low oil pressure INFINITI QX56 2004 Factory User Guide

AT-78
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
30
Slips/Will
Not
engageNo shock at all or the
clutch slips when
vehicle changes
speed D
4 → D5 .ON vehicle1. Fluid level and stateAT-5 8
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 2,
AT- 1 3 6
3. ATF pressure switch 1 and front brake solenoid valveAT- 1 7 5,
AT- 1 5 1
4. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 8 1,
AT- 1 5 7
5. CAN communication lineAT- 1 0 3
6. Line pressure testAT-5 9
7. Control valve with TCMAT- 2 4 1
OFF vehicle8. Torque converterAT- 2 7 3
9. Oil pump assemblyAT- 2 9 0
10. Front brake (brake band)AT- 2 7 3
11. Input clutchAT- 2 9 5
12. Gear systemAT- 2 6 1
13. High and low reverse clutchAT- 3 0 5
31When you press the
accelerator pedal and
shift speed D5 → D4
the engine idles or the
transmission slips.ON vehicle1. Fluid level and stateAT-5 8
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 2,
AT- 1 3 6
3. ATF pressure switch 1 and front brake solenoid valveAT- 1 7 5,
AT- 1 5 1
4. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 8 1,
AT- 1 5 7
5. CAN communication lineAT- 1 0 3
6. Line pressure testAT-5 9
7. Control valve with TCMAT- 2 4 1
OFF vehicle8. Torque converterAT- 2 7 3
9. Oil pump assemblyAT- 2 9 0
10. Input clutchAT- 2 9 5
11. Gear systemAT- 2 6 1
12. High and low reverse clutchAT- 3 0 5
13. Direct clutchAT- 3 0 7
No. Items Symptom Condition Diagnostic ItemReference
page

TROUBLE DIAGNOSIS
AT-79
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
32
Slips/Will
Not
engageWhen you press the
accelerator pedal and
shift speed D4 → D3
the engine idles or the
transmission slips.ON vehicle1. Fluid level and stateAT- 5 8
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 2,
AT- 1 3 6
3. ATF pressure switch 3 and input clutch solenoid valveAT- 1 7 8,
AT- 1 4 5
4. ATF pressure switch 1 and front brake solenoid valveAT- 1 7 5,
AT- 1 5 1
5. CAN communication lineAT- 1 0 3
6. Line pressure testAT- 5 9
7. Control valve with TCMAT- 2 4 1
OFF vehicle8. Torque converter AT- 2 7 3
9. Oil pump assemblyAT- 2 9 0
10. 3rd one-way clutchAT- 2 9 2
11. Gear systemAT- 2 6 1
12. High and low reverse clutchAT- 3 0 5
13. Forward one- way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT- 1 8
, AT-1 9 .)AT- 2 7 3
14. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-1 8
, AT - 1 9
.)AT- 2 7 3
33When you press the
accelerator pedal and
shift speed D3 → D2
the engine idles or the
transmission slips.ON vehicle1. Fluid level and stateAT- 5 8
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 2,
AT- 1 3 6
3. ATF pressure switch 6, high and low reverse clutch sole-
noid valveAT- 1 8 4,
AT- 1 6 3
4. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 8 1,
AT- 1 5 7
5. CAN communication lineAT- 1 0 3
6. Line pressure testAT- 5 9
7. Control valve with TCMAT- 2 4 1
OFF vehicle8. Torque converterAT- 2 7 3
9. Oil pump assemblyAT- 2 9 0
10. 3rd one-way clutchAT- 2 9 2
11. Gear systemAT- 2 6 1
12. Direct clutchAT- 3 0 7
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-1 8
, AT - 1 9
.)AT- 2 7 3
No. Items Symptom Condition Diagnostic ItemReference
page

