Toyota ZZT230 series Repair Manual page 457

Dl-246
P0753,P0758
DTC
CIRCUIT DESCRIPTION
Shifting from 1st to 0/D is performed in combination with ON and OFF of the shift solenoid valve No. 1 and
No. 2 controlled by ECM. If an open or short circuit occurs in either of the solenoid valves, the ECM controls
the remaining normal solenoid valve to allow the vehicle to be operated smoothly (Fail safe function).
NORMAL
'
Range
N .
ON
ON OFF
D
OFF
OFF
OFF ON
ON ON
2
ON OFF
OFF
OFF
ON ON
L
ON OFF
X. Malfunchoos
HINT:
Check the sift solenoid valve No. 1 when DTC P0753 is output and check the shift solenoid valve No. 2 when
OTC P0758 is output.
OTCNo.
The ECM checks for an open or short circuit in the shift sole-
nold valve No. 1/No.
The ECM records DTC P0753
detects
detected once, but it does not blink the MIL
After ECM
more in 1-trip, it causes the MIL to light up until condition (a) or
{b)
P0753!62 disappears.
After that, if the ECM detects condition {a) or (b) once, it starts
P0758!63
lighting up MIL again.
(a) Solenoid resistance
solenoid is energized.
is
{b)
Solenoid resistance Is 100
the solenoid not eneroized.
Fatl safe function:
If either of the solenoid valve circuits develops an open or short, the ECM turns the other solenoid valve ON
and OFF to shift to the gear positions shown in the table above. The ECM also turns the shift solenoid valve
STOFF at the same time. If both solenoids malfunction, hydraulic control cannot be performed electronically
and must be done manually.
Manual shifting as shown in the above table must be done (In the case of a short circuit, the ECM stops send­
ing current to the short circuited solenoid).
Shift Solenoid AlB Electrical Malfunc-
tion (Shift Solenoid Valve No. 1 /No. 2
SHIFT SOLENOID VALVE
NO. 1 MALFUNCTIONING
GOM
"'
N .
1
ON
X
OFF
X
X OFF
ON
OlD X
'"
ON
X
OFF
2od X
,,,
'" OFF
X
X
X OFF
DTC Detecting Condition
2
circuli when it changes.
or P075B if condition (a) or
(b) 2
condition (a) or continuously
is 8 !l or
less (short circuit) when the
kn
or more (open circt�it) when
o
SHIFT SOLENOID VALVE
' .
NO. 2 MALFUNCTIONING
I
Gear Gear
'"'
,,, X
ON
OlD
,,, OFF X
X
OFF
OlD
OlD OFF
X OlD
,,,
X
ON
,,,
X
OFF
,,,
'"
OFF
X
X
ON
X
ON
(b)
is
times or
•
•Open or short in shift solenoid valve No. t!No. 2 circuit
Shift soloooid valve No.
•ECM
BOTH SHIFT SOLENOID
VALVES MALFUNCTIONING
Gear when shift selector is
'" manually oOOratad OlD
OlD
OlD
OlD
"'
""
'"'
""
,,,
"'
'"
'"
'" '"
Trouble Area
I !No. 2
)