
DIAGNOSTIC PROCEDURE
CHECK GROUND CIRCUIT.
1. Turn ignition switch to ªOFFº position.
2. Disconnect terminal cord assembly con-
nector in engine compartment.
3. Check resistance between terminalq
2
and ground.
Resistance: 20 - 40W
OK
ENG
1. Remove control valve
assembly. Refer to
AT-113.
2. Check the following
items:
IShift solenoid valve A
Refer to ªCOMPONENT
INSPECTIONº below.
IHarness of terminal cord
assembly for short or
open
CHECK POWER SOURCE CIRCUIT.
1. Turn ignition switch to ªOFFº position.
2. Disconnect TCM harness connector.
3. Check resistance between terminalq
2
and TCM harness connector terminal
q
11.
Resistance:
Approximately 0W
If OK, check harness for short to
ground and short to power.
4. Reinstall any part removed.
OK
ENG
Repair open circuit or short
to ground or short to power
in harness or connector.
Perform ªSELF-DIAGNOSIS CODE CON-
FIRMATION PROCEDUREº, AT-63.
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
COMPONENT INSPECTION
Shift solenoid valve A
IFor removal, refer to AT-139.
Resistance check
ICheck resistance between terminalq
2and ground.
Solenoid valve Terminal No.Resistance
(Approx.)
Shift solenoid
valve Aq
2Ground 20 - 40W
Operation check
ICheck solenoid valve by listening for its operating sound while
applying battery voltage to the terminalq
2and ground.
YAT300
YAT301
YAT302
YAT303
H
H
H
TROUBLE DIAGNOSIS FOR SHIFT SOLENOID/V A
Shift Solenoid Valve A (Cont'd)
AT-64

DIAGNOSTIC PROCEDURE
CHECK GROUND CIRCUIT.
1. Turn ignition switch to ªOFFº position.
2. Disconnect terminal cord assembly con-
nector in engine compartment.
3. Check resistance between terminalq
1
and ground.
Resistance: 20 - 40W
OK
ENG
1. Remove control valve
assembly. Refer to
AT-139.
2. Check the following
items:
IShift solenoid valve B
Refer to ªCOMPONENT
INSPECTIONº below.
IHarness of terminal cord
assembly for short or
open
CHECK POWER SOURCE CIRCUIT.
1. Turn ignition switch to ªOFFº position.
2. Disconnect TCM harness connector.
3. Check resistance between terminalq
1
and TCM harness connector terminal
q
12.
Resistance:
Approximately 0W
If OK, check harness for short to
ground and short to power.
4. Reinstall any part removed.
OK
ENG
Repair open circuit or short
to ground or short to power
in harness or connector.
Perform ªSELF-DIAGNOSIS CODE CON-
FIRMATION PROCEDUREº, AT-66.
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
COMPONENT INSPECTION
Shift solenoid valve B
IFor removal, refer to AT-139.
Resistance check
ICheck resistance between terminalq
1and ground.
Solenoid valve Terminal No.Resistance
(Approx.)
Shift solenoid
valve Bq
1Ground 20 - 40W
Operation check
ICheck solenoid valve by listening for its operating sound while
applying battery voltage to the terminalq
1and ground.
YAT304
YAT305
YAT306
YAT307
H
H
H
TROUBLE DIAGNOSIS FOR SHIFT SOLENOID/V B
Shift Solenoid Valve B (Cont'd)
AT-67

