TROUBLE DIAGNOSIS — BASIC INSPECTION
AT-69
[EURO-OBD]
D
E
F
G
H
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MA
B
AT
5. Start engine and measure line pressure at idle and stall speed.
When measuring line pressure at stall speed, follow the
stall test procedure.
LINE PRESSURE
JUDGEMENT OF LINE PRESSURE TEST
SAT493G
Check lock-up hold.Line pressure kPa (bar, kg/cm2 , psi)
“D”, “2” and “1” positions “R” position
Idle 500 (5.00, 5.1, 73) 778 (7.78, 7.9, 113)
Stall 1,233 (12.33, 12.6, 179) 1,918 (19.18, 19.6, 278)
Judgement Suspected parts
At idleLine pressure is low in all positions.
Oil pump wear
Control piston damage
Pressure regulator valve or plug sticking
Spring for pressure regulator valve damaged
Fluid pressure leakage between oil strainer and pressure regulator valve
Clogged strainer
Line pressure is low in particular posi-
tion.
Fluid pressure leakage between manual valve and particular clutch
For example, line pressure is:
− Low in “R” and “1” positions, but
− Normal in “D” and “2” positions.
Therefore, fluid leakage exists at or around low and reverse brake circuit.
Refer to AT- 2 3
.
Line pressure is high.
Maladjustment of throttle position sensor
A/T fluid temperature sensor damaged
Line pressure solenoid valve sticking
Short circuit of line pressure solenoid valve circuit
Pressure modifier valve sticking
Pressure regulator valve or plug sticking
Open in dropping resistor circuit
At stall
speedLine pressure is low.
Maladjustment of throttle position sensor
Line pressure solenoid valve sticking
Short circuit of line pressure solenoid valve circuit
Pressure regulator valve or plug sticking
Pressure modifier valve sticking
Pilot valve sticking
TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
AT-85
[EURO-OBD]
D
E
F
G
H
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K
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MA
B
AT
TROUBLE DIAGNOSIS — GENERAL DESCRIPTIONPFP:00000
Symptom ChartECS004QU
Numbers are arranged in order of inspection.
Perform inspections starting with number one and work up.
Symptom Condition Diagnostic Item Reference Page
Engine cannot start in “P” and “N”
positions.
AT- 2 0 6
ON vehicle1. Ignition switch and starterPG-2
, SC-23
2. Control cable adjustmentAT-409
3. PNP switchAT-100
Engine starts in position other than
“N” and “P” positions.
AT- 2 0 6
ON vehicle1. Control cable adjustmentAT-4092. PNP switchAT-100
Transaxle noise in “P” and “N” posi-
tions.ON vehicle1. Fluid levelAT- 6 4
2. Line pressure testAT- 6 8
3. Accelerator pedal position (APP) sensorAT-173
4. Vehicle speed sensor·A/T (Revolution
sensor) and vehicle speed sensor·MTRAT- 11 2,
AT-192
OFF vehicle5. Oil pumpAT-4436. Torque converterAT-423
Vehicle moves when changing into
“P” position, or parking gear does
not disengage when shifted out of
“P” position.
AT- 2 0 7ON vehicle 1. Control cable adjustmentAT-409
OFF vehicle 2. Parking componentsAT- 4 1 6, AT-440
Vehicle runs in “N” position.
AT- 2 0 8
ON vehicle 1. Control cable adjustmentAT-409
OFF vehicle2. Forward clutchAT-4753. Reverse clutchAT-464
4. Overrun clutchAT-475
Vehicle will not run in “R” position
(but runs in “D”, “2” and “1” posi-
tions). Clutch slips.
Very poor acceleration.
AT- 2 1 0
ON vehicle1. Control cable adjustmentAT-409
2. Stall testAT- 6 5
3. Line pressure testAT- 6 8
4. Line pressure solenoid valveAT-154
5. Control valve assemblyAT-404
Vehicle will not run in “R” position
(but runs in “D”, “2” and “1” posi-
tions). Clutch slips.
