INSULATION GP-HEAT 2Q7149 - Caterpillar

Illustration 1 g00631236
Location of Transmission Hold ControlThe transmission hold control is activated by a toggle switch on the transmission control. The transmission hold control has two purposes. Maintaining the transmission in a selected speed is the primary purpose of the transmission hold control. When the transmission hold control is in the OPEN position, the transmission upshifts at an engine speed of approximately 2000 rpm and downshifts at an engine speed of approximately 1400 rpm. When the transmission hold control is in the CLOSED position, the electronic programmable transmission control (EPTC II) receives an electrical ground through the switch to Pin 8. When the electrical ground contacts Pin 8, the EPTC II is informed about maintaining the current transmission speed. The current transmission speed will be maintained until the transmission hold control is deactivated. When the transmission hold control is in the CLOSED position, there is protection from allowing the speed to drop. The transmission hold control will not allow the EPTC II to downshift if the engine rpm lowers below 1000 rpm.Checking the 15 lights on the EPTC II is the secondary purpose of the transmission hold control. This occurs when the transmission hold control is in the CLOSED position. All of the 15 lights must activate when the transmission hold control is in the CLOSED position. When the lights fail to activate, the circuit for the transmission hold control or the EPTC II is not functioning properly.