General Information
The ESS system collects and relays information pertaining to the positions of the shift-intent and system switches (see Fig.), transmission input and output shaft speeds, and shift lever position. The information is received by the engine Electronic Control Module (ECM) which signals the fuel control system to increase or decrease engine rpm to match road speed. The ECM also controls HI and LO range selection in the auxiliary case on the rear of the transmission.
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Shift-Intent Switch
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System Switch
Fig. 1, ESS Shift Handle
The system switch (see Fig.) is the lower switch located on the driver's side of the shift handle. It controls ESS system operation. When in the down position, the system is operating and the word ON is visible on the switch. In the up position, the word OFF is visible, the system is not operating, and the transmission can be shifted manually.
The shift-intent switch (see Fig.) is the upper switch on the driver's side of the shift handle. It has four positions and controls upshifting and downshifting by communicating to the ECM the driver's intention of changing gears.
Note: If the system switch is OFF, use the shift-intent switch to select between ranges. Push the top of the switch (see Fig.) to select the HI range on upshifts and the bottom of the switch (see Fig.) to select the LO range on downshifts.
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Press the top portion (engage the first position) of the shift-intent switch to begin an upshift.
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Press the top portion again (engage the second position) to break torque.
Fig. 2, ESS Upshifting Using the Shift-Intent Switch
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Press the bottom portion (engage the first position) of the shift-intent switch to begin a downshift.
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Press the bottom portion again (engage the second position) to break torque.
Fig. 3, ESS Downshifting Using the Shift-Intent Switch
Warning: Make sure that the transmission is in neutral (N) when you start the vehicle. If the vehicle is started in gear, it will suddenly move forward or backward which could result in personal injury and damage to property and the transmission.