Toyota ZZT230 series, Repair Manual

Page: 476 / 821

)
m-265
DIAGNOSTICS
AUTOMATIC TRANSAXLE
--
DTC
P1790 ST Solenoid Valve Circuit Malfunction
CIRCUIT DESCRIPTION
Shift solenoid valve ST is switched
ON-OFF
by a signal from ECM so that let in or out timing of 2nd
brake
is adjusted by operating orifice control valve. Therefore, ST solenoid operates when letting in or out
reverse
clutch.
If it is
broken, the shift shock becomes big.
DTCNo.
ore Detecting Concition Trouble
Area
ECU mernorizes
DTC
P1790
if
(a)
or (b)
condition below
Is
delecledonce or
more,
bul ECU
does not
start
MIL blnking.
•Open
Of
short in shift solenoid valve ST
circuit
(a)
Solenoid resistance is 30 0
or lower
{short circuit) when
P1790
solenoid
energized.
•Shift solenoid valve ST
(b)
Solenoid
resistanoe
Is 100
kn. or higher
(open
Circuit) when
•MIL
solenoid is not
energized.
WIRING DIAGRAM
Transaxle
ECM
Shift Solenoid
Valve ST
BR-W
ST
c