TROUBLE DIAGNOSIS
AT-81
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
36
Slips/Will
Not
EngageWith selector lever in
“R” position, accelera-
tion is extremely poor.ON vehicle1. Fluid level and stateAT- 5 8
2. Line pressure testAT- 5 9
3. Accelerator pedal position sensorAT- 1 2 9
4. ATF pressure switch 6, high and low reverse clutch sole-
noid valveAT- 1 8 4,
AT- 1 6 3
5. CAN communication lineAT- 1 0 3
6. PNP switchAT- 1 0 9
7. Control cable adjustmentAT- 2 3 4
8. Control valve with TCMAT- 2 4 1
OFF vehicle9. Gear systemAT- 2 6 110. Output shaftAT- 2 7 3
11. Reverse brakeAT- 2 7 3
37While starting off by
accelerating in 1st,
engine races or slip-
page occurs.ON vehicle1. Fluid level and stateAT- 5 8
2. Line pressure testAT- 5 9
3. Accelerator pedal position sensorAT- 1 2 9
4. CAN communication lineAT- 1 0 3
5. Control valve with TCMAT- 2 4 1
OFF vehicle6. Torque converterAT- 2 7 3
7. Oil pump assemblyAT- 2 9 0
8. 3rd one-way clutchAT- 2 9 2
9. 1st one-way clutchAT- 3 0 0
10. Gear systemAT- 2 6 1
11. Reverse brakeAT- 2 7 3
12. Forward one- way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT- 1 8
, AT-1 9 .)AT- 2 7 3
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-1 8
, AT - 1 9
.)AT- 2 7 3
38While accelerating in
2nd, engine races or
slippage occurs.ON vehicle1. Fluid level and stateAT- 5 8
2. Line pressure testAT- 5 9
3. Accelerator pedal position sensorAT- 1 2 9
4. CAN communication lineAT- 1 0 3
5. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 8 1,
AT- 1 5 7
6. Control valve with TCMAT- 2 4 1
OFF vehicle7. Torque converterAT- 2 7 3
8. Oil pump assemblyAT- 2 9 0
9. 3rd one-way clutchAT- 2 9 2
10. Gear systemAT- 2 6 1
11. Direct clutchAT- 3 0 7
12. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-1 8
, AT - 1 9
.)AT- 2 7 3
No. Items Symptom Condition Diagnostic ItemReference
page

AT-82
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
39
Slips/Will
Not
EngageWhile accelerating in
3rd, engine races or
slippage occurs.ON vehicle1. Fluid level and stateAT-5 8
2. Line pressure testAT-5 9
3. Accelerator pedal position sensorAT- 1 2 9
4. CAN communication lineAT- 1 0 3
5. ATF pressure switch 6, high and low reverse clutch sole-
noid valveAT- 1 8 4,
AT- 1 6 3

6. Control valve with TCMAT- 2 4 1
OFF vehicle7. Torque converterAT- 2 7 3
8. Oil pump assemblyAT- 2 9 0
9. 3rd one-way clutchAT- 2 9 2
10. Gear systemAT- 2 6 1
11. High and low reverse clutchAT- 3 0 5
12. Forward one- way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT-1 8
, AT- 1 9 .)AT- 2 7 3
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT- 1 8
, AT- 1 9
.)AT- 2 7 3
40While accelerating in
4th, engine races or
slippage occurs.ON vehicle1. Fluid level and stateAT-5 8
2. Line pressure testAT-5 9
3. Accelerator pedal position sensorAT- 1 2 9
4. CAN communication lineAT- 1 0 3
5. ATF pressure switch 3 and input clutch solenoid valveAT- 1 7 8,
AT- 1 4 5
6. Control valve with TCMAT- 2 4 1
OFF vehicle7. Torque converterAT- 2 7 3
8. Oil pump assemblyAT- 2 9 0
9. Input clutchAT- 2 9 5
10. Gear systemAT- 2 6 1
11. High and low reverse clutchAT- 3 0 5
12. Direct clutchAT- 3 0 7
No. Items Symptom Condition Diagnostic ItemReference
page

