this point, the MIL will not illuminate. — 1st Trip
If the same malfunction as that experienced during the first test drive is sensed during the second test drive,
the MIL will illuminate. — 2nd Trip
The “Trip” in the “One or Two Trip Detection Logic” means a driving mode in which self-diagnosis is performed
during vehicle operation.
OBD-II Diagnostic Trouble Code (DTC)INFOID:0000000003532241
HOW TO READ DTC AND 1ST TRIP DTC
DTC and 1st trip DTC can be read by the following methods.
( with CONSULT-II or GST) CONSULT-II or GST (Generic Scan Tool) Examples: P0705, P0720 etc.
These DTC are prescribed by SAE J2012.
(CONSULT-II also displays the malfunctioning component or system.)
•1st trip DTC No. is the same as DTC No.
•Output of the diagnostic trouble code indicates that the indicated circuit has a malfunction. How-
ever, in case of the Mode II and GST, they do not indicate whether the malfunction is still occurring or
occurred in the past and returned to normal.
CONSULT-II can identify them as shown below, therefore, CONSULT-II (if available) is recommended.
A sample of CONSULT-II display for DTC and 1st trip DTC is shown
on the next page. DTC or 1st trip DTC of a malfunction is displayed
in SELF-DIAGNOSTIC RESULTS mode for “ENGINE” with CON-
SULT-II. Time data indicates how many times the vehicle was driven
after the last detection of a DTC.
BCIA0030E

AT-40
< SERVICE INFORMATION >
ON BOARD DIAGNOSTIC (OBD) SYSTEM
If the DTC is being detected currently, the time data will be “0”.
If a 1st trip DTC is stored in the ECM, the time data will be “1t”.
Freeze Frame Data and 1st Trip Freeze Frame Data
The ECM has a memory function, which stores the driving condition such as fuel system status, calculated
load value, engine coolant temperature, short term fuel trim, long term fuel trim, engine speed and vehicle
speed at the moment the ECM detects a malfunction.
Data which are stored in the ECM memory, along with the 1st trip DTC, are called 1st trip freeze frame data,
and the data, stored together with the DTC data, are called freeze frame data and displayed on CONSULT-II
or GST. The 1st trip freeze frame data can only be displayed on the CONSULT-II screen, not on the GST. For
detail, refer to AT- 3 9
.
Only one set of freeze frame data (either 1st trip freeze frame data of freeze frame data) can be stored in the
ECM. 1st trip freeze frame data is stored in the ECM memory along with the 1st trip DTC. There is no priority
for 1st trip freeze frame data and it is updated each time a different 1st trip DTC is detected. However, once
freeze frame data (2nd trip detection/MIL on) is stored in the ECM memory, 1st trip freeze frame data is no
longer stored. Remember, only one set of freeze frame data can be stored in the ECM. The ECM has the fol-
lowing priorities to update the data.
Both 1st trip freeze frame data and freeze frame data (along with the DTC) are cleared when the ECM mem-
ory is erased.
HOW TO ERASE DTC
The diagnostic trouble code can be erased by CONSULT-II, GST or ECM DIAGNOSTIC TEST MODE as
described following.
•If the battery cable is disconnected, the diagnostic trouble code will be lost within 24 hours.
•When you erase the DTC, using CONSULT-II or GST is easier and quicker than switching the mode
selector on the ECM.
The following emission-related diagnostic information is cleared from the ECM memory when erasing DTC
related to OBD-II. For details, refer to EC-49, "
Emission-related Diagnostic Information".
•Diagnostic trouble codes (DTC)
•1st trip diagnostic trouble codes (1st trip DTC)
•Freeze frame data
•1st trip freeze frame data
SAT015K
SAT016K
Priority Items
1 Freeze frame data Misfire — DTC: P0300 - P0306
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

ON BOARD DIAGNOSTIC (OBD) SYSTEM
AT-41
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•System readiness test (SRT) codes
•Test values
HOW TO ERASE DTC (WITH CONSULT-II)
•If a DTC is displayed for both ECM and TCM, it is necessary to be erased for both ECM and TCM.
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 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.)