Very poor acceleration.
AT- 2 1 0
OFF vehicle6. Reverse clutchAT-464
7. High clutchAT-469
8. Forward clutchAT-475
9. Overrun clutchAT-475
10. Low & reverse brakeAT-483
Vehicle braked when shifting into
“R” position.ON vehicle1. Fluid levelAT- 6 4
2. Line pressure testAT- 6 8
3. Line pressure solenoid valveAT-154
4. Control valve assemblyAT-404
OFF vehicle5. High clutchAT-4696. Brake bandAT-497
7. Forward clutchAT-475
8. Overrun clutchAT-475
AT-86
[EURO-OBD]
TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
Sharp shock in shifting from “N” to
“D” position.ON vehicle1. Engine idling rpmEC-45
2. Accelerator pedal position (APP) sensorAT-173
3. Line pressure testAT- 6 8
4. A/T fluid temperature sensorAT-184
5. Engine speed signalAT- 11 9
6. Line pressure solenoid valveAT-154
7. Control valve assemblyAT-404
8. Accumulator N-DAT-404
OFF vehicle 9. Forward clutchAT-475
Vehicle will not run in “D” and “2”
positions (but runs in “1” and “R”
positions).ON vehicle 1. Control cable adjustmentAT-409
OFF vehicle 2. Low one-way clutchAT-416, AT- 4 2 3
Vehicle will not run in “D”, “1”, “2”
positions (but runs in “R” position).
Clutch slips. Very poor acceleration.
AT- 2 1 2
ON vehicle1. Fluid levelAT- 6 4
2. Stall testAT- 6 5
3. Line pressure testAT- 6 8
4. Line pressure solenoid valveAT-154
5. Control valve assemblyAT-404
6. Accumulator N-DAT-404
Vehicle will not run in “D”, “1”, “2”
positions (but runs in “R” position).
Clutch slips. Very poor acceleration.
AT- 2 1 2
OFF vehicle7. Reverse clutchAT-464
8. High clutchAT-469
9. Forward clutchAT-475
10. Forward one-way clutchAT-416
11. Low one-way clutchAT-416, AT- 4 2 3
Clutches or brakes slip somewhat in
starting.ON vehicle1. Fluid levelAT- 6 4
2. Control cable adjustmentAT-409
3. Accelerator pedal position (APP) sensorAT-173
4. Line pressure testAT- 6 8
5. Line pressure solenoid valveAT-154
6. Control valve assemblyAT-404
7. Accumulator N-DAT-404
8. Shift solenoid valve AAT-161
9. Shift solenoid valve BAT-167
10. Overrun clutch solenoid valveAT-178
11. Torque converter clutch solenoid valveAT-148
OFF vehicle12. Forward clutchAT-475
13. Reverse clutchAT-464
14. Low & reverse brakeAT-483
15. Oil pumpAT-443
16. Torque converterAT-423
Excessive creep. ON vehicle 1. Engine idling rpm EC-45
Symptom Condition Diagnostic Item Reference Page
TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
AT-87
[EURO-OBD]
D
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B
AT
No creep at all.
