Sta Signal; Nsw Signal - Toyota COMPUTER-CONTROLLED SYSTEM Training Manual

ELECTRONIC
CONTROL SYSTEM - STA Signal, NSW Signa l
STA (STARTER) SIGNA L
This signal is used to judge if the engine is being
cranked . Its main function is to allow the Engine
ECU to increase the fuel injection volume during
cranking . As can be understood from the figure
below, the STA signal is voltage the same
voltage as that supplied to the starter motor .
ELECTRICAL CIRCUITRY
Ignition (M/T )
switch
Engine EC U
OHP 34
NSW (NEUTRAL START
SWITCH) SIGNAL
In vehicles with an automatic transmission or
transaxle, this signal is used by the Engine ECU
to determine whether the shift lever is in the
"P" or "N" position, or in some other position .
The NSW signal is used mainly in controlling the
ISC system .
ELECTRICAL CIRCUITRY
Engine EC U
OHP 3 4
REFERENCE
1 . The Engine ECU judges whether th e
engine is cranking based on the STA
signal . There are also engines which use
the NE signal to judge the engine running
conditions during starting .
2 . In some engine models, if the STA signal
is input while the engine is running, it
could result in the engine stalling .
1 . When the ignition switch is in the START
position, ba tt e ry voltage is supplied to the
NSW terminal .
2 . When the ignition switch is in a position
other than START, and the neutral sta rt
switch is open ( i .e ., the transmission is in
"L", "2", "D" or "R"), the voltage at the
NSW terminal is high .
3 . When the ignition switch is in a position
other than START, and the neutral sta rt
switch is closed (i .e ., the transmission is in
"P" or " N"), the voltage at the NSW
terminal is low due to the electrical load
at the sta rt er motor, etc .
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