DRIVING - Start-Up and Power Down tem is at normal operating range be- fore attempting to start the vehicle. NOTE Start-Up and Power Down For optimal vehicle performance, it is recommended the vehicle be operated in “D” Drive mode. 3. Start the engine. 4. Allow vehicle air system pressure to build to normal operating range. 5. Apply service brake. 2 Start-Up 1. Ensure N , Neutral, is selected on the Transmission Driver Interface Device. Transmission Manual Override If the vehicle is being back-driven and the engine is approaching a higher than normal RPM level, the transmission system will override the MANUAL position and perform an upshift.
NOTE The transmission will not allow the en- gine to crank if a mode other than Neutral is selected, on Transmission Driver Interface Device, when attempt- ing to start the engine. NOTE The transmission initiates upshifts from MANUAL and LOW for engine overspeed protection. 2. Turn the ignition key to “ON” and allow the PACCAR Automated Transmission to power-up. 6. Select the desired mode and starting gear on the Transmission Driver Interface Device. If the start gear is changed and it causes the engine to lug at takeoff, the transmission system will override the MANUAL position and select the best available gear.
NOTE NOTE Engine cranking is delayed until the transmission power-up is complete and the gear display shows a solid N . If Neutral, N , is not shown in the gear display, ensure that the vehicle air sys- The transmission will override inappro- priate start gear selections to avoid driveline damage. 7. Release the vehicle parking brakes. 8. Release service brake and Urge to Move will allow the vehicle to Y53-1272-1B1 (08/17) 19 NOTE If the service brake is not applied while selecting a starting gear, the initial start gear will not be engaged and the driver will have to reselect Neutral and press the brake while re-selecting the desired mode.