AT-40
TROUBLE DIAGNOSIS
Revision: 2006 November2007 350Z
TROUBLE DIAGNOSISPFP:00004
DTC Inspection Priority ChartNCS0001Z
If some DTCs are displayed at the same time, perform inspections one by one based on the following priority
chart.
NOTE:
If DTC “U1000 CAN COMM CIRCUIT” is displayed with other DTCs, first perform the trouble diagnosis
for “DTC U1000 CAN COMMUNICATION LINE”. Refer to AT- 9 4
.
Fail-safeNCS00020
The TCM has an electrical fail-safe mode. This mode makes it possible to operate even if there is a an error in
a main electronic control input/output signal circuit.
In fail-safe mode, even if the selector lever is “D” or “M” mode, the A/T 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 A/T 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 AT- 4 3 ,
"WORK FLOW" .
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 A/T
Signals are input from two systems - from vehicle speed sensor A/T (revolution sensor) installed on the A/T
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 and manual mode are 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 systems,
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 systems,
the accelerator opening angle is controlled by the idle signal sent from the ECM which is based on input indi-
cating 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” position to make driving possible.
Starter Relay
The starter relay is switched OFF. (Starter starting is disabled.)
Priority Detected items (DTC)
1 U1000 CAN communication line
2 Except above
TROUBLE DIAGNOSIS
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A/T Interlock
If there is an A/T interlock judgment malfunction, the transmission is fixed in 2nd gear to make driving pos-
sible.
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 interlock is detected at the 3rd gear or more, it is locked at the 2nd gear.
A/T 1st Engine Braking
When there is an A/T first gear engine brake judgment malfunction, 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 set to the maximum hydraulic pressure to make driving
possible.
Torque Converter Clutch Solenoid
The solenoid is switched OFF to release the lock-up.
Low Coast Brake Solenoid
When a malfunction (electrical or functional) occurs, in order to make driving possible, if the solenoid is ON,
the A/T is held in 2nd gear; if the solenoid is OFF, the A/T is held in 4th gear. (Engine brake is not applied in
1st and 2nd gear.)
Input Clutch Solenoid
If a malfunction (electrical or functional) occurs with the solenoid either ON or OFF, the A/T is held in 4th gear
to make driving possible.
Direct Clutch Solenoid
If a malfunction (electrical or functional) occurs with the solenoid either ON or OFF, the A/T is held in 4th gear
to make driving possible.
Front Brake Solenoid
If a malfunction (electrical or functional) occurs with the solenoid ON, in order to make driving possible, the A/
T is held in 5th gear; if the solenoid is OFF, 4th gear.
High and Low Reverse Clutch Solenoid
If a malfunction (electrical or functional) occurs with the solenoid either ON or OFF, the A/T is held in 4th gear
to make driving possible.
Turbine Revolution Sensor 1 or 2
The control is the same as if there were no turbine revolution sensors, 5th gear and manual mode are prohib-
ited.
AT-42
TROUBLE DIAGNOSIS
Revision: 2006 November2007 350Z
How to Perform Trouble Diagnosis for Quick and Accurate RepairNCS00021
INTRODUCTION
The TCM receives a signal from the vehicle speed sensor, accelera-
tor pedal position sensor (throttle position sensor) or PNP switch and
provides shift control or lock-up control via A/T solenoid valves.
The TCM also communicates with the ECM by means of a signal
sent from sensing elements used with the OBD-related parts of the
A/T system for malfunction-diagnostic purposes. The TCM is capa-
ble of diagnosing malfunctioning parts while the ECM can store mal-
functions in its memory.
Input and output signals must always be correct and stable in the
operation of the A/T system. The A/T system must be in good oper-
ating condition and be free of valve seizure, solenoid valve malfunc-
tion, etc.
It is much more difficult to diagnose a error that occurs intermittently
rather than continuously. Most intermittent errors are caused by poor
electric connections or improper wiring. In this case, careful check-
ing of suspected circuits may help prevent the replacement of good
parts.
A visual check only may not find the cause of the errors. A road test
with CONSULT-III (or GST) or a circuit tester connected should be
performed. Follow the AT- 4 3 , "
WORK FLOW" .
Before undertaking actual checks, take a few minutes to talk with a
customer who approaches with a driveability complaint. The cus-
tomer can supply good information about such errors, especially
intermittent ones. Find out what symptoms are present and under
what conditions they occur. A “DIAGNOSTIC WORKSHEET” as
shown on the example (Refer to AT- 4 4
) should be used.
Start your diagnosis by looking for “conventional” errors first. This will
help troubleshoot driveability errors on an electronically controlled
engine vehicle.
Also check related Service bulletins.
