2009 INFINITI QX56 electric

TM-60
< COMPONENT DIAGNOSIS >
P0734 4GR INCORRECT RATIO
P0734 4GR INCORRECT RATIO
DescriptionINFOID:0000000003771880
This malfunction is detected when the A/T does not shift into 4GR position as instructed by TCM. This is not
only caused by electrical malfunction (circuits open or shorted) but also by mechanical malfunction such as
control valve sticking, improper solenoid valve operation.
On Board Diagn osis LogicINFOID:0000000003771881
 This is an OBD-II self-diagnostic item.
 Diagnostic trouble code “P0734” is detected when TCM detec ts any inconsistency in the actual gear ratio.
Possible CauseINFOID:0000000003771882
 Harness or connectors
(Solenoid circuits are open or shorted.)
 Input clutch solenoid valve
 Front brake solenoid valve
 Direct clutch solenoid valve
 High and low reverse clutch solenoid valve
 Each clutch
 Hydraulic control circuit
DTC Confirmation ProcedureINFOID:0000000003771883
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously performed, alw ays turn ignition switch OFF and
wait at least 10 seconds before performing the next test.
After the repair, perform the following proc edure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Start the engine and select “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
2. Make sure that “ATF TEMP 1” is within the following range. ATF TEMP 1: 20 °C – 140 °C
If out of range, drive vehicle to warm ATF or stop engine to cool ATF.
3. Select “4TH GR FNCTN P0734” of “DTC WORK SUPPORT” mode for “TRANSMISSION” with CON-
SULT-III.
4. Drive vehicle and maintain the following conditions.
VEHICLE SPEED: 10 km/h (6 MPH) or more
ACCELE POSI: 0.6/8 or more
ENGINE SPEED: INPUT SPEED − 50 rpm or more
INPUT SPEED: 300 rpm or more
GEAR: “4” position
MANU MODE SW: ON
5. Keep the current driving status for at least 5 consecutive seconds if CONSULT-III screen changes from
“OUT OF CONDITION” to “TESTING”.
CAUTION:
If “TESTING” does not ap pear on CONSULT-III for a long ti me, select “SELF-DIAG RESULTS”. In
case a 1st trip DTC other than P0734 is shown, refer to “ TM-117, "DTC No. Index"
”.
If “COMPLETED RESULT NG” is detected, go to TM-61, "Diagnosis Procedure"
.
If “STOP VEHICLE” is detect ed, go to the following step.
6. Stop vehicle.
7. Drive vehicle in “D” position allowing it to shift from 1GR to 5GR and check shift timing and shift shock.
- Touch “OK” to complete the inspection when normally shifted from the 1GR to 5GR.
- Touch “NG” when an unusual shift shock, etc. occurs in spite of shifting from the 1GR to 5GR. Go to TM-
190, "Description".
- Perform TM-32, "CONSULT-III Function (TRANSMISSION)"
when not shifted from the 1GR to 5GR. (Nei-
ther “OK” nor “NG” are indicated.)
Revision: December 20092009 QX56

TM-62
< COMPONENT DIAGNOSIS >
P0735 5GR INCORRECT RATIO
P0735 5GR INCORRECT RATIO
DescriptionINFOID:0000000003771885
This malfunction is detected when the A/T does not shift into 5GR position as instructed by TCM. This is not
only caused by electrical malfunction (circuits open or shorted) but also by mechanical malfunction such as
control valve sticking, improper solenoid valve operation.
On Board Diagn osis LogicINFOID:0000000003771886
 This is an OBD-II self-diagnostic item.
 Diagnostic trouble code “P0735” is detected when TCM detec ts any inconsistency in the actual gear ratio.
Possible CauseINFOID:0000000003771887
 Harness or connectors
(Solenoid circuits are open or shorted.)
