
AT-42
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
TROUBLE DIAGNOSISPFP:00004
DTC Inspection Priority ChartACS007A2
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 DTC, first perform the trouble diagnosis for “DTC U1000 CAN
COMMUNICATION LINE”. Refer to AT- 1 0 5
.
Fail-SafeACS007A3
The TCM has an electrical fail-safe mode. This mode makes it possible to operate even if there is a an mal-
function in a main electronic control input/output signal circuit.
In fail-safe mode, even if the selector lever is “D” or “M” mode, the transmission is fixed in 2nd or 4th (depend-
ing on the breakdown position), so the customer should feel “slipping” or “poor acceleration”. When fail-safe
mode is triggered, when the ignition switch is switched “ON”, the A/T CHECK indicator lamp flashes for about
8 seconds. (Refer to AT- 1 0 3 , "
TCM SELF-DIAGNOSTIC PROCEDURE (NO TOOLS)" ).
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. Also, the A/T CHECK indicator lamp flashes for about 8 seconds once, then is
cleared. Therefore, the customer's vehicle has returned to normal, so handle according to the “diagnostics
flow” (Refer to AT- 4 5
).
FAIL-SAFE FUNCTION
If any malfunction occurs in a sensor or solenoid, this function controls the A/T to make driving possible.
Vehicle Speed Sensor A/T (Revolution 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 and
manual mode are prohibited.
Accelerator Pedal Position Sensor
If there is a malfunction in one of the systems, the accelerator opening angle is controlled by ECM accord-
ing 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 accord-
ing 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 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.)
Priority Detected items (DTC)
1 U1000 CAN communication line
2 Except above

AT-48
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
44-3Part 2
AT- 6 0
❏ AT-203, "Vehicle Cannot Be Started From D1" .
❏ AT-206, "
A/T Does Not Shift: D1 → D2" .
❏ AT-208, "
A/T Does Not Shift: D2 → D3" .
❏ AT- 2 11 , "
A/T Does Not Shift: D3 → D4" .
Part 3
AT- 6 1
❏ AT-222, "Cannot Be Changed to Manual Mode" .
❏ AT-223, "
A/T Does Not Shift: 5th gear → 4th gear" .
❏ AT-225, "
A/T Does Not Shift: 4th gear → 3rd gear" .
❏ AT-227, "
A/T Does Not Shift: 3rd gear → 2nd gear" .
❏ AT-229, "
A/T Does Not Shift: 2nd gear → 1st gear" .
❏ AT-231, "
Vehicle Does Not Decelerate By Engine Brake" .
❏ Perform self-diagnostics. Enter checks for detected items. AT- 9 4
, AT-103
❏ AT-105, "DTC U1000 CAN COMMUNICATION LINE" .
❏ AT-108, "
DTC P0615 START SIGNAL CIRCUIT" .
❏ AT- 11 2 , "
DTC P0705 PARK/NEUTRAL POSITION SWITCH" .
❏ AT- 11 6 , "
DTC P0720 VEHICLE SPEED SENSOR A/T (REVOLUTION SENSOR)" .
❏ AT-121, "
DTC P0725 ENGINE SPEED SIGNAL" .
❏ AT-121, "
DTC P0725 ENGINE SPEED SIGNAL" .
❏ AT-123, "
DTC P0740 TORQUE CONVERTER CLUTCH SOLENOID VALVE" .
❏ AT-125, "
DTC P0744 A/T TCC S/V FUNCTION (LOCK-UP)" .
❏ AT-127, "
DTC P0745 LINE PRESSURE SOLENOID VALVE" .
❏ AT-129, "
DTC P1701 TRANSMISSION CONTROL MODULE (POWER SUPPLY)" .
❏ AT-133, "
DTC P1702 TRANSMISSION CONTROL MODULE (RAM)" .
❏ AT-134, "
DTC P1703 TRANSMISSION CONTROL MODULE (ROM)" .
❏ AT-135, "
DTC P1704 TRANSMISSION CONTROL MODULE (EEPROM)" .
❏ AT-136, "
DTC P1705 THROTTLE POSITION SENSOR" .
❏ AT-139, "
DTC P1710 A/T FLUID TEMPERATURE SENSOR CIRCUIT" .
❏ AT-143, "
DTC P1716 TURBINE REVOLUTION SENSOR" .
❏ AT-145, "
DTC P1721 VEHICLE SPEED SENSOR MTR" .
❏ AT-147, "
DTC P1730 A/T INTERLOCK" .
❏ AT-150, "
DTC P1731 A/T 1ST ENGINE BRAKING" .
❏ AT-152, "
DTC P1752 INPUT CLUTCH SOLENOID VALVE" .
❏ AT-154, "
DTC P1754 INPUT CLUTCH SOLENOID VALVE FUNCTION" .
❏ AT-156, "
DTC P1757 FRONT BRAKE SOLENOID VALVE" .
❏ AT-158, "
DTC P1759 FRONT BRAKE SOLENOID VALVE FUNCTION" .
❏ AT-160, "
DTC P1762 DIRECT CLUTCH SOLENOID VALVE" .
❏ AT-162, "
DTC P1764 DIRECT CLUTCH SOLENOID VALVE FUNCTION" .
❏ AT-164, "
DTC P1767 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE" .
❏ AT-166, "
DTC P1769 HIGH AND LOW REVERSE CLUTCH SOLENOID VALVE
FUNCTION" .
❏ AT-168, "
DTC P1772 LOW COAST BRAKE SOLENOID VALVE" .
❏ AT-170, "
DTC P1774 LOW COAST BRAKE SOLENOID VALVE FUNCTION" .
❏ AT-172, "
DTC P1815 MANUAL MODE SWITCH" .
❏ AT-178, "
DTC P1841 ATF PRESSURE SWITCH 1" .
❏ AT-180, "
DTC P1843 ATF PRESSURE SWITCH 3" .
❏ AT-182, "
DTC P1845 ATF PRESSURE SWITCH 5" .
❏ AT-184, "
DTC P1846 ATF PRESSURE SWITCH 6" .
5❏ Inspect each system for items found to be NG in the self-diagnostics and repair or replace the malfunction
parts.
6❏ Perform all road tests and enter the checks again for the required items.AT- 5 4
7❏ For any remaining NG items, perform the “diagnostics procedure” and repair or replace the malfunction parts.
See the chart for diagnostics by symptoms. (This chart also contains other symptoms and inspection proce-
dures.)AT- 6 5
8❏ Erase the results of the self-diagnostics from the TCM.AT- 4 0,
AT- 1 0 4