Overrun Clutch Solenoid Valve
DESCRIPTION
The overrun clutch solenoid valve is activated by the TCM in
response to signals sent from the park/neutral position switch, over-
drive control switch, vehicle speed and throttle (accelerator) posi-
tion sensors. The overrun clutch operation will then be controlled.
ON BOARD DIAGNOSIS LOGIC
Diagnostic trouble code Malfunction is detected when ...Check items
(Possible cause)
: OVERRUN CLUTCH S/V
TCM detects an improper voltage drop
when it tries to operate the solenoid
valve.IHarness or connectors
(The solenoid circuit is open or
shorted.)
IOverrun clutch solenoid valve
: 6th judgement flicker
SELF-DIAGNOSIS CODE CONFIRMATION PROCEDURE
After the repair, perform the following procedure to confirm the
malfunction is eliminated.
1) Start engine.
2) Select ªSELF-DIAG RESULTSº mode with CONSULT-II.
3) Drive vehicle under the following conditions:
Selector lever in ªDº position, overdrive control switch in
ªOFFº position and vehicle speed higher than 10 km/h (6
MPH).
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Start engine.
2) Drive vehicle under the following conditions:
Selector lever in ªDº position, overdrive control switch in
ªOFFº position and vehicle speed higher than 10 km/h (6
MPH).
3) Perform self-diagnosis.
Refer to SELF-DIAGNOSTIC PROCEDURE (Without
CONSULT-II), AT-15.
SAT341H
YAT351
TROUBLE DIAGNOSIS FOR OVERRUN CLUTCH S/V
AT-69

DIAGNOSTIC PROCEDURE
CHECK GROUND CIRCUIT.
1. Turn ignition switch to ªOFFº position.
2. Disconnect terminal cord assembly
connector in engine compartment.
3. Check resistance between terminalq
3
and ground.
Resistance: 20 - 40W
OK
ENG
1. Remove control valve
assembly. Refer to
AT-113.
2. Check the following items:
IOverrun clutch solenoid
valve
Refer to ªCOMPONENT
INSPECTIONº below.
IHarness of terminal cord
assembly for short or open
CHECK POWER SOURCE CIRCUIT.
1. Turn ignition switch to ªOFFº position.
2. Disconnect TCM harness connector.
3. Check resistance between terminalq
3
and TCM harness connector terminal
q
20.
Resistance:
Approximately 0W
If OK, check harness for short to
ground and short to power.
4. Reinstall any part removed.
OK
ENG
Repair open circuit or short
to ground or short to power
in harness or connector.
Perform ªSELF-DIAGNOSIS CODE
CONFIRMATION PROCEDUREº, AT-69.
OK
ENG
1. Perform TCM input/output
signal inspection.
2. If NG, recheck TCM pin
terminals for damage or
loose connection with har-
ness connector.
INSPECTION END
COMPONENT INSPECTION
Overrun clutch solenoid valve
IFor removal, refer to AT-113.
Resistance check
ICheck resistance between terminalq
3and ground.
Solenoid valve Terminal No.Resistance
(Approx.)
Overrun clutch
solenoid valveq
3Ground 20 - 40W
Operation check
ICheck solenoid valve by listening for its operating sound while
applying battery voltage to the terminalq
3and ground.
YAT308
YAT309
YAT310
YAT311
H
H
H
TROUBLE DIAGNOSIS FOR OVERRUN CLUTCH S/V
Overrun Clutch Solenoid Valve (Cont'd)
AT-70

Torque Converter Clutch Solenoid Valve
DESCRIPTION
The torque converter clutch solenoid valve is activated, with the
gear in D
4, by the TCM in response to signals sent from the vehicle
speed and throttle (accelerator) position sensors. Torque converter
clutch piston operation will then be controlled.
Lock-up operation, however, is prohibited when A/T fluid tempera-
ture is too low.
ON BOARD DIAGNOSIS LOGIC
Diagnostic trouble code Malfunction is detected when ...Check items
(Possible cause)
: T/C CLUTCH SOL/V
TCM detects an improper voltage drop
when it tries to operate the solenoid
valve.IHarness or connectors
(The solenoid circuit is open or
shorted.)
IT/C clutch solenoid valve
: 7th judgement flicker
CONSULT-II REFERENCE VALUE IN DATA MONITOR MODE
Remarks: Specification data are reference values.
Monitor item Condition Specification
Torque converter clutch solenoid valve
dutyLock-up ªOFFº
"
Lock-up ªONºApproximately
4%
"
Approximately
94%
SELF-DIAGNOSIS CODE CONFIRMATION PROCEDURE
After the repair, perform the following procedure to confirm the
malfunction is eliminated.
1) Start engine.
2) Select ªSELF-DIAG RESULTSº mode with CONSULT-II.
3) Drive vehicle in D
1,D2,D3,D4,D4lock-up
position.
------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------OR------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
1) Start engine.
2) Drive vehicle in D
1,D2,D3,D4,D4lock-up
position.
3) Perform self-diagnosis.
Refer to SELF-DIAGNOSTIC PROCEDURE (Without
CONSULT-II), AT-15.
SAT342HA
SAT818H
TROUBLE DIAGNOSIS FOR T/C CLUTCH SOL/V
AT-72