HOW TO ERASE DTC (WITH GST)
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. Select Mode 4 with the Generic Scan Tool (GST). For details refer to EC-122, "
Generic Scan Tool (GST)
Function".
HOW TO ERASE DTC (NO TOOLS)
1. Disconnect battery for 24 hours.
2. Reconnect battery.
Malfunction Indicator Lamp (MIL)INFOID:0000000003532242
DESCRIPTION
SCIA5671E

TROUBLE DIAGNOSIS
AT-43
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TROUBLE DIAGNOSIS
DTC Inspection Priority ChartINFOID:0000000003532243
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC U1000 is displayed with other DTCs, first perform the trouble diagnosis for DTC U1000. Refer to
AT- 9 1
.
Fail-SafeINFOID:0000000003532244
The TCM has an electrical fail-safe mode. This mode makes it possible to operate even if there is an error in a
main electronic control input/output signal circuit. In fail-safe mode the transmission is fixed in 2nd, 4th or 5th
(depending on the breakdown position), so the customer should feel “slipping” or “poor acceleration”.
Even when the electronic circuits are normal, under special conditions (for example, when slamming on the
brake with the wheels spinning drastically and stopping the tire rotation), the transmission can go into fail-safe
mode. If this happens, switch “OFF” the ignition switch for 10 seconds, then switch it “ON” again to return to
the normal shift pattern. Therefore, the customer's vehicle has returned to normal, so handle according to the
“diagnostics flow” (Refer to AT-44, "
How To Perform Trouble Diagnosis for Quick and Accurate Repair").
FAIL-SAFE FUNCTION
If any malfunction occurs in a sensor or solenoid, this function controls the A/T to mark driving possible.
Vehicle Speed Sensor
• Signals are input from two systems - from vehicle speed sensor A/T (revolution sensor) installed on the
transmission and from combination meter so normal driving is possible even if there is a malfunction in one
of the systems. And if vehicle speed sensor A/T (revolution sensor) has unusual cases, 5th gear is prohib-
ited.
Accelerator Pedal Position Sensor
• If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM according
to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow sys-
tems, the engine speed is fixed by ECM to a pre-determined engine speed to make driving possible.
Throttle Position Sensor
• If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM according
to a pre-determined accelerator angle to make driving possible. And if there are malfunctions in tow sys-
tems, the accelerator opening angle is controlled by the idle signal sent from the ECM which is based on
input indicating either idle condition or off-idle condition (pre-determined accelerator opening) in order to
make driving possible.
PNP Switch
• In the unlikely event that a malfunction signal enters the TCM, the position indicator is switched “OFF”, the
starter relay is switched “OFF” (starter starting is disabled), the back-up lamp relay switched “OFF” (back-up
lamp is OFF) and the position is fixed to the “D” range to make driving possible.
Starter Relay
• The starter relay is switched “OFF”. (Starter starting is disabled.)
A/T Interlock
• If there is an A/T interlock judgment malfunction, the transmission is fixed in 2nd gear to make driving possi-
ble.
NOTE:
When the vehicle is driven fixed in 2nd gear, a turbine revolution sensor malfunction is displayed,
but this is not a turbine revolution sensor malfunction.
• When the coupling pattern below is detected, the fail-safe action corresponding to the pattern is performed.
A/T INTERLOCK COUPLING PATTERN TABLE
Priority Detected items (DTC)
1 U1000 CAN communication line
2 Except above

TROUBLE DIAGNOSIS
AT-85
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X: Applicable, —: Not applicable
Items (CONSULT-II
screen terms)Malfunction is detected when...TCM self-di-
agnosisOBD-II (DTC)
“A/T” with
CONSULT-IIMIL indicator
lamp*1, “EN-
GINE” with
CONSULT-II or
GST
CAN COMM CIRCUIT • When a malfunction is detected in CAN communications U1000 U1000
STARTER RELAY/
CIRC• If this signal is ON other than in P or N position, this is judged to be a
malfunction.