AT-70
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
16
No Down
ShiftIn D or M range, does
not downshift to 2nd
gear.
Refer to AT-227, "A/T
Does Not Shift: 3rd
gear → 2nd gear" .ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 6,
AT- 1 4 5
3. ATF pressure switch 6, high and low reverse clutch sole-
noid valveAT- 1 8 4
,
AT- 1 6 4
4. CAN communication lineAT- 1 0 5
5. Line pressure testAT- 5 2
6. Control valve with TCMAT- 2 4 2
OFF vehicle 7. High and low reverse clutchAT- 3 2 0
17In D or M range, does
not downshift to 1st
gear.
Refer to AT-229, "A/T
Does Not Shift: 2nd
gear → 1st gear" .ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 6,
AT- 1 4 5
3. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 8 2,
AT- 1 6 0
4. CAN communication lineAT- 1 0 5
5. Line pressure testAT- 5 2
6. Control valve with TCMAT- 2 4 2
OFF vehicle 7. Direct clutchAT- 3 2 3
18Slips/Will
Not
engageWhen D or M position,
remains in 1st gear.ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 6,
AT- 1 4 5
3. Direct clutch solenoid valveAT- 1 6 0
4. Line pressure testAT- 5 2
5. CAN communication lineAT- 1 0 5
6. Control valve with TCMAT- 2 4 2
OFF vehicle7. 3rd one-way clutchAT- 3 0 6
8. 1st one-way clutchAT- 3 1 4
9. Gear systemAT- 2 7 4
10. Reverse brakeAT- 2 8 6
11. Forward one-way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT-17, "
Cross-Sectional View (2WD Models)" or AT-18,
"Cross-Sectional View (AWD Models)" )AT- 2 8 6
12. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-17,
"Cross-Sectional View (2WD Models)" or AT- 1 8 , "Cross-
Sectional View (AWD Models)" )AT- 2 8 6
No. Items Symptom Condition Diagnostic ItemReference
page