AT- 2 1 0
and AT-212
ON vehicle1. Fluid levelAT- 6 42. Line pressure testAT-387
3. Control valve assemblyAT-404
OFF vehicle4. Forward clutchAT-4755. Oil pumpAT-443
6. Torque converterAT-423
Failure to change gear from “D1 ” to
“D
2 ”.ON vehicle1. Control cable adjustmentAT-409
2. Shift solenoid valve AAT-161
3. Control valve assemblyAT-404
4. Vehicle speed sensor·A/T (Revolution
sensor) and vehicle speed sensor·MTRAT- 11 2, AT- 1 9 2
5. Accelerator pedal position (APP) sensorAT-173
OFF vehicle 6. Brake bandAT-497
Failure to change gear from “D2 ” to
“D
3 ”.ON vehicle1. Control cable adjustmentAT-409
2. Shift solenoid valve BAT-167
3. Control valve assemblyAT-404
4. Vehicle speed sensor·A/T (Revolution
sensor) and vehicle speed sensor·MTRAT- 11 2, AT- 1 9 2
5. Accelerator pedal position (APP) sensorAT-173
OFF vehicle6. High clutchAT-4697. Brake bandAT-497
Failure to change gear from “D3 ” to
“D
4 ”.ON vehicle1. PNP switchAT-100
2. Overdrive control switchAT-237
3. Shift solenoid valve AAT-161
4. Vehicle speed sensor·A/T (Revolution
sensor) and vehicle speed sensor·MTRAT- 11 2, AT- 1 9 2
5. A/T fluid temperature sensorAT-184
OFF vehicle 6. Brake bandAT-497
Too high a gear change point from
“D
1 ” to “D2 ”, from “D2 ” to “D3 ”,
from “D
3 ” to “D4 ”.
AT- 2 1 7
, AT- 2 2 0 and AT-222
ON vehicle1. Accelerator pedal position (APP) sensorAT-173
2. Vehicle speed sensor·A/T (Revolution
sensor) and vehicle speed sensor·MTRAT- 11 2, AT- 1 9 2
3. Shift solenoid valve AAT-161
4. Shift solenoid valve BAT-167
Gear change directly from “D1 ” to
“D
3 ” occurs.ON vehicle1. Fluid levelAT- 6 42. Accumulator servo releaseAT-404
OFF vehicle 3. Brake bandAT-497
Engine stops when shifting lever
into “R”, “D”, “2” and “1”.ON vehicle1. Engine idling rpm EC-45
2. Fluid levelAT- 6 4
3. Torque converter clutch solenoid valveAT-148
4. Control valve assemblyAT-404
OFF vehicle 5. Torque converterAT-423
Symptom Condition Diagnostic Item Reference Page
TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
AT-89
[EURO-OBD]
D
E
F
G
H
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MA
B
AT
Vehicle braked by gear change from
“D
3 ” to “D4 ”.ON vehicle 1. Fluid levelAT- 6 4OFF vehicle2. Overrun clutchAT-3623. Forward one-way clutchAT-416
4. Reverse clutchAT-464
Maximum speed not attained.
Acceleration poor.ON vehicle1. Fluid levelAT- 6 4
2. PNP switchAT-100
3. Overdrive control switchAT-237
4. Accelerator pedal position (APP) sensorAT-173
5. Shift solenoid valve AAT-161
6. Shift solenoid valve BAT-167
7. Control valve assemblyAT-404
OFF vehicle8. Reverse clutchAT-464
9. High clutchAT-469
10. Brake bandAT-497
11. Low & reverse brakeAT-483
12. Oil pumpAT-443
13. Torque converterAT-423
Failure to change gear from “D4 ” to
“D
3 ”.ON vehicle1. Fluid levelAT- 6 4
2. Accelerator pedal position (APP) sensorAT-173
3. Overrun clutch solenoid valveAT-178
4. Shift solenoid valve AAT-161
5. Line pressure solenoid valveAT-154
6. Control valve assemblyAT-404
OFF vehicle7. Brake bandAT-4978. Overrun clutchAT-475
Failure to change gear from “D3 ” to
“D
2 ” or from “D4 ” to “D2 ”.ON vehicle1. Fluid levelAT- 6 4
2. Accelerator pedal position (APP) sensorAT-173
3. Shift solenoid valve AAT-161
4. Shift solenoid valve BAT-167
5. Control valve assemblyAT-404
OFF vehicle6. High clutchAT-4697. Brake bandAT-497
Failure to change gear from “D2 ” to
“D
1 ” or from “D3 ” to “D1 ”.ON vehicle1. Fluid levelAT- 6 4
2. Accelerator pedal position (APP) sensorAT-173