SAT631IB
SAT632I
SEF234G
TROUBLE DIAGNOSIS
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Revision: 2006 November2007 350Z
4❏ Perform all road tests and enter checks in required inspection items.AT- 5 2
4-1.Check before engine is started AT- 5 3
❏ AT- 1 7 2 , "A/T Check Indicator Lamp Does Not Come On"
❏ Perform self-diagnostics. Enter checks for detected items. AT- 8 6 , AT- 9 2
❏ AT-94, "DTC U1000 CAN COMMUNICATION LINE"
❏ AT-97, "DTC P0615 START SIGNAL CIRCUIT"
❏ AT-101, "DTC P0700 TCM"
❏ AT-102, "DTC P0705 PARK/NEUTRAL POSITION SWITCH"
❏ AT-106, "DTC P0717 TURBINE REVOLUTION SENSOR"
❏ AT-108, "DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)"
❏ AT-113, "DTC P0725 ENGINE SPEED SIGNAL"
❏ AT-115, "DTC P0731 A/T 1ST GEAR FUNCTION"
❏ AT-117, "DTC P0732 A/T 2ND GEAR FUNCTION"
❏ AT-119, "DTC P0733 A/T 3RD GEAR FUNCTION"
❏ AT-121, "DTC P0734 A/T 4TH GEAR FUNCTION"
❏ AT-123, "DTC P0735 A/T 5TH GEAR FUNCTION"
❏ AT-125, "DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE"
❏ AT-127, "DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)"
❏ AT-129, "DTC P0745 LINE PRESSURE SOLENOID VALVE"
❏ AT-131, "DTC P1705 THROTTLE POSITION SENSOR"
❏ AT-134, "DTC P1710 A/T FLUID TEMPERATURE SENSOR CIRCUIT"
❏ AT-139, "DTC P1721 VEHICLE SPEED SENSOR MTR"
❏ AT-141, "DTC P1730 A/T INTERLOCK"
❏ AT-143, "DTC P1731 A/T 1ST ENGINE BRAKING"
❏ AT-145, "DTC P1752 INPUT CLUTCH SOLENOID VALVE"
❏ AT-147, "DTC P1757 FRONT BRAKE SOLENOID VALVE"
❏ AT-149, "DTC P1762 DIRECT CLUTCH SOLENOID VALVE"
❏ AT-151, "DTC P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE"
❏ AT-153, "DTC P1772 LOW COAST BRAKE SOLENOID VALVE"
❏ AT-155, "DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION"
❏ AT-157, "DTC P1815 MANUAL MODE SWITCH"
4-2.Check at IdleAT- 5 3
❏ AT- 1 7 3 , "Engine Cannot Be Started in “P” or “N” Position"
❏ AT- 1 7 3 , "In “P” Position, Vehicle Moves When Pushed"
❏ AT- 1 7 4 , "In “N” Position, Vehicle Moves"
❏ AT- 1 7 5 , "Large Shock (“N” to “D” Position)"
❏ AT- 1 7 7 , "Vehicle Does Not Creep Backward in “R” Position"
❏ AT- 1 7 9 , "Vehicle Does Not Creep Forward in “D” Position"
4-3.Cruise testAT- 5 5
Part 1
❏ AT- 1 8 1 , "
Vehicle Cannot Be Started from D1"
❏ AT- 1 8 3 , "A/T Does Not Shift: D1 → D2"
❏ AT- 1 8 5 , "A/T Does Not Shift: D2 → D3"
❏ AT- 1 8 7 , "A/T Does Not Shift: D3 → D4"
❏ AT- 1 8 9 , "A/T Does Not Shift: D4 → D5"
❏ AT- 1 9 1 , "A/T Does Not Lock-up"
❏ AT- 1 9 3 , "A/T Does Not Hold Lock-up Condition"
❏ AT- 1 9 4 , "Lock-up Is Not Released"
❏ AT- 1 9 5 , "Engine Speed Does Not Return to Idle"
AT-46
TROUBLE DIAGNOSIS
Revision: 2006 November2007 350Z
44-3.Part 2AT- 5 7
❏ AT-181, "Vehicle Cannot Be Started from D1"
❏ AT-183, "A/T Does Not Shift: D1 → D2"
❏ AT-185, "A/T Does Not Shift: D2 → D3"
❏ AT-187, "A/T Does Not Shift: D3 → D4"
Part 3AT- 5 8
❏ AT-196, "Cannot Be Changed to Manual Mode"
❏ AT-196, "A/T Does Not Shift: 5th Gear → 4th Gear"
❏ AT-198, "A/T Does Not Shift: 4th Gear → 3rd Gear"
❏ AT-199, "A/T Does Not Shift: 3rd Gear → 2nd Gear"
❏ AT-201, "A/T Does Not Shift: 2nd Gear → 1st Gear"
❏ AT-202, "Vehicle Does Not Decelerate by Engine Brake"
❏ Perform self-diagnostics. Enter checks for detected items. AT- 8 6 , AT- 9 2
❏ AT- 9 4 , "DTC U1000 CAN COMMUNICATION LINE"
❏ AT- 9 7 , "DTC P0615 START SIGNAL CIRCUIT"
❏ AT-101, "DTC P0700 TCM"
❏ AT-102, "DTC P0705 PARK/NEUTRAL POSITION SWITCH"
❏ AT-106, "DTC P0717 TURBINE REVOLUTION SENSOR"