TROUBLE DIAGNOSIS
AT-71
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: 2004 November 2004 FX35/FX45
19
Slips/Will
Not
engageWhen D or M position,
remains in 2nd gear.ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 6,
AT-145
3. Low coast brake solenoid valveAT-168
4. Line pressure testAT- 5 2
5. CAN communication lineAT-105
6. Control valve with TCMAT-242
OFF vehicle7. 3rd one-way clutchAT-306
8. Gear systemAT-274
9. Direct clutchAT-323
10. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-17,
"Cross-Sectional View (2WD Models)" or AT-18, "Cross-
Sectional View (AWD Models)" )AT-286
20When D or M position,
remains in 3rd gear.ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 6,
AT-145
3. Line pressure testAT- 5 2
4. CAN communication lineAT-105
5. Control valve with TCMAT-242
OFF vehicle6. 3rd one-way clutchAT-306
7. Gear systemAT-274
8. High and low reverse clutchAT-320
9. Forward one-way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT- 1 7 , "
Cross-Sectional View (2WD Models)" or AT- 1 8 ,
"Cross-Sectional View (AWD Models)" )AT-286
10. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-17,
"Cross-Sectional View (2WD Models)" or AT-18, "Cross-
Sectional View (AWD Models)" )AT-286
No. Items Symptom Condition Diagnostic ItemReference
page

AT-72
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
21
Slips/Will
Not
engageWhen D or M position,
remains in 4th gear.ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 6,
AT- 1 4 5
3. ATF pressure switch 3 and input clutch solenoid valveAT- 1 8 0,
AT- 1 5 2
4. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 8 2,
AT- 1 6 0
5. ATF pressure switch 6, high and low reverse clutch sole-
noid valveAT- 1 8 4,
AT- 1 6 4
6. Low coast brake solenoid valveAT- 1 6 8
7. Front brake solenoid valveAT- 1 5 6
8. Line pressure testAT- 5 2
9. CAN communication lineAT- 1 0 5
10. Control valve with TCMAT- 2 4 2
OFF vehicle11. Input clutchAT- 3 0 812. Gear systemAT- 2 7 4
13. High and low reverse clutchAT- 3 2 0
14. Direct clutchAT- 3 2 3
22When D or M position,
remains in 5th gear.ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 6,
AT- 1 4 5
3. ATF pressure switch 1 and front brake solenoid valveAT- 1 7 8
,
AT- 1 5 6
4. Line pressure testAT- 5 2
5. CAN communication lineAT- 1 0 5
6. Control valve with TCMAT- 2 4 2
OFF vehicle7. Front brake (brake band)AT- 2 8 68. Input clutchAT- 3 0 8
9. Gear systemAT- 2 7 4
10. High and low reverse clutchAT- 3 2 0
No. Items Symptom Condition Diagnostic ItemReference
page

TROUBLE DIAGNOSIS
AT-73
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: 2004 November 2004 FX35/FX45
23
Slips/Will
Not
EngageVehicle cannot be
started from D
1 .
Refer to AT-203,
"Vehicle Cannot Be
Started From D1" .ON vehicle1. Fluid level and stateAT- 5 1
2. Accelerator pedal position sensorAT-136
3. Line pressure testAT- 5 2
4. CAN communication lineAT-105
5. Control valve with TCMAT-242
OFF vehicle6. Torque converterAT-286
7. Oil pump assemblyAT-303
8. 3rd one-way clutchAT-306
9. 1st one-way clutch AT-314
10. Gear systemAT-274
11. Reverse brakeAT-286
12. Forward one-way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT- 1 7 , "
Cross-Sectional View (2WD Models)" or AT- 1 8 ,
"Cross-Sectional View (AWD Models)" )AT-286
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-17,
"Cross-Sectional View (2WD Models)" or AT-18, "Cross-
Sectional View (AWD Models)" )AT-286
24Does not lock-up.
Refer to AT-216, "A/T
Does Not Perform
Lock-up" .ON vehicle1. Fluid level and stateAT- 5 1
2. Line pressure testAT- 5 2
3. Engine speed signalAT-121
4. Turbine revolution sensorAT-143
5. Torque converter clutch solenoid valveAT-123
6. CAN communication lineAT-105
7. Control valve with TCMAT-242
OFF vehicle8. Torque converterAT-2869. Oil pump assemblyAT-303
25Does not hold lock-up
condition.
Refer to AT-218, "A/T
Does Not Hold Lock-
up Condition" .ON vehicle1. Fluid level and stateAT- 5 1
2. Line pressure testAT- 5 2
3. Engine speed signalAT-121
4. Turbine revolution sensorAT-143
5. Torque converter clutch solenoid valveAT-123
6. CAN communication lineAT-105
7. Control valve with TCMAT-242
OFF vehicle8. Torque converterAT-2869. Oil pump assemblyAT-303
No. Items Symptom Condition Diagnostic ItemReference
page