3. Shift solenoid valve AAT-161
4. Shift solenoid valve BAT-167
5. Control valve assemblyAT-404
OFF vehicle6. Low one-way clutchAT- 4 1 6
, AT-423
7. High clutchAT-469
8. Brake bandAT-497
Gear change shock felt during
deceleration by releasing accelera-
tor pedal.ON vehicle1. Accelerator pedal position (APP) sensorAT-1732. Line pressure testAT- 6 8
3. Overrun clutch solenoid valveAT-178
4. Control valve assemblyAT-404
Symptom Condition Diagnostic Item Reference Page
TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
AT-91
[EURO-OBD]
D
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MA
B
AT
Races extremely fast or slips in
changing from “D
4 ” or “D3 ” to “D1 ”
when depressing pedal.ON vehicle1. Fluid levelAT- 6 4
2. Accelerator pedal position (APP) sensorAT-173
3. Line pressure testAT- 6 8
4. Line pressure solenoid valveAT-154
5. Shift solenoid valve AAT-161
6. Shift solenoid valve BAT-167
7. Control valve assemblyAT-404
OFF vehicle8. Forward clutchAT-4759. Forward one-way clutchAT-416
10. Low one-way clutchAT- 4 1 6, AT-423
Vehicle will not run in any position.ON vehicle1. Fluid levelAT- 6 4
2. Control cable adjustmentAT-409
3. Line pressure testAT- 6 8
4. Line pressure solenoid valveAT-154
OFF vehicle5. Oil pumpAT-4436. Torque converterAT-423
7. Parking componentsAT-416
Transaxle noise in “D”, “2”, “1” and
“R” positions.ON vehicle 1. Fluid levelAT- 6 4
OFF vehicle 2. Torque converterAT-423
Failure to change from “D3 ” to “22 ”
when changing lever into “2” posi-
tion.
AT- 2 3 2
ON vehicle1. Accelerator pedal position (APP) sensorAT-1732. Shift solenoid valve BAT-167
3. Control valve assemblyAT-404
4. Control cable adjustmentAT-409
Failure to change from “D3 ” to “22 ”
when changing lever into “2” posi-
tion.
AT- 2 3 2
OFF vehicle 5. Brake bandAT-497
Gear change from “22 ” to “23 ” in “2”
position.ON vehicle1. PNP switchAT-100
2. Control cable adjustmentAT-409
Engine brake does not operate in
“1” position.
AT- 2 3 0ON vehicle1. PNP switchAT-100
2. Control cable adjustmentAT-409
3. Vehicle speed sensor·A/T (Revolution
sensor) and vehicle speed sensor·MTRAT- 11 2, AT- 1 9 2
4. Control valve assemblyAT-404
5. Overrun clutch solenoid valveAT-178
OFF vehicle6. Overrun clutchAT-4757. Low & reverse brakeAT-483
Gear change from “11 ” to “12 ” in “1”
position.ON vehicle1. PNP switchAT-100
2. Control cable adjustmentAT-409
Symptom Condition Diagnostic Item Reference Page
AT-92
[EURO-OBD]
TROUBLE DIAGNOSIS — GENERAL DESCRIPTION
Does not change from “12 ” to “11 ”
in “1” position.ON vehicle1. PNP switchAT-100
2. Vehicle speed sensor·A/T (Revolution
sensor) and vehicle speed sensor·MTRAT- 11 2, AT- 1 9 2
3. Shift solenoid valve AAT-161
4. Control valve assemblyAT-404
OFF vehicle5. Low one-way clutchAT-416
, AT- 4 2 3
6. Brake bandAT-497
7. Low & reverse brakeAT-483
Large shock changing from “12 ” to
“1
1 ” in “1” position.ON vehicle 1. Control valve assemblyAT-404OFF vehicle 2. Low & reverse brakeAT-483
Transaxle overheats. ON vehicle1. Fluid levelAT- 6 4
2. Engine idling rpm EC-45
3. Accelerator pedal position (APP) sensorAT-173
4. Line pressure testAT- 6 8
5. Line pressure solenoid valveAT-154
6. Control valve assemblyAT-404
Transaxle overheats. OFF vehicle7. Oil pumpAT-443
8. Reverse clutchAT-464
9. High clutchAT-469
10. Brake bandAT-497
11. Forward clutchAT-475
12. Overrun clutchAT-475
13. Low & reverse brakeAT-483
14. Torque converterAT-423
ATF shoots out during operation.