TROUBLE DIAGNOSIS
AT-83
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
41
Slips/Will
Not
Engage While accelerating in
5th, engine races or
slippage occurs.ON vehicle1. Fluid level and stateAT- 5 8
2. Line pressure testAT- 5 9
3. Accelerator pedal position sensorAT- 1 2 9
4. CAN communication lineAT- 1 0 3
5. ATF pressure switch 1 and front brake solenoid valveAT- 1 7 5,
AT- 1 5 1
6. Control valve with TCMAT- 2 4 1
OFF vehicle7. Torque converterAT- 2 7 3
8. Oil pump assemblyAT- 2 9 0
9. Front brake (brake band)AT- 2 7 3
10. Input clutchAT- 2 9 5
11. Gear systemAT- 2 6 1
12. High and low reverse clutchAT- 3 0 5
42 Slips at lock-up.ON vehicle1. Fluid level and stateAT- 5 8
2. Line pressure testAT- 5 9
3. Engine speed signalAT- 11 5
4. Turbine revolution sensorAT- 1 3 4
5. Torque converter clutch solenoid valveAT- 11 8
6. CAN communication lineAT- 1 0 3
7. Control valve with TCMAT- 2 4 1
OFF vehicle8. Torque converterAT- 2 7 39. Oil pump assemblyAT- 2 9 0
43No creep at all.
Refer toAT- 1 9 8 , "
Vehi-
cle Does Not Creep
Backward In “R” Posi-
tion" , AT-201, "Ve hi-
cle Does Not Creep
Forward In “D” Posi-
tion"
ON vehicle1. Fluid level and stateAT- 5 8
2. Line pressure testAT- 5 9
3. Accelerator pedal position sensorAT- 1 2 9
4. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 8 1,
AT- 1 5 7
5. PNP switchAT- 1 0 9
6. CAN communication lineAT- 1 0 3
7. Control cable adjustmentAT- 2 3 4
8. Control valve with TCMAT- 2 4 1
OFF vehicle9. Torque converterAT- 2 7 3
10. Oil pump assemblyAT- 2 9 0
11. 1st one-way clutchAT- 3 0 0
12. Gear systemAT- 2 6 1
13. Reverse brakeAT- 2 7 3
14. Direct clutchAT- 3 0 7
15. Forward one- way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT- 1 8
, AT-1 9 .)AT- 2 7 3
16. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-1 8
, AT - 1 9
.)AT- 2 7 3
No. Items Symptom Condition Diagnostic ItemReference
page

TROUBLE DIAGNOSIS
AT-87
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
56
OthersMaximum speed low.ON vehicle1. Fluid level and stateAT- 5 8
2. Line pressure testAT- 5 9
3. Accelerator pedal position sensorAT- 1 2 9
4. CAN communication lineAT- 1 0 3
5. Direct clutch solenoid valveAT- 1 5 7
6. Control valve with TCMAT- 2 4 1
OFF vehicle7. Torque converterAT- 2 7 3
8. Oil pump assemblyAT- 2 9 0
9. Input clutchAT- 2 9 5
10. Gear systemAT- 2 6 1
11. High and low reverse clutchAT- 3 0 5
12. Direct clutchAT- 3 0 7
13. Forward one- way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT- 1 8
, AT-1 9 .)AT- 2 7 3
14 Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-1 8
, AT - 1 9
.)AT- 2 7 3
57Extremely large
creep.ON vehicle1. Engine idle speed EC-32

2. CAN communication lineAT- 1 0 3
3. ATF pressure switch 5AT- 1 8 1
OFF vehicle 4. Torque converterAT- 2 7 3
58With selector lever in
“P” position, vehicle
does not enter parking
condition or, with
selector lever in
another position, park-
ing condition is not
cancelled.
Refer to AT- 1 9 3 , "
In
“P” Position, Vehicle
Moves When Pushed"
.ON vehicle1. PNP switchAT- 1 0 9
2. Control cable adjustmentAT- 2 3 4
3. Parking pawl componentsAT- 2 6 1
59Vehicle runs with
transmission in “P”
position.ON vehicle1. PNP switchAT- 1 0 9
2. Fluid level and stateAT- 5 8
3. Control cable adjustmentAT- 2 3 4
4. Control valve with TCMAT- 2 4 1
5. Parking pawl componentsAT- 2 6 1
OFF vehicle 6. Gear systemAT- 2 6 1
No. Items Symptom Condition Diagnostic ItemReference
page

AT-124
DTC P0745 LINE PRESSURE SOLENOID VALVE
Revision: August 20072004 QX56
DTC P0745 LINE PRESSURE SOLENOID VALVEPFP:31940
DescriptionUCS002EJ
The line pressure solenoid valve regulates the oil pump discharge pressure to suit the driving condition in
response to a signal sent from the TCM.
The line pressure duty cycle value is not consistent when the closed throttle position signal is “ON”.
To confirm the line pressure duty cycle at low pressure, the accelerator (throttle) should be open until
the closed throttle position signal is “OFF”.
CONSULT-II Reference ValueUCS002EK
On Board Diagnosis LogicUCS002EL

This is an OBD-II self-diagnostic item.

