Ins INFINITI QX56 2004 Factory Workshop Manual

TROUBLE DIAGNOSIS
AT-63
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
4. CHECK “N” POSITION FUNCTIONS
1. Start the engine.
2. Move selector lever to “N” position.
3. Release the parking brake.
Does vehicle move forward or backward?
YES >> Enter a check mark at “Vehicle moves in “N” position” on the diagnostics worksheet, then continue
the road test.
NO >> GO TO 5.
5. CHECK SHIFT SHOCK
1. Engage the brake.
2. Move selector lever to “D” position.
When the transmission is shifted from
“N” to “D”, is there an excessive shock?
YES >> Enter a check mark at “Large shock when shifted from N to D” on the diagnostics worksheet, then
continue the road test.
NO >> GO TO 6.
6. CHECK “R” POSITION FUNCTIONS
1. Engage the brake.
2. Move selector lever to “R” position.
3. Disengage the brake for 4 to 5 seconds.
Does the vehicle creep backward?
YES >> GO TO 7.
NO >> Enter a check mark at “Vehicle does not creep backward in R position” on the diagnostics work-
sheet, then continue the road test.
7. CHECK “D” POSITION FUNCTIONS
Inspect whether the vehicle moves forward when the transmission is put into the “D” position.
Does the vehicle creep forward in the
“D” positions?
YES >> Go to AT- 6 3 , "Cruise Test - Part 1" , AT- 6 5 , "Cruise Test - Part 2" , and AT- 6 6 , "Cruise Test - Part
3" .
NO >> Enter a check mark at “Vehicle does not move forward in D positions” on the diagnostics work-
sheet, then continue the road test.
Cruise Test - Part 1UCS002D0
1. CHECK STARTING OUT FROM D1
1. Drive the vehicle for about 10 minutes to warm up the engine oil and ATF.
Appropriate temperature for the ATF: 50 - 80°C (122 - 176°F)
2. Park the vehicle on a level surface.
3. Move selector lever to “P” position.
4. Start the engine.
5. Move selector lever to “D” position.
6. Press the accelerator pedal about half way down to accelerate the vehicle.
With CONSULT-II
Read off the gear positions.
Starts from D1?
YES >> GO TO 2.
NO >> Enter a check mark at “Vehicle cannot be started from D1” on the diagnostics worksheet, then
continue the road test.

AT-64
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
2. CHECK SHIFT-UP D1 → D2
Press down the accelerator pedal about half way and inspect if the vehicle shifts up (D1 → D2) at the appropri-
ate speed.

Refer to AT-67, "Vehicle Speed When Shifting Gears" .
With CONSULT-II
Read the gear position, throttle degree of opening, and vehicle speed.
Does the A/T shift-up D1
→ D2 at the correct speed?
YES >> GO TO 3.
NO >> Enter a check mark at “A/T does not shift D1 → D2” on the diagnostics worksheet, then continue
the road test.
3. CHECK SHIFT-UP D2 → D3
Press down the accelerator pedal about half way and inspect if the vehicle shifts up (D2 → D3) at the appropri-
ate speed.

Refer to AT-67, "Vehicle Speed When Shifting Gears" .
With CONSULT-II
Read the gear position, throttle degree of opening, and vehicle speed.
Does the A/T shift-up D2
→ D3 at the correct speed?
YES >> GO TO 4.
NO >> Enter a check mark at “A/T does not shift D2 → D3” on the diagnostics worksheet, then continue
the road test.
4. CHECK SHIFT-UP D3 → D4
Press down the accelerator pedal about half way and inspect if the vehicle shifts up (D3 → D4) at the appropri-
ate speed.

Refer to AT-67, "Vehicle Speed When Shifting Gears" .
With CONSULT-II
Read the gear position, throttle degree of opening, and vehicle speed.
Does the A/T shift-up D3
→ D4 at the correct speed?
YES >> GO TO 5.
NO >> Enter a check mark at “A/T does not shift D3 → D4” on the diagnostics worksheet, then continue
the road test.
5. CHECK SHIFT-UP D4 → D5
Press down the accelerator pedal about half way and inspect if the vehicle shifts up (D4 → D5) at the appropri-
ate speed.

Refer to AT-67, "Vehicle Speed When Shifting Gears" .
With CONSULT-II
Read the gear position, throttle degree of opening, and vehicle speed.
Does the A/T shift-up D4
→ D5 at the correct speed?
YES >> GO TO 6.
NO >> Enter a check mark at “A/T does not shift D4 → D5” on the diagnostics worksheet, then continue
the road test.