(And if it is OFF in P or N position, this too is judged to be a malfunction.)P0615 —
TCM • TCM is malfunctioning. P0700 P0700
PNP SW/CIRC• PNP switch 1-4 signals input with impossible pattern
• “P” position is detected from N position without any other position being
detected in between.P0705 P0705
TURBINE REV S/CIRC• TCM does not receive the proper voltage signal from the sensor.
• TCM detects an irregularity only at position of 4th gear for turbine revo-
lution sensor 2.P0717 P0717
VEH SPD SEN/CIR AT
(Revolution sensor)• Signal from vehicle speed sensor A/T (Revolution sensor) not input due
to cut line or the like
• Unexpected signal input during running
• After ignition switch is turned ON, unexpected signal input from vehicle
speed sensor MTR before the vehicle starts movingP0720 P0720
ENGINE SPEED SIG • TCM does not receive the CAN communication signal from the ECM. P0725 —
TCC SOLENOID/CIRC • Normal voltage not applied to solenoid due to cut line, short, or the like P0740 P0740
A/T TCC S/V FNCTN• A/T cannot perform lock-up even if electrical circuit is good.
• TCM detects as irregular by comparing difference value with slip rota-
tion.P0744 P0744*2
L/PRESS SOL/CIRC• Normal voltage not applied to solenoid due to cut line, short, or the like
• TCM detects as irregular by comparing target value with monitor value.P0745 P0745
TP SEN/CIRC A/T• TCM does not receive the proper accelerator pedal position signals (in-
put by CAN communication) from ECM.P1705 P1705
ATF TEMP SEN/CIRC• During running, the ATF temperature sensor signal voltage is exces-
sively high or lowP1710 P0710
VEH SPD SE/CIR·MTR• Signal (CAN communication) from vehicle speed sensor MTR not input
due to cut line or the like
• Unexpected signal input during runningP1721 —
A/T INTERLOCK• Except during shift change, the gear position and ATF pressure switch
states are monitored and comparative judgement made.P1730 P1730
A/T 1ST E/BRAKING• Each ATF pressure switch and solenoid current is monitored and if a
pattern is detected having engine braking 1st gear other than in the "1"
position, a malfunction is detected.P1731 —
I/C SOLENOID/CIRC• Normal voltage not applied to solenoid due to functional malfunction,
cut line, short, or the like
• TCM detects as irregular by comparing target value with monitor value.P1752 P1752
I/C SOLENOID FNCTN • TCM detects that actual gear ratio is irregular, and relation between
gear position and condition of ATF pressure switch 3 is irregular during
depressing accelerator pedal. (Other than during shift change)
• TCM detects that relation between gear position and condition of ATF
pressure switch 3 is irregular during releasing accelerator pedal. (Other
than during shift change)P1754 P1754*2
FR/B SOLENOID/CIRC• Normal voltage not applied to solenoid due to functional malfunction,
cut line, short, or the like
• TCM detects as irregular by comparing target value with monitor value.P1757 P1757

AT-86
< SERVICE INFORMATION >
TROUBLE DIAGNOSIS
*1: Refer to EC-63, "Malfunction Indicator Lamp (MIL)".
*2:These malfunctions cannot be displayed MIL if another malfunction is assigned to MIL.
DATA MONITOR MODE
Display Items List
FR/B SOLENOID FNCT• TCM detects that actual gear ratio is irregular, and relation between
gear position and condition of ATF pressure switch 1 is irregular during
depressing accelerator pedal. (Other than during shift change)
• TCM detects that relation between gear position and condition of ATF
pressure switch 1 is irregular during releasing accelerator pedal. (Other
than during shift change)P1759 P1759*2
D/C SOLENOID/CIRC• Normal voltage not applied to solenoid due to cut line, short, or the like
• TCM detects as irregular by comparing target value with monitor value.P1762 P1762
D/C SOLENOID
FNCTN• TCM detects that actual gear ratio is irregular, and relation between
gear position and condition of ATF pressure switch 5 is irregular during
depressing accelerator pedal. (Other than during shift change)
• TCM detects that relation between gear position and condition of ATF
pressure switch 5 is irregular during releasing accelerator pedal. (Other
than during shift change)P1764 P1764*2
HLR/C SOL/CIRC• Normal voltage not applied to solenoid due to functional malfunction,
cut line, short, or the like
• TCM detects as irregular by comparing target value with monitor value.P1767 P1767
HLR/C SOL FNCTN• TCM detects that actual gear ratio is irregular, and relation between
gear position and condition of ATF pressure switch 6 is irregular during
depressing accelerator pedal. (Other than during shift change)
• TCM detects that relation between gear position and condition of ATF
pressure switch 6 is irregular during releasing accelerator pedal. (Other
than during shift change)P1769 P1769*2
LC/B SOLENOID/CIRC• Normal voltage not applied to solenoid due to functional malfunction,
cut line, short, or the likeP1772 P1772
LC/B SOLENOID FNCT• TCM detects an improper voltage drop when it tries to operate the so-
lenoid valve.
