
DIAGNOSTIC PROCEDURE
CHECK PARK/NEUTRAL POSITION
SWITCH CIRCUIT.
1. Turn ignition switch to ªONº posi-tion.
(Do not start engine.)
2. Select ªECU INPUT SIGNALSº in Data Monitor.
3. Read out ªR, N, D, 2 and 1 posi- tion switchesº moving selector
lever to each position.
Check the signal of the selector
lever position is indicated properly.
---------------------------------------------------------------------------------------------------------------------- -OR -----------------------------------------------------------------------------------------------------------------------
1. Turn ignition switch to ªONº posi-
tion. (Do not start engine.)
2. Check voltage between TCM ter- minals q
26,q27,q34,q35,q36and
ground while moving selector
lever through each position.
Voltage: B: Battery voltage
0: 0V
OK
ENG Check the following items:
IPark/neutral position
switch
Refer to ªCOMPONENT
INSPECTIONº, AT-119.
I Harness for short or
open between ignition
switch and park/neutral
position switch (Main
harness)
I Harness for short or
open between park/
neutral position switch
and TCM (Main harness)
I Diode
qA
(Go to next page.)
Lever position Terminal No.
q36q35q34q27q26
P, N B0000
R0 B000
D00 B00
2 000 B0
1 0000 B
YAT326
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TROUBLE DIAGNOSIS FOR NON-DETECTABLE ITEMS
Park/neutral Position, Overdrive Control or
Throttle (Accelerator) Position Switches
(Cont'd)
AT-94
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qA
CHECK OVERDRIVE CONTROL
SWITCH CIRCUIT.
1. Turn ignition switch to ªONº posi-tion.
(Do not start engine.)
2. Select ªECU INPUT SIGNALSº in Data Monitor.
3. Read out ªOVERDRIVE SWITCHº. Check the signal of the overdrive
control switch is indicated prop-
erly.
(Overdrive control switch ªONº
displayed on CONSULT-II means
overdrive ªOFFº.)
---------------------------------------------------------------------------------------------------------------------- -OR -----------------------------------------------------------------------------------------------------------------------
1. Turn ignition switch to ªONº posi-
tion.
(Do not start engine.)
2. Check voltage between TCM ter- minal q
22and ground when over-
drive control switch is ªONº and
ªOFFº.
OK
ENG Check the following items.
IOverdrive control switch
Refer to ªCOMPONENT
INSPECTIONº, AT-119.
I Harness for short or
open between TCM and
overdrive control switch
(Main harness)
I Harness for short or
open of ground circuit for
overdrive control switch
(Main harness)
qB(Go to next page.)
Switch position Voltage
ON Battery voltage
OFF 1V or less
YAT327
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TROUBLE DIAGNOSIS FOR NON-DETECTABLE ITEMS
Park/neutral Position, Overdrive Control or
Throttle (Accelerator) Position Switches
(Cont'd)
AT-95
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qB
CHECK THROTTLE (ACCELERATOR)
POSITION SWITCH CIRCUIT.
1. Turn ignition switch to ªONº posi-tion.
(Do not start engine.)
2. Select ªECU INPUT SIGNALSº in Data Monitor.
3. Read out ªCLOSED THL/SWº and ªW/O THRL/P-SWº depressing
and releasing accelerator pedal.
Check the signal of throttle (accel-
erator) position switch is indicated
properly.
---------------------------------------------------------------------------------------------------------------------- -OR -----------------------------------------------------------------------------------------------------------------------
1. Turn ignition switch to ªONº posi-
tion.
(Do not start engine.)
2. Check voltage between TCM ter- minals q
16,q17and ground while
depressing, and releasing accel-
erator pedal slowly. (after warming
up engine)
OK
ENG Check the following items:
IThrottle (accelerator)
position switch
Refer to ªCOMPONENT
INSPECTIONº, AT-119.
I Harness for short or
open between ignition
switch and throttle
(accelerator) position
switch (Main harness)
I Harness for short or
open between throttle
(accelerator) position
switch and TCM (Main
harness)
Perform ªDIAGNOSTIC PROCEDUREº,
AT-94.
OK
ENG
1. Perform TCM input/
output signal inspection.
2. If NG, recheck TCM pin terminals for damage or
loose connection with
harness connector.