 Input clutch solenoid valve
 Front brake solenoid valve
 Direct clutch solenoid valve
 High and low reverse clutch solenoid valve
 Each clutch
 Hydraulic control circuit
DTC Confirmation ProcedureINFOID:0000000003771888
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously performed, alw ays turn ignition switch OFF and
wait at least 10 seconds before performing the next test.
After the repair, perform the following proc edure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Start the engine and select “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
2. Make sure that “ATF TEMP 1” is within the following range. ATF TEMP 1: 20 °C – 140 °C
If out of range, drive vehicle to warm ATF or stop engine to cool ATF.
3. Select “5TH GR FNCTN P0735” of “DTC WORK SUPPORT” mode for “TRANSMISSION” with CON-
SULT-III.
4. Drive vehicle and maintain the following conditions.
VEHICLE SPEED: 10 km/h (6 MPH) or more
ACCELE POSI: 0.6/8 or more
ENGINE SPEED: INPUT SPEED − 50 rpm or more
INPUT SPEED: 300 rpm or more
GEAR: “5” position
MANU MODE SW: ON
5. Keep the current driving status for at least 5 consecutive seconds if CONSULT-III screen changes from
“OUT OF CONDITION” to “TESTING”.
CAUTION:
If “TESTING” does not ap pear on CONSULT-III for a long ti me, select “SELF-DIAG RESULTS”. In
case a 1st trip DTC other than P0735 is shown, refer to “ TM-117, "DTC No. Index"
”.
If “COMPLETED RESULT NG” is detected, go to TM-63, "Diagnosis Procedure"
.
If “STOP VEHICLE” is detect ed, go to the following step.
6. Stop vehicle.
7. Drive vehicle in “D” position allowing it to shif t from 1GR to 5GR gear and check shift timing and shift
shock.
- Touch “OK” to complete the inspection when normally shifted from the 1GR to 5GR.
- Touch “NG” when an unusual shift shock, etc. occurs in spite of shifting from the 1GR to 5GR. Go to TM-
190, "Description".
- Perform TM-32, "CONSULT-III Function (TRANSMISSION)"
when not shifted from the 1GR to 5GR. (Nei-
ther “OK” nor “NG” are indicated.)
Revision: December 20092009 QX56

TM-66
< COMPONENT DIAGNOSIS >
P0744 TORQUE CONVERTER
P0744 TORQUE CONVERTER
DescriptionINFOID:0000000003771896
This malfunction is detected when the A/T does not lock-up. This is not only caused by electrical malfunction
(circuits open or shorted) but also by mechanical malfunc tion such as control valve sticking, improper solenoid
valve operation, etc.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000003771897
On Board Diagn osis LogicINFOID:0000000003771898
 This is an OBD-II self-diagnostic item.
 Diagnostic trouble code “P0744” with CONSULT-III is detected under the following conditions.
- When A/T cannot perform lock-up even if electrical circuit is good.
- When TCM detects as irregular by comparing difference value with slip rotation.
Possible CauseINFOID:0000000003771899
 Harness or connectors
(The solenoid circuit is open or shorted.)
 Torque converter clutch solenoid valve
 Hydraulic control circuit
DTC Confirmation ProcedureINFOID:0000000003771900
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch “OFF”
and wait at least 10 seconds before performing the next test.
After the repair, perform the following proc edure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Start engine and Select “TCC S/V FNCTN CHECK” of “DTC WORK SUPPORT” mode for “TRANSMIS-
SION” with CONSULT-III and touch “START”.
2. Accelerate vehicle to more than 80 km/h (50 MPH) and maintain the following condition continuously until “TESTING” has turned to “COMPLETE”. (It will take approximately 30 seconds after “TESTING” shows.)
ACCELE POSI: More than 1.0/8 (at all times during step 4)
TCC SOLENOID: 0.4 - 0.6 A
SLCT LVR POSI: “D” position
[Reference speed: Constant speed of more than 80 km/h (50 MPH)]
- Make sure “GEAR” shows “5”.
- For shift schedule, refer to TM-291, "Vehicle Speed at Which Lock-up Occurs/Releases"
.
