Toyota COMPUTER-CONTROLLED SYSTEM Training Manual page 105

ESA - Functions of Engine ECU
4W
~2 Corrective ignition advance contro l
WARM-UP CORRECTIO N
The ignition timing is advanced to improve
drivability when the coolant temperature is low .
In some engine models, this correction changes
the advance angle in accordance with the intake
manifold pressure or the intake air volume .
The ignition timing angle is advanced by
approximately 15° by this correction during
extremely cold weather .
OVER-TEMPERATURE CORRECTIO N
To prevent knocking and overheating, the
ignition timing is retarded when the coolant
temperature is
extremely
high .
The ignition timing angle is retarded a maximum
of approximately 5° by this correction .
0
-5
110*
(230)
Coolant temperature °C
('F)
*Depending
on the engine models .
60*
(140 )
Coolant temperature
'C ('F)
*Depending on the engine models .
OHP 6 6
-RELEVANT SIGNAL S
• Coolant temperature (THW )
• Intake manifold pressure (PIM) or intake air
volume (VS, KS or VG )
REFERENCE
In some engine models, the throttle position
(IDL) signal or the engine speed ( NE) signal is
used as the relevant signal for this correction .
RELEVANT SIGNAL
Coolant temperature (THW)
OHP 66
REFERENCE
In some engine models, the following signals
are also used for this correction .
• Intake manifold pressure ( PIM) signal or
intake air volume (VS, KS or VG) signa l
• Engine speed ( NE) signa l
• Throttle position (IDL) signal
etc .
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