AT-66
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
2. CHECK SHIFT-UP D1 → D2
Press the accelerator pedal down all the way and inspect whether or not the transmission shifts up (D1 → D2)
at the correct speed.

Refer to AT-67, "Vehicle Speed When Shifting Gears" .
With CONSULT-II
Read the gear position, throttle position and vehicle speed.
Does the A/T shift-up D1
→ D2 at the correct speed?
YES >> GO TO 3.
NO >> Enter a check mark at “Vehicle does not shift D1 → D2” on the diagnostics worksheet, then con-
tinue the road test.
3. CHECK SHIFT-UP D2 → D3
Press the accelerator pedal down all the way and inspect whether or not the transmission shifts up (D2 → D3)
at the correct speed.

Refer to AT-67, "Vehicle Speed When Shifting Gears" .
With CONSULT-II
Read the gear position, throttle position and vehicle speed.
Does the A/T shift-up D2
→ D3 at the correct speed?
YES >> GO TO 4.
NO >> Enter a check mark at “Vehicle does not shift D2 → D3” on the diagnostics worksheet, then con-
tinue the road test.
4. CHECK SHIFT-UP D3 → D4 AND ENGINE BRAKE
When the transmission changes speed D3 → D4, return the accelerator pedal.
Does the A/T shift-up D3
→ D4 and apply the engine brake?
YES >> 1. Stop the vehicle.
2. See AT-66, "
Cruise Test - Part 3" .
NO >> Enter a check mark at “Vehicle does not shift D3 → D4” on the diagnostics worksheet, then con-
tinue the road test.
Cruise Test - Part 3UCS002D2
1. CHECK SHIFT-DOWN
During D
5 driving, move gear selector from D → 4 → 3 → 2 → 1.
With CONSULT-II
Read the gear position.
Is downshifting correctly performed?
YES >> GO TO 2.
NO >> Enter a check mark at “Vehicle does not shift” at the corresponding position (5th → 4th, 4th → 3rd,
3rd → 2nd, 2nd → 1st) on the diagnostics worksheet, then continue the road test.
2. CHECK ENGINE BRAKE
Does engine braking effectively reduce speed in 1
1 position?
YES >> 1. Stop the vehicle.
2. Carry out the self-diagnostics. Refer to AT-93, "
SELF-DIAGNOSTIC RESULT MODE" .
NO >> Enter a check mark at “Vehicle does not decelerate by engine brake” on the diagnostics work-
sheet, then continue trouble diagnosis.

AT-68
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
Symptom ChartUCS002D6

The diagnostics item numbers show the sequence for inspection. Inspect in order from item 1.

Overhaul and inspect inside the A/T only if A/T fluid condition is NG. Refer to AT-58, "Fluid Condi-
tion Check" .
No. Items Symptom Condition Diagnostic ItemReference
page
1
Shift
ShockLarge shock. (“N” →“
D” position)
Refer to AT-195,
"Large Shock (“N” to
“D” Position)" .ON vehicle1. Engine idle speedEC-32
2. Engine speed signalAT - 11 5
3. Accelerator pedal position sensorAT- 1 2 9
4. Control cable adjustmentAT- 2 3 4
5. ATF temperature sensorAT- 1 3 1
6. ATF pressure switch 1 and front brake solenoid valveAT- 1 7 5,
AT- 1 5 1
7. CAN communication lineAT- 1 0 3
8. Fluid level and stateAT-5 8
9. Line pressure testAT-5 9
10. Control valve with TCMAT- 2 4 2
OFF vehicle11. 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
2Shock is too large
when changing D1 →
D
2 .ON vehicle1. Accelerator pedal position sensorAT- 1 2 9
2. Control cable adjustmentAT- 2 3 4
3. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 8 1,
AT- 1 5 7
4. CAN communication lineAT- 1 0 3
5. Engine speed signalAT - 11 5
6. Turbine revolution sensorAT- 1 3 4
7. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 2,
AT- 1 3 6
8. Fluid level and stateAT-5 8
9. Control valve with TCMAT- 2 4 1
OFF vehicle 10. Direct clutchAT- 3 0 7
3Shock is too large
when changing D2 →
D
3 .ON vehicle1. Accelerator pedal position sensorAT- 1 2 9
2. Control cable adjustmentAT- 2 3 4
3. ATF pressure switch 6, high and low reverse clutch sole-
noid valveAT- 1 8 4,
AT- 1 6 3
4. CAN communication lineAT- 1 0 3
5. Engine speed signalAT - 11 5
6. Turbine revolution sensorAT- 1 3 4
7. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 2,
AT- 1 3 6
8. Fluid level and stateAT-5 8
9. Control valve with TCMAT- 2 4 1
OFF vehicle 10. High and low reverse clutchAT- 3 0 5