- If “TESTING” does not ap pear on CONSULT-III for a long ti me, select “SELF-DIAG RESULTS”. In
case a 1st trip DTC other than P0744 is shown, refer to applicable “TROUBLE DIAGNOSIS FOR
DTC”.
3. Make sure that “OK” is displayed. (If “NG” is displayed, refer to “DIAGNOSTIC PROCEDURE”.)
Refer to TM-67, "Diagnosis Procedure"
.
Refer to shift schedule, TM-291, "Vehicle Speed at Which Lock-up Occurs/Releases"
.
WITH GST
Follow the procedure “With CONSULT-III”.
Item name Condition Display value (Approx.)
TCC SOLENOID When performing slip lock-up 0.2 - 0.4 A
When performing lock-up 0.4 - 0.6 A
Revision: December 20092009 QX56

TM-70
< COMPONENT DIAGNOSIS >
P1705 TP SENSOR
P1705 TP SENSOR
DescriptionINFOID:0000000003771908
Electric throttle control actuator consists of throttle control motor, accelerator pedal position sensor, throttle
position sensor, etc. The actuator sends a signal to the ECM, and ECM sends signals to TCM with CAN com-
munication.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000003771909
On Board Diagn osis LogicINFOID:0000000003771910
 This is not an OBD-II self-diagnostic item.
 Diagnostic trouble code “P1705” with CONSULT-III is detected when TCM does not receive the proper
accelerator pedal position signals (input by CAN communication) from ECM.
Possible CauseINFOID:0000000003771911
Harness or connectors
(The sensor circuit is open or shorted.)
DTC Confirmation ProcedureINFOID:0000000003771912
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch “OFF”
and wait at least 10 seconds before performing the next test.
After the repair, perform the following proc edure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “DATA MONITOR” mode for “TRANSMISSION” with CONSULT-III.
3. Start engine and let it idle for 1 second.
4. If DTC is detected, go to TM-70, "Diagnosis Procedure"
.
Diagnosis ProcedureINFOID:0000000003771913
1.CHECK CAN COMMUNICATION LINE
Perform the self-diagnosis. Refer to TM-32, "CONSULT-III Function (TRANSMISSION)"
.
Is a malfunction in the CAN communication indicated in the results?
YES >> Check CAN communication line. Refer to TM-39.
NO >> GO TO 2.
2.CHECK DTC WITH TCM
With CONSULT-III
1. Turn ignition switch “ON”. (Do not start engine.)
2. Select “ECU INPUT SIGNALS” in “DATA MONI TOR” mode for “TRANSMISSION” with CONSULT-III.
3. Depress accelerator pedal and read out the value of “ACCELE POSI”.
4. Select “SELF-DIAG RESULTS” mode for “T RANSMISSION” with CONSULT-III. Refer to TM-32, "CON-
SULT-III Function (TRANSMISSION)".
Item name Condition Display value (Approx.)
ACCELE POSIReleased accelerator pedal. 0.0/8
Fully depressed accelerator pedal. 8/8
Item name Condition
Display value
(Approx.)
ACCELE POSI Released accelerator pedal. 0.0/8
Fully depressed accelerator pedal. 8/8
Revision: December 20092009 QX56

TM-90
< COMPONENT DIAGNOSIS >
P1774 LOW COAST BRAKE SOLENOID
P1774 LOW COAST BRAKE SOLENOID
DescriptionINFOID:0000000003771969
 Low coast brake solenoid valve is turned “ON” or “OFF” by the TCM in response to signals sent from the
transmission range switch, output speed sensor and accele rator pedal position sensor (throttle position sen-
sor). Gears will then be shifted to the optimum position.
 This is not only caused by electrical malfunction (cir cuits open or shorted) but also by mechanical malfunc-
tion such as control valve sticking, improper solenoid valve operation.
CONSULT-III Reference Value in Data Monitor ModeINFOID:0000000003771970
On Board Diagn osis LogicINFOID:0000000003771971
 This is an OBD-II self-diagnostic item.