DIAGNOSTIC PROCEDURE
Perform diagnostic test mode II (self-
diagnostic results) for engine control.
Check ignition signal circuit condition.
OK
ENG
Check ignition signal circuit
for engine control. Refer to
EC section [TROUBLE
DIAGNOSIS FOR ªIGN
SIGNAL-PRIMARYº (DTC
21)].
CHECK INPUT SIGNAL.
1. Start engine.
2. Select ªECU INPUT SIGNALSº in
Data Monitor.
3. Read out the value of ªENGINE
SPEEDº.
Check engine speed changes
according to throttle position.
-----------------------------------------------------------------------------------------------------------------------OR -----------------------------------------------------------------------------------------------------------------------
1. Start engine.
2. Check voltage between TCM ter-
minalq
39and ground.
Voltage (Idle speed):
Approximately 0.8V
Voltage (2,000 rpm):
Approximately 2.2V
OK
ENG
Check the following items:
IHarness for short or
open between TCM and
ECM
IResistor
Refer to EC section
[TROUBLE DIAGNOSIS
FOR ªIGN SIGNAL-PRI-
MARYº (DTC 21)].
Perform ªSELF-DIAGNOSIS CODE CON-
FIRMATION PROCEDUREº, AT-80.
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
YAT320
H
H
H
TROUBLE DIAGNOSIS FOR ENGINE SPEED SIG
Engine Speed Signal (Cont'd)
AT-81

DIAGNOSTIC PROCEDURE
CHECK GROUND CIRCUIT.
1. Turn ignition switch to ªOFFº position.
2. Disconnect terminal cord assembly
connector in engine compartment.
3. Check resistance between terminalq
4
and ground.
Resistance: 2.5 - 5W
OK
ENG
1. Remove control valve
assembly. Refer to
AT-113.
2. Check the following
items:
ILine pressure solenoid
valve
Refer to ªCOMPO-
NENT INSPECTIONº
on next page.
IHarness of terminal
cord assembly for
short or open
CHECK POWER SOURCE CIRCUIT.
1. Turn ignition switch to ªOFFº position.
2. Disconnect TCM harness connector.
3. Check resistance between terminalq
4
and TCM harness connector terminal
q
2.
Resistance: 11.2 - 12.8W
OK
ENG
Check the following items:
IDropping resistor
Refer to ªCOMPONENT
INSPECTIONº on next
page.
IHarness for short or
open between TCM ter-
minalq
2and terminal
cord assembly (Main
harness)
CHECK POWER SOURCE CIRCUIT.
1. Turn ignition switch to ªOFFº position.
2. Check resistance between terminalq
6
and TCM harness connector terminal
q
1.
Resistance:
Approximately 0W
If OK, check harness for short to
ground and short to power.
3. Reinstall any part removed.
OK
ENG
Repair open circuit or short
to ground or short to
power in harness or con-
nector.
Perform ªSELF-DIAGNOSIS CODE CON-
FIRMATION PROCEDUREº, AT-84.
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
YAT321
YAT322
H
H
H
H
TROUBLE DIAGNOSIS FOR LINE PRESSURE S/V
Line Pressure Solenoid Valve (Cont'd)
AT-85

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-
minalsq
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-114.
IHarness for short or
open between ignition
switch and park/neutral
position switch (Main
harness)
IHarness for short or
open between park/
neutral position switch
and TCM (Main harness)
IDiode
qA
(Go to next page.)
Lever positionTerminal No.
q36q35q34q27q26
P, NB0000
R0B000
D00B00
2 000B0
1 0000B
YAT326
H
TROUBLE DIAGNOSIS FOR NON-DETECTABLE ITEMS
Park/neutral Position, Overdrive Control or
Throttle (Accelerator) Position Switches
(Cont'd)
AT-89