White smoke emitted from exhaust
pipe during operation.ON vehicle 1. Fluid levelAT- 6 4
OFF vehicle2. Reverse clutchAT-464
3. High clutchAT-469
4. Brake bandAT-497
5. Forward clutchAT-475
6. Overrun clutchAT-475
7. Low & reverse brakeAT-483
Offensive smell at fluid charging
pipe.ON vehicle 1. Fluid levelAT- 6 4
OFF vehicle2. Torque converterAT-423
3. Oil pumpAT-443
4. Reverse clutchAT-464
5. High clutchAT-469
6. Brake bandAT-497
7. Forward clutchAT-475
8. Overrun clutchAT-475
9. Low & reverse brakeAT-483
Symptom Condition Diagnostic Item Reference Page
AT-140
[EURO-OBD]
DTC P0734 A/T 4TH GEAR FUNCTION
DTC P0734 A/T 4TH GEAR FUNCTIONPFP:31940
DescriptionECS004RM
This malfunction will not be detected while the O/D OFF indicator lamp is indicating another self-diagnosis
malfunction.
This malfunction is detected when the A/T does not shift into fourth gear position or line pressure is low as
instructed by the TCM. This is not caused by electrical malfunction (circuits open or shorted) but by
mechanical malfunction such as control valve sticking, improper solenoid valve operation, malfunctioning
oil pump or torque converter clutch, etc.
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Specification data are reference values.
On Board Diagnosis LogicECS00CU1
This diagnosis monitors actual gear position by checking the torque converter slip ratio calculated by TCM as
follows:
Torque converter slip ratio = A x C/B
A: Output shaft revolution signal from revolution sensor
B: Engine speed signal from ECM
C: Gear ratio determined as gear position which TCM supposes
If the actual gear position is much lower than the position (4th) supposed by TCM, the slip ratio will be much
less than normal. In case the ratio does not reach the specified value, TCM judges this diagnosis malfunction.
This malfunction will be caused when shift solenoid valve A is stuck open or shift solenoid valve B is stuck
closed.
*: P0734 is detected.
And also, this malfunction will be caused when line pressure is lower than normal same as line pressure sole-
noid valve stuck open.
Gear position 1 2 3 4
Shift solenoid valve A ON (Closed) OFF (Open) OFF (Open) ON (Closed)
Shift solenoid valve B ON (Closed) ON (Closed) OFF (Open) OFF (Open)
Monitor item Condition Specification
Line pressure solenoid valve dutySmall throttle opening
(Low line pressure)
↓
Large throttle opening
(High line pressure)Approximately 24%
↓
Approximately 95%
Gear position supposed by TCM 1 2 3 4
In case of gear position with no malfunctions 1 2 34
In case of gear position with shift solenoid valve A stuck open 2 2 33*
In case of gear position with shift solenoid valve B stuck closed 1 2 21*
Diagnostic trouble code Malfunction is detected when... Check items (Possible cause)
: A/T 4TH GR FNCTN
A/T cannot be shifted to the 4th gear posi-
tion even if electrical circuit is good.
Shift solenoid valve A
Shift solenoid valve B
Line pressure solenoid valve
Each clutch
Hydraulic control circuit : P0734