❏ AT-108, "DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)"
❏ AT- 11 3 , "DTC P0725 ENGINE SPEED SIGNAL"
❏ AT- 11 5 , "DTC P0731 A/T 1ST GEAR FUNCTION"
❏ AT- 11 7 , "DTC P0732 A/T 2ND GEAR FUNCTION"
❏ AT- 11 9 , "DTC P0733 A/T 3RD GEAR FUNCTION"
❏ AT-121, "DTC P0734 A/T 4TH GEAR FUNCTION"
❏ AT-123, "DTC P0735 A/T 5TH GEAR FUNCTION"
❏ AT-125, "DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE"
❏ AT-127, "DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)"
❏ AT-129, "DTC P0745 LINE PRESSURE SOLENOID VALVE"
❏ AT-131, "DTC P1705 THROTTLE POSITION SENSOR"
❏ AT-134, "DTC P1710 A/T FLUID TEMPERATURE SENSOR CIRCUIT"
❏ AT-139, "DTC P1721 VEHICLE SPEED SENSOR MTR"
❏ AT-141, "DTC P1730 A/T INTERLOCK"
❏ AT-143, "DTC P1731 A/T 1ST ENGINE BRAKING"
❏ AT-145, "DTC P1752 INPUT CLUTCH SOLENOID VALVE"
❏ AT-147, "DTC P1757 FRONT BRAKE SOLENOID VALVE"
❏ AT-149, "DTC P1762 DIRECT CLUTCH SOLENOID VALVE"
❏ AT-151, "DTC P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE"
❏ AT-153, "DTC P1772 LOW COAST BRAKE SOLENOID VALVE"
❏ AT-155, "DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION"
❏ AT-157, "DTC P1815 MANUAL MODE SWITCH"
5❏ Inspect each system for items found to be NG in the self-diagnostics and repair or replace the malfunctioning parts.
6❏ Perform all road tests and enter the checks again for the required items.AT- 5 2
7❏ For any remaining NG items, perform the “diagnostics procedure” and repair or replace the malfunctioning
parts. See the chart for diagnostics by symptoms. (This chart also contains other symptoms and inspection pro-
cedures.)AT- 5 9
8❏ Erase the results of the self-diagnostics from TCM and ECM.AT- 9 3,
AT- 3 8
AT-52
TROUBLE DIAGNOSIS
Revision: 2006 November2007 350Z
Judgment of Line Pressure Test
ROAD TEST
Description
The road test inspects overall performance of A/T and analyzes possible malfunction causes.
The road test is performed in the following three stages.
1. Check before engine is started. Refer to AT- 5 3 , "
Check Before Engine is Started" .
2. Check at idle. Refer to AT- 5 3 , "
Check at Idle" .
3. Cruise test
–Inspect all the items from Part 1 to Part 3. Refer to AT- 5 5 , "Cruise Test — Part 1" , AT- 5 7 , "Cruise Test —
Part 2" and AT- 5 8 , "Cruise Test — Part 3" .
Before beginning the road test, check the test procedure and inspection items.
Test all inspection items until the symptom is uncovered. Diagnose NG items when all road tests are com-
plete.
Judgment Possible cause
Idle speedLow for all positions
(“P”, “R”, “N”, “D”, “M”)Possible causes include malfunctions in the pressure supply system and low oil pump output.
For example
Oil pump wear
Pressure regulator valve or plug sticking or spring fatigue
Oil strainer oil pump pressure regulator valve passage oil leak
Engine idle speed too low
Only low for a specific
positionPossible causes include an oil pressure leak in a passage or device related to the position after
the pressure is distributed by the manual valve.
HighPossible causes include a sensor malfunction or malfunction in the line pressure adjustment
function.
For example
Accelerator pedal position signal malfunction
A/T fluid temperature sensor malfunction
Line pressure solenoid malfunction (sticking in OFF state, filter clog, cut line)
Pressure regulator valve or plug sticking
Stall speedLine pressure does
not rise higher than
the line pressure for
idle.Possible causes include a sensor malfunction or malfunction in the pressure adjustment func-
tion.