Diagnostic trouble code “L/PRESS SOL/CIRC” with CONSULT-II or P0745 without CONSULT-II is
detected under the following conditions.
–When TCM detects an improper voltage drop when it tries to operate the solenoid valve.
–When TCM detects as irregular by comparing target value with monitor value.
Possible CauseUCS002EM

Harness or connectors
(The solenoid circuit is open or shorted.)

Line pressure solenoid valve
DTC Confirmation ProcedureUCS002EN
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 procedure to confirm the malfunction is eliminated.
WITH CONSULT-II
1. Turn ignition switch “ON” and select “DATA MONITOR” mode for
“ENGINE” with CONSULT-II.
2. Engine start and wait at least 5 second.
3. If DTC is detected, go to AT-125, "
Diagnostic Procedure" .
WITH GST
Follow the procedure “With CONSULT-II”.
Item name Condition Display value (Approx.) (A)
LINE PRES SOL During driving 0.2 - 0.6
BCIA0030E

AT-196
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: August 20072004 QX56
4. CHECK A/T FLUID LEVEL
Check the A/T fluid level. Refer to AT-13, "
Checking A/T Fluid" .
OK or NG
OK >> GO TO 5.
NG >> Refill ATF.
5. CHECK LINE PRESSURE
Check line pressure at idle with selector lever in “D” position. Refer
to AT - 5 9 , "
LINE PRESSURE TEST" .
OK or NG
OK >> GO TO 8.
NG - 1 >> Line pressure high: GO TO 6.
NG - 2 >> Line pressure low: GO TO 7.
6. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT- 2 4 1 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT-273, "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-290, "Oil Pump" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace damaged parts.
7. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT- 2 4 1 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT-273, "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-290, "Oil Pump" .
–Power train system. Refer to AT-273, "Disassembly" .
–Transmission case. Refer to AT-273, "Disassembly" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace damaged parts.
SAT6 3 8A
SAT4 9 4G

TROUBLE DIAGNOSIS FOR SYMPTOMS
AT-199
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
5. DETECT MALFUNCTIONING ITEM
1. Disassemble A/T. Refer to AT- 2 7 3 , "
Disassembly" .
2. Check the following items:
–Reverse brake. Refer to AT-273, "Disassembly" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
6. CHECK LINE PRESSURE
Check the line pressure with the engine idling. Refer to AT-59, "
LINE
PRESSURE TEST" .
OK or NG
OK >> GO TO 9.
NG - 1 >> Line pressure high. GO TO 7.
NG - 2 >> Line pressure low. GO TO 8.
7. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT-241, "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT- 2 7 3 , "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-290, "Oil Pump" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
8. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT-241, "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT- 2 7 3 , "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-290, "Oil Pump" .
–Power train system. Refer to AT- 2 7 3 , "Disassembly" .
–Transmission case. Refer to AT - 2 7 3 , "Disassembly" .
OK or NG
OK >> GO TO 9.
NG >> Repair or replace damaged parts.
SAT4 9 4G

AT-202
TROUBLE DIAGNOSIS FOR SYMPTOMS
Revision: August 20072004 QX56
5. CHECK LINE PRESSURE
Check line pressure at idle with selector lever in “D” position. Refer
to AT - 5 9 , "
LINE PRESSURE TEST" .
OK or NG
OK >> GO TO 8.
NG - 1 >> Line pressure high. GO TO 6.
NG - 2 >> Line pressure low. GO TO 7.
6. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT- 2 4 1 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT-273, "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-290, "Oil Pump" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace damaged parts.
7. DETECT MALFUNCTIONING ITEM
1. Check control valve with TCM. Refer to AT- 2 4 1 , "
Control Valve With TCM and A/T Fluid Temperature Sen-
sor 2" .
2. Disassemble A/T. Refer to AT-273, "
Disassembly" .
3. Check the following items:
–Oil pump assembly. Refer to AT-290, "Oil Pump" .
–Power train system. Refer to AT-273, "Disassembly" .
–Transmission case. Refer to AT-273, "Disassembly" .
OK or NG
OK >> GO TO 8.
NG >> Repair or replace damaged parts.
8. CHECK A/T FLUID CONDITION
1. Remove oil pan. Refer to AT-241, "
Control Valve With TCM and A/T Fluid Temperature Sensor 2" .
2. Check A/T fluid condition. Refer to AT- 5 8 , "
Fluid Condition
Check" .
OK or NG
OK >> GO TO 9.
NG >> GO TO 12.
SAT4 9 4G
SCIA5199E