 Diagnostic trouble code “P1774” with CONSULT-III is detected under the following conditions.
- When TCM detects that actual gear ratio is irr egular, and relation between gear position and condition of
ATF pressure switch 2 is irregular during depressing accelerator pedal. (Other than during shift change)
- When TCM detects that relation between gear position and condition of ATF pressure switch 2 is irregular
during releasing accelerator pedal. (Other than during shift change)
Possible CauseINFOID:0000000003771972
 Harness or connectors
(The solenoid and switch circuits are open or shorted.)
 Low coast brake solenoid valve
 ATF pressure switch 2
DTC Confirmation ProcedureINFOID:0000000003771973
CAUTION:
Always drive vehicle at a safe speed.
NOTE:
If “DTC Confirmation Procedure” has been previously performed, always turn ignition switch “OFF”
and wait at least 10 seconds before performing the next test.
After the repair, perform the following proc edure to confirm the malfunction is eliminated.
WITH CONSULT-III
1. Start engine.
2. Accelerate vehicle to maintain the following conditions.
SLCT LVR POSI: “1” or “2” position
GEAR: “1st” or “2nd” (LC/B ON/OFF)
3. Perform step “2” again.
4. Turn ignition switch “OFF”, then perform step “1” to “3” again.
5. Check “SELF-DIAG RESULTS” mode for “TRANS MISSION” with CONSULT-III. If DTC (P1774) is
detected, refer to TM-90, "Diagnosis Procedure"
.
If DTC (P1772) is detected, go to TM-88, "Diagnosis Procedure"
.
WITH GST
Follow the procedure “With CONSULT-III”.
Diagnosis ProcedureINFOID:0000000003771974
1.CHECK INPUT SIGNALS
Item name Condition Display value
ON OFF SOLLow coast brake engaged. Refer to
TM-9
ON
Low coast brake disengaged. Refer to TM-9
OFF
ATF PRES SW 2 Low coast brake engaged. Refer to
TM-9
ON
Low coast brake disengaged. Refer to TM-9
OFF
Revision: December 20092009 QX56

TM-104
< ECU DIAGNOSIS >
TCM
ECU DIAGNOSIS
TCM
Reference ValueINFOID:0000000003771985
REFERENCE VALUES
NOTICE:
1. The CONSULT-III electrically displays shift timing and lock-up timing (that is, operation timing of each
solenoid).
Check for time difference between actual shift timi ng and the CONSULT-III display. If the difference is
noticeable, mechanical parts (except solenoids, sens ors, etc.) may be malfunctioning. Check mechanical
parts using applicable diagnostic procedures.
2. Shift schedule (which implies gear position) display ed on CONSULT-III and that indicated in Service Man-
ual may differ slightly. This occurs because of the following reasons:
- Actual shift schedule has more or less tolerance or allowance,
- Shift schedule indicated in Service Manual refers to the point where shifts start, and
- Gear position displayed on CONSULT-III indicates the point where shifts are completed.
3. Display of solenoid valves on CONSULT-III changes at t he start of shifting, while gear position is displayed
upon completion of shifting (which is computed by TCM).
Item name Condition Display value (Approx.)
AT F T E M P S E 1 0 °C (32 ° F) - 20 °C (68 °F) - 80 °C (176 °F) 3.3 - 2.7 - 0.9 V
TCC SOLENOID When perform slip lock-up 0.2 - 0.4 A
When perform lock-up 0.4 - 0.6 A
SLCT LVR POSI Selector lever in “N”,“P” position. N/P
Selector lever in “R” position. R
Selector lever in “D” position. D
Selector lever in “4” position. 4
Selector lever in “3” position. 3
Selector lever in “2” position. 2
Selector lever in “1” position. 1
VHCL/S SE·A/T During driving Approximately matches the
speedometer reading.
ENGINE SPEED Engine running Closely matches the tachometer
reading.