INSPECTION END
Accelerator
pedal condi- tion Data monitor
CLOSED THL/SW W/O THRL/
P-SW
Released ON OFF Fully
depressed OFF ON
Accelerator
pedal
condition Voltage
Terminal No. q
16Terminal No.
q17
Released Battery
voltage 1V or less
Fully
depressed 1V or less Battery
voltage
YAT328
YAT329
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TROUBLE DIAGNOSIS FOR NON-DETECTABLE ITEMS
Park/neutral Position, Overdrive Control or
Throttle (Accelerator) Position Switches
(Cont'd)
AT-96
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1. SPORT Indicator Lamp Does Not Come On
SYMPTOM:
POWER indicator lamp does not come on for about 2 seconds
when turning ignition switch to ªONº.
CHECK TCM POWER SOURCE.
1. Turn ignition switch to ªONº position.(Do not start engine.)
2. Check voltage between TCM terminals q
10,q19and ground.
Battery voltage should exist.
OK
ENG Check the following items:
IHarness for short or
open between ignition
switch and TCM (Main
harness)
I Ignition switch and fuse
Refer to EL section
(ªPOWER SUPPLY
ROUTINGº).
CHECK TCM GROUND CIRCUIT.
1. Turn ignition switch to ªOFFº position.
2. Disconnect TCM harness connector.
3. Check resistance between TCM termi- nals q
25,q48and ground.
Resistance: Approximately 0W
If OK, check harness for short to
ground and short to power.
OK
ENG Repair open circuit or short
to ground or short to
power in harness or con-
nector.
CHECK LAMP CIRCUIT.
1. Turn ignition switch to ªONº position.
2. Set overdrive control, A/T check or power switch to ªONº position.
3. Check voltage between TCM terminal q
13and ground.
Voltage: Battery voltage
4. Reinstall any part removed.
OK
ENG Check the following items:
IFuse (7.5A)
I SPORT indicator lamp
Refer to EL section
(ªWARNING LAMPSº).
I Harness for short or
open between ignition
switch and SPORT indi-
cator lamp (Main har-
ness)
Refer to EL section
(ªPOWER SUPPLY
ROUTINGº).
I Harness for short or
open between SPORT
indicator lamp and TCM
Check again.
OK
ENG
1. Perform TCM input/
output signal inspection.
2. If NG, recheck TCM pin terminals for damage or
loose connection with
harness connector.
INSPECTION END
YAT427
YAT428
YAT429
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DIAGNOSTIC PROCEDURES FOR SYMPTOMS
AT-99
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5. Engine Cannot Be Started In ªPº and ªNºPosition
SYMPTOM:
I Engine cannot be started with selector lever in ªPº or ªNº
position.
I Engine can be started with selector lever in ªDº, ª2º, ª1º
or ªRº position.
Does ªECU INPUT SIGNALSº in
Data Monitor show damage to park/
neutral position switch circuit?
---------------------------------------------------------------------------------------------------------------------- -OR -----------------------------------------------------------------------------------------------------------------------
Does self-diagnosis show damage to
park/neutral position switch circuit?
No
EYe s
Check park/neutral position
switch. Refer to AT-93.
Check for short or open of park/neutral
position switch 2-pin connector. Refer to
AT-93.
OK
ENGRepair or replace park/
neutral position switch.
Check starting system. Refer to EL sec-
tion (ªSystem Descriptionº, ªSTARTING
SYSTEMº).
OK
ENGRepair or replace dam-
aged parts.
INSPECTION END
6. In ªPº Position, Vehicle Moves Forward Or
Backward When Pushed
SYMPTOM:
Vehicle moves when it is pushed forward or backward with
selector lever in ªPº position.
Check parking pawl components. Refer to
AT-180.
OK
ENG Repair or replace dam-
aged parts.
INSPECTION END
SAT146BA
NAT275
SAT133B
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DIAGNOSTIC PROCEDURES FOR SYMPTOMS
AT-102
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16. A/T Does Not Hold Lock-up Condition
SYMPTOM:
A/T does not hold lock-up condition for more than 36 seconds.
Does self-diagnosis show damage to
engine speed signal circuit after cruise
test?
No
EYe sCheck engine speed sig-
nal. Refer to AT-82.
1. Remove oil pan.
2. Check A/T fluid condition.
OK
ENG 1. Remove control valve
assembly. Refer to
AT-118.