• Condition of ATF pressure switch 2 is different from monitor value, and
relation between gear position and actual gear ratio is irregular.P1774 P1774*2
ATF PRES SW 1/CIRC• TCM detects that actual gear ratio is normal, and relation between gear
position and condition of ATF pressure switch 1 is irregular during de-
pressing accelerator pedal. (Other than during shift change)P1841 —
ATF PRES SW 3/CIRC• TCM detects that actual gear ratio is normal, and relation between gear
position and condition of ATF pressure switch 3 is irregular during de-
pressing accelerator pedal. (Other than during shift change)P1843 —
ATF PRES SW 5/CIRC• TCM detects that actual gear ratio is normal, and relation between gear
position and condition of ATF pressure switch 5 is irregular during de-
pressing accelerator pedal. (Other than during shift change)P1845 —
ATF PRES SW 6/CIRC• TCM detects that actual gear ratio is normal, and relation between gear
position and condition of ATF pressure switch 6 is irregular during de-
pressing accelerator pedal. (Other than during shift change)P1846 —
NO DTC IS DETECTED
FURTHER TESTING
MAY BE REQUIRED• No NG item has been detected. X X Items (CONSULT-II
screen terms)Malfunction is detected when...TCM self-di-
agnosisOBD-II (DTC)
“A/T” with
CONSULT-IIMIL indicator
lamp*1, “EN-
GINE” with
CONSULT-II or
GST

TROUBLE DIAGNOSIS
AT-89
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DTC WORK SUPPORT MODE
Display Items List
ATF WARN LAMP (ON-OFF display) — — X
BACK-UP LAMP (ON-OFF display) — — X
STARTER RELAY (ON-OFF display) — — X
PNP SW3 MON (ON-OFF display) — — X
C/V CLB ID1 — — X
C/V CLB ID2 — — X
C/V CLB ID3 — — X
UNIT CLB ID1 — — X
UNIT CLB ID2 — — X
UNIT CLB ID3 — — X
TRGT GR RATIO — — X
TRGT PRES TCC (kPa) — — X
TRGT PRES L/P (kPa) — — X
TRGT PRES I/C (kPa) — — X
TRGT PRE FR/B (kPa) — — X
TRGT PRES D/C (kPa) — — X
TRG PRE HLR/C (kPa) — — X
SHIFT PATTERN — — X
DRV CST JUDGE — — X
START RLY MON — — X
NEXT GR POSI — — X
SHIFT MODE — — X
MANU GR POSI — — X
VEHICLE SPEED (km/h) — XX Vehicle speed recognized by the TCM.
Voltage (V) — — XDisplays the value measured by the voltage
probe.
Frequency (Hz) — — X
The value measured by the pulse probe is dis-
played. DUTY-HI (high) (%) — — X
DUTY-LOW (low) (%) — — X
PLS WIDTH-HI (ms) — — X
PLS WIDTH-LOW (ms) — — XMonitored item (Unit)Monitor Item Selection
Remarks ECU IN-
PUT SIG-
NALSMAIN SIG-
NALSSELEC-
TION
FROM
MENU
DTC work support itemDescription Check item
I/C SOL FUNCTN CHECK* — —
FR/B SOL FUNCTN CHECK* — —
D/C SOL FUNCTN CHECK* — —
HLR/C SOL FUNCTN CHECK* — —