TROUBLE DIAGNOSIS
AT-73
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
18
Slips/Will
Not
engageWhen “D” position,
remains in 1st gear.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. Direct clutch solenoid valveAT- 1 5 7
4. Line pressure testAT- 5 9
5. CAN communication lineAT- 1 0 3
6. Control valve with TCMAT- 2 4 1
OFF vehicle7. 3rd one-way clutchAT- 2 9 2
8. 1st one-way clutchAT- 3 0 0
9. Gear systemAT- 2 6 1
10. Reverse brakeAT- 2 7 3
11. 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
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
19When “D” position,
remains in 2nd gear.ON vehicle1. Fluid level and stateAT- 5 8
2. Vehicle speed sensor A/T and vehicle speed sensor MTR AT- 11 2 ,
AT- 1 3 6
3. Low coast brake solenoid valveAT- 1 6 9
4. Line pressure testAT- 5 9
5. CAN communication lineAT- 1 0 3
6. Control valve with TCMAT- 2 4 1
OFF vehicle7. 3rd one-way clutchAT- 2 9 2
8. Gear systemAT- 2 6 1
9. Direct clutchAT- 3 0 7
10. 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-74
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
20
Slips/Will
Not
engageWhen “D” position,
remains in 3rd gear.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. Line pressure testAT-5 9
4. CAN communication lineAT- 1 0 3
5. Control valve with TCMAT- 2 4 1
OFF vehicle6. 3rd one-way clutchAT- 2 9 2
7. Gear systemAT- 2 6 1
8. High and low reverse clutchAT- 3 0 5
9. 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
10. 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
21When “D” position,
remains in 4th gear.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 5 and direct clutch solenoid valveAT-181,AT-
157
5. ATF pressure switch 6, high and low reverse clutch sole-
noid valveAT- 1 8 4
,
AT- 1 6 3
6. Low coast brake solenoid valveAT- 1 6 9
7. Front brake solenoid valveAT- 1 5 1
8. Line pressure testAT-5 9
9. CAN communication lineAT- 1 0 3
10. Control valve with TCMAT- 2 4 1
OFF vehicle11. Input clutchAT- 2 9 512. Gear systemAT- 2 6 1
13. High and low reverse clutchAT- 3 0 5
14. Direct clutchAT- 3 0 7
No. Items Symptom Condition Diagnostic ItemReference
page

TROUBLE DIAGNOSIS
AT-75
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
22
Slips/Will
Not
EngageWhen “D” position,
remains in 5th gear.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. Line pressure testAT- 5 9
5. CAN communication lineAT- 1 0 3
6. Control valve with TCMAT- 2 4 1
OFF vehicle7. Front brake (brake band)AT- 2 7 38. Input clutchAT- 2 9 5
9. Gear systemAT- 2 6 1
10. High and low reverse clutchAT- 3 0 5
23Vehicle cannot be
started from D
1 .
Refer toAT- 2 0 3 , "
Vehi-
cle Cannot Be Started
From D1" .ON vehicle1. Fluid level and stateAT- 5 8
2. Accelerator pedal position sensorAT- 1 2 9
3. Line pressure testAT- 5 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
24Does not lock-up.
Refer to AT- 2 1 5 , "A/T
Does Not Perform
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
No. Items Symptom Condition Diagnostic ItemReference
page

AT-76
TROUBLE DIAGNOSIS
Revision: August 20072004 QX56
25
Slips/Will
Not
engageDoes not hold lock-up
condition.
Refer toAT- 2 1 7 , "A/T
Does Not Hold Lock-
up Condition" .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
26Lock-up is not
released.
Refer toAT- 2 1 9 ,
"Lock-up Is Not
Released" .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
27No shock at all or the
clutch slips when
vehicle changes
speed D
1 → D2 . 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 5 and direct clutch solenoid valveAT- 1 8 1,
AT- 1 5 7
4. CAN communication lineAT- 1 0 3
5. Line pressure testAT-5 9
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

TROUBLE DIAGNOSIS
AT-77
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: August 20072004 QX56
28
Slips/Will
Not
engageNo shock at all or the
clutch slips when
vehicle changes
speed D
2 → D3 .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. CAN communication lineAT- 1 0 3
5. Line pressure testAT- 5 9
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
29No shock at all or the
clutch slips when
vehicle changes
speed D
3 → D4 .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 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