TRANSMISSION AR 4223795 - Caterpillar

Throttle Backup Control
Illustration 1 g00639333
Illustration 2 g00639380
Automatic Engine Speed Control (AESC) (switch) (1) can be used as a throttle backup control for engine speed control (dial) (2). If the Electronic Control Module (ECM) cannot read the setting of the engine speed dial, the following events occur automatically:
The engine speed is held at the last known value that was read from engine speed dial (2) until AESC switch (1) is pressed.
An error message is displayed by the Vital Information Management System (VIMS).
The engine speed dial is disabled until the engine is powered down.
The AESC system is activated. The AESC system remains activated until the engine is powered down.
AESC switch (1) has no effect on the AESC system until the engine is powered down. The AESC switch is used as a throttle backup control instead.Press the top of AESC switch (1) in order to set the engine speed at high idle (1830 rpm). Press the bottom of the AESC switch in order to set the engine speed at low idle (725 rpm).Hydraulic Backup Control (If Equipped)
Illustration 3 g00639470
If hydraulic power is lost due to malfunction of the pump control, hydraulic backup control (switch) (3) sets the stroke of the pumps to a limited preset value. This allows the machine to operate with reduced capabilities.Hydraulic backup control (switch) (3) is located under the cover at the rear of the left console. Open the cover and lift the red guard. Move the switch to the ON position in order to bypass the hydraulic pump control. This sets the stroke of the implement pump to the preset value.