AT-74
TROUBLE DIAGNOSIS
Revision: 2004 November 2004 FX35/FX45
26
Slips/Will
Not
engageLock-up is not
released.
Refer to AT-220,
"Lock-up Is Not
Released" .ON vehicle1. Fluid level and stateAT- 5 1
2. Line pressure testAT- 5 2
3. Engine speed signalAT- 1 2 1
4. Turbine revolution sensorAT- 1 4 3
5. Torque converter clutch solenoid valveAT- 1 2 3
6. CAN communication lineAT- 1 0 5
7. Control valve with TCMAT- 2 4 2
OFF vehicle8. Torque converterAT- 2 8 69. Oil pump assemblyAT- 3 0 3
27No shock at all or the
clutch slips when
vehicle changes
speed D
1 → D2 or
M
1 → M2 . ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 6,
AT- 1 4 5
3. ATF pressure switch 5 and direct clutch solenoid valveAT- 1 8 2,
AT- 1 6 0
4. CAN communication lineAT- 1 0 5
5. Line pressure testAT- 5 2
6. Control valve with TCMAT- 2 4 2
OFF vehicle7. Torque converterAT- 2 8 6
8. Oil pump assemblyAT- 3 0 3
9. 3rd one-way clutchAT- 3 0 6
10. Gear systemAT- 2 7 4
11. Direct clutchAT- 3 2 3
12. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-17,
"Cross-Sectional View (2WD Models)" or AT- 1 8 , "Cross-
Sectional View (AWD Models)" )AT- 2 8 6
No. Items Symptom Condition Diagnostic ItemReference
page

TROUBLE DIAGNOSIS
AT-75
D
E
F
G
H
I
J
K
L
MA
B
AT
Revision: 2004 November 2004 FX35/FX45
28
Slips/Will
Not
engageNo shock at all or the
clutch slips when
vehicle changes
speed D
2 → D3 or
M
2 → M3 .ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 6,
AT-145
3. ATF pressure switch 6, high and low reverse clutch sole-
noid valveAT-184,
AT-164
4. CAN communication lineAT-105
5. Line pressure testAT- 5 2
6. Control valve with TCMAT-242
OFF vehicle7. Torque converterAT-286
8. Oil pump assemblyAT-303
9. 3rd one-way clutchAT-306
10. Gear systemAT-274
11. High and low reverse clutchAT-320
12. Forward one-way clutch (Parts behind drum support is
impossible to perform inspection by disassembly. Refer to
AT- 1 7 , "
Cross-Sectional View (2WD Models)" or AT- 1 8 ,
"Cross-Sectional View (AWD Models)" )AT-286
13. Forward brake (Parts behind drum support is impossible
to perform inspection by disassembly. Refer to AT-17,
"Cross-Sectional View (2WD Models)" or AT-18, "Cross-
Sectional View (AWD Models)" )AT-286
29No shock at all or the
clutch slips when
vehicle changes
speed D
3 → D4 or
M
3 → M4 .ON vehicle1. Fluid level and stateAT- 5 1
2. Vehicle speed sensor A/T and vehicle speed sensor MTRAT- 11 6,
AT-145
3. ATF pressure switch 3 and input clutch solenoid valveAT-180,
AT-152
4. ATF pressure switch 1 and front brake solenoid valveAT-178
,
AT-156
5. CAN communication lineAT-105
6. Line pressure testAT- 5 2
7. Control valve with TCMAT-242
OFF vehicle8. Torque converterAT-286
9. Oil pump assemblyAT-303
10. Input clutchAT-308
11. Gear systemAT-274
12. High and low reverse clutchAT-320
13. Direct clutchAT-323
No. Items Symptom Condition Diagnostic ItemReference
page