For example
Accelerator pedal position signal malfunction
TCM breakdown
Line pressure solenoid malfunction (shorting, sticking in ON state)
Pressure regulator valve or plug sticking
Pilot valve sticking or pilot filter clogged
The pressure rises,
but does not enter the
standard position.Possible causes include malfunctions in the pressure supply system and malfunction in the
pressure adjustment function.
For example
Accelerator pedal position signal malfunction
Line pressure solenoid malfunction (sticking, filter clog)
Pressure regulator valve or plug sticking
Pilot valve sticking or pilot filter clogged
Only low for a specific
positionPossible causes include an oil pressure leak in a passage or device related to the position after
the pressure is distributed by the manual valve.
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Symptom ChartNCS0002C
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- 4 9 , "A/T Fluid Con-
dition Check".
No. Items Symptom Condition Diagnostic ItemReference
page
1
Shift
ShockLarge shock. (“N” → “
D” position)
Refer to AT-175,
"Large Shock (“N” to
“D” Position)" .ON vehicle1. Engine idle speedEC-76
2. Engine speed signalAT- 11 3
3. Accelerator pedal position sensorAT-131
4. A/T positionAT-206
5. A/T fluid temperature sensorAT-134
6. Front brake solenoid valveAT-147
7. CAN communication lineAT- 9 4
8. A/T fluid level and stateAT- 4 9
9. Line pressure testAT- 5 0
10. Control valve with TCMAT-215
OFF vehicle11. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-17,
"Cross-sectional View" .)AT-255
2Shock is too large
when changing D1 →
D
2 or M1 → M2 .ON vehicle1. Accelerator pedal position sensorAT-131
2. A/T positionAT-206
3. Direct clutch solenoid valveAT-149
4. CAN communication lineAT- 9 4
5. Engine speed signalAT- 11 3
6. Turbine revolution sensorAT-106
7. Vehicle speed sensor A/T and vehicle speed sensor MTRAT-108,
AT-139
8. A/T fluid level and stateAT- 4 9
9. Control valve with TCMAT-215
OFF vehicle 10. Direct clutchAT-288
3Shock is too large
when changing D2 →
D
3 or M2 → M3 .ON vehicle1. Accelerator pedal position sensorAT-131
2. A/T positionAT-206
3. High and low reverse clutch solenoid valveAT-151
4. CAN communication lineAT- 9 4
5. Engine speed signalAT- 11 3
6. Turbine revolution sensorAT-106
7. Vehicle speed sensor A/T and vehicle speed sensor MTRAT-108,
AT-139
8. A/T fluid level and stateAT- 4 9
9. Control valve with TCMAT-215
OFF vehicle 10. High and low reverse clutchAT-286
AT-60
TROUBLE DIAGNOSIS
Revision: 2006 November2007 350Z
4
Shift
ShockShock is too large
when changing D3 →
D
4 or M3 → M4 .ON vehicle1. Accelerator pedal position sensorAT- 1 3 1
2. A/T positionAT- 2 0 6
3. Input clutch solenoid valveAT- 1 4 5
4. CAN communication lineAT- 9 4
5. Engine speed signalAT- 11 3
6. Turbine revolution sensorAT- 1 0 6
7. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 1 0 8,
AT- 1 3 9
8. A/T fluid level and stateAT- 4 9
9. Control valve with TCMAT- 2 1 5
OFF vehicle 10. Input clutchAT- 2 7 6
5Shock is too large
when changing D4 →
D
5 or M4 → M5 .ON vehicle1. Accelerator pedal position sensorAT- 1 3 1
2. A/T positionAT- 2 0 6
3. Front brake solenoid valveAT- 1 4 7
4. CAN communication lineAT- 9 4
5. Engine speed signalAT- 11 3
6. Turbine revolution sensorAT- 1 0 6
7. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 1 0 8,
AT- 1 3 9
8. A/T fluid level and stateAT- 4 9
9. Control valve with TCMAT- 2 1 5
OFF vehicle10. Front brake (brake band)AT- 2 5 511. Input clutchAT- 2 7 6
6Shock is too large for
downshift when accel-
erator pedal is
pressed.ON vehicle1. Accelerator pedal position sensorAT- 1 3 1
2. A/T positionAT- 2 0 6
3. CAN communication lineAT- 9 4
4. Engine speed signalAT- 11 3
5. Turbine revolution sensorAT- 1 0 6
6. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 1 0 8,
AT- 1 3 9
7. A/T fluid level and stateAT- 4 9
8. Control valve with TCMAT- 2 1 5
OFF vehicle9. Front brake (brake band)AT- 2 5 510. Input clutchAT- 2 7 6
11. High and low reverse clutchAT- 2 8 6
12. Direct clutchAT- 2 8 8
No. Items Symptom Condition Diagnostic ItemReference
page