Isuzu N-Series. Manual - part 940
Transmission Control System (Smoother) 7A-215
About Shift Clutch Control
Clutch solenoid valves are controlled so fluid pressure
operates the clutch assembly piston, which operates the
gearshift clutch to disengage and engage the clutch.
The clutch is disengaged while in neutral, and operates
before shifting and after shift control is complete.
When ATF temperature is low (up to 20
°C [68°F]), the
clutch engages in order to warm up the engine.
About Lockup Clutch Control
While running at or above a preset speed, the lockup
clutch engages in order to perform control that
eliminates engine power transmission loss.
• Lockup clutch engagement control
In 2nd and higher gears, the lockup clutch engages
when the following conditions are satisfied: shift
clutch is engaged, input shaft speed is 900 to 1500
rpm (vehicle speed depends on gear position), etc.
In the case of Rev or 1st gear, the lockup clutch
does not engage.
• Lockup clutch disengagement control
The lockup clutch disengages when the following
conditions are satisfied: input shaft speed is 900 to
1500 rpm (input shaft speed depends on gear
position), etc.
About Engine Speed Control
When the clutch is released (for shifting, etc.), a request
for engine speed change is sent to the engine control
module (ECM), and engine blowup and deterioration of
feeling (shift shock etc.) are prevented.
1st Gear Start Control
Turning on the 1st gear start switch causes the normal
start gear (2nd) to change to 1st gear. This can be used
when power is required due to payload and inclines.
Controlled
accelerator
Controlled accelerator
Actual accelerator
Actual accelerator
Required engine speed
Required engine speed
(at gearshift)
Input shaft speed
Input shaft speed
Actual engine speed
Actual engine speed
Low
High
Engaged
Disengaged
T
ransmission speed
Engine speed
Shift clutch control
Shift up control
Shift down control
Acceler
ator
opening angle
N7A2004E