2. Check the following items:
I Torque converter clutch
control valve
I Pilot valve
I Pilot filter
3. Disassemble A/T.
4. Check torque converter and oil pump assembly.
1. Remove control valve assembly. Referto AT-118.
2. Check the following items:
I Torque converter clutch control valve
I Pilot valve
I Pilot filter
OKFOK
Check again.
OK
ENG 1. Perform TCM input/
output signal inspection.
2. If NG, recheck TCM pin terminals for damage or
loose connection with
harness connector.
INSPECTION END
17. Lock-up Is Not Released
SYMPTOM:
Lock-up is not released when accelerator pedal is released.
Does ªECU INPUT SIGNALSº in
Data Monitor show damage to closed
throttle position switch circuit?
---------------------------------------------------------------------------------------------------------------------- -OR -----------------------------------------------------------------------------------------------------------------------
Does self-diagnosis show damage to
closed throttle position switch circuit?
No
EYe s
Check closed throttle posi-
tion switch. Refer to AT-93.
Check again.
OK
ENG1. Perform TCM input/
output signal inspection.
2. If NG, recheck TCM pin terminals for damage or
loose connection with
harness connector.
INSPECTION END
SAT835H
SAT171B
SAT146BA
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DIAGNOSTIC PROCEDURES FOR SYMPTOMS
AT-112
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18. Engine Speed Does Not Return To Idle(Light Braking D
4®D3)
SYMPTOM:
I Engine speed does not smoothly return to idle when A/T
shifts from D
4to D3.
I Vehicle does not decelerate by engine brake when turning
overdrive control switch OFF.
I Vehicle does not decelerate by engine brake when shifting
A/T from ªDº to ª2º position.
Does self-diagnosis show damage to
overrun clutch solenoid valve circuit after
cruise test?
No
EYe s
Check overrun clutch sole-
noid valve. Refer to AT-71.
Check throttle (accelerator) position sen-
sor. Refer to EC section [TROUBLE
DIAGNOSIS FOR ªTHROTTLE (ACCEL)
POSI SENº].
OK
ENGRepair or replace throttle
(accelerator) position sen-
sor.
1. Remove oil pan.
2. Check A/T fluid condition.
OK
ENG 1. Remove control valve
assembly. Refer to
AT-118.
2. Check the following items:
I Overrun clutch control
valve
I Overrun clutch reducing
valve
I Overrun clutch solenoid
valve
3. Disassemble A/T.
4. Check the following items:
I Overrun clutch assembly
I Oil pump assembly
1. Remove control valve assembly. Refer
to AT-118.
2. Check the following items:
I Overrun clutch control valve
I Overrun clutch reducing valve
I Overrun clutch solenoid valve
OK
FOK
Check again.
OK
ENG 1. Perform TCM input/
output signal inspection.
2. If NG, recheck TCM pin terminals for damage or
loose connection with
harness connector.
INSPECTION END
YAT338
NAT262
SAT171B
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DIAGNOSTIC PROCEDURES FOR SYMPTOMS
AT-113
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23. A/T Does Not Shift: 22®11, When Selector
Lever ª2º ®ª1º Position
SYMPTOM:
A/T does not shift from 22to 11when changing selector lever
from ª2º to ª1º position.
Does ªECU INPUT SIGNALSº in
Data Monitor show damage to park/
neutral position switch circuit?
---------------------------------------------------------------------------------------------------------------------- -OR -----------------------------------------------------------------------------------------------------------------------
Does self-diagnosis show damage to
park/neutral position switch circuit?
No
EYe s
Check park/neutral position
switch circuit. Refer to
AT-97.
Check again.
OK
ENG1. Perform TCM input/
output signal inspection.
2. If NG, recheck TCM pin terminals for damage or
loose connection with
harness connector.
INSPECTION END
24. Vehicle Does Not Decelerate By Engine
Brake
SYMPTOM:
Vehicle does not decelerate by engine brake when shifting
from 2
2(12)to11.
Is 9. Vehicle Does Not Creep Backward In
ªRº Position OK?
Ye s
ENo Go to 9. Vehicle Does Not
Creep Backward In ªRº
Position, AT-105.
Go to 18. Engine Speed Does Not Return
To Idle (Light Braking D
4,D3), AT-113.
SAT146BA
SAT778B
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DIAGNOSTIC PROCEDURES FOR SYMPTOMS
AT-117
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