LINE PRES SOL During driving 0.2 - 0.6 A
INPUT SPEED During driving (lock-up ON) Approximately matches the en-
gine speed.
VHCL/S SE·MTR During driving Approximately matches the
speedometer reading.
ATF PRES SW 2 Low coast brake engaged. Refer to
TM-9
ON
Low coast brake disengaged. Refer to TM-9
OFF
I/C SOLENOID Input clutch disengaged. Refer to
TM-9
0.6 - 0.8 A
Input clutch engaged. Refer to TM-9
0 - 0.05 A
FR/B SOLENOID Front brake engaged. Refer to
TM-9
0.6 - 0.8 A
Front brake disengaged. Refer to TM-9
0 - 0.05 A
D/C SOLENOID Direct clutch disengaged. Refer to
TM-9
0.6 - 0.8 A
Direct clutch engaged. Refer to TM-9
0 - 0.05 A
HLR/C SOL High and low reverse clutch disengaged. Refer to
TM-9
0.6 - 0.8 A
High and low reverse clutch engaged. Refer to TM-9
0 - 0.05 A
Revision: December 20092009 QX56

TCM
TM-115
< ECU DIAGNOSIS >
C EF
G H
I
J
K L
M A
B
TM
N
O P
Fail-SafeINFOID:0000000003771987
The TCM has an electrical fail-safe mode. This mode make s it possible to operate even if there is an error in a
main electronic control input/output signal circuit.
The TCM has an electrical fail-safe mode. This mode make s it possible to operate even if there is an error in a
main electronic control input/output signal circuit. In fa il-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”.
ABDIA0053GB
Revision: December 20092009 QX56

TM-116
< ECU DIAGNOSIS >
TCM
Even when the electronic circuits are normal, under special conditions (for example, when slamming on the
brake with the wheels spinning drastically and stopping t he 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 v ehicle has returned to normal, so handle according to the
“diagnostics flow” (Refer to TM-5, "Work Flow"
).
FAIL-SAFE FUNCTION
If any malfunction occurs in a sensor or solenoid, th is function controls the A/T to mark driving possible.
Output Speed Sensor
 Signals are input from two systems - from output s peed sensor installed on the transmission and from com-
bination meter so normal driving is possible even if ther e is a malfunction in one of the systems. And if output
speed sensor has unusual cases, 5GR is prohibited.
Accelerator Peda l 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.
Transmission Range Switch
 In the unlikely event that a malfunction signal enters t he 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.)
Interlock
 If there is an interlock judgment malfunction, the trans mission is fixed in 2GR to make driving possible.
NOTE:
When the vehicle is driven fixed in 2GR, a input speed sensor malfunction is displayed, but this is
not a input speed sensor malfunction.
 When the interlock is detected at the 3GR or more, it is locked at the 2GR.
1st Engine Braking
 When there is an 1st gear engine brake judgment malfunc tion, the low coast brake solenoid is switched
“OFF” to avoid the engine brake operation.
Line Pressure Solenoid
 The solenoid is switched “OFF” and the line pressure is se t to the maximum hydraulic pressure to make driv-
ing possible.
Torque Converter Clutch Solenoid
 The solenoid is switched “OFF” to release the lock-up.
Low Coast Brake Solenoid
 When a (electrical or functional) malfunction occurs, in order to make driving possible, the engine brake is not applied in 1GR and 2GR.
Input Clutch Solenoid
 If a (electrical or functional) malfunction occurs with the solenoid either “ON” or “OFF”, the transmission is
held in 4GR to make driving possible.
Direct Clutch Solenoid
 If a (electrical or functional) malfunction occurs with the solenoid either “ON” or “OFF”, the transmission is
held in 4GR to make driving possible.
Front Brake Solenoid
 If a (electrical or functional) malfunction occurs with the solenoid “ON”, in order to make driving possible, the
A/T is held in 5GR; if the solenoid is OFF, 4GR.
Revision: December 20092009 QX56