DRIVING - Up or Down Shifting The instument cluster will illuminate with the corresponding gear. LOW Mode LOW mode should be used any time you want to maximize engine braking and minimize the use of the brake pedal. For example, when driving down long grades or when coming to a stop. Selects lowest available gear for start gear. The starting gear cannot be changed in LOW mode. WARNING 2 On slippery surfaces minimize engine braking in LOW mode. Excessive en- gine braking at higher engine RPM could cause a loss of traction and vehi- cle control.
NOTE Gear Display If the driver attempts to select a non- neutral mode without depressing the service brakes the transmission will not shift into gear. The driver must re-select Neutral and depress the service brakes before selecting the desired mode again. How to Deactivate MAX Mode If LOW is selected while moving, the transmission will not upshift (except for the Transmission Override conditions noted on the previous page). The transmission system will downshift at the earliest opportunity to enable higher than normal engine RPM to provide maximum engine braking. Vehicles with automated transmissions will have the engine brake function integrated with the transmission controls.
Follow these steps to deactivate MAX engine brake mode. 1. Accelerate with the throttle pedal. 2. Upshift, see Up or Down Shifting on page 15. 3. Wait for the transmission coast down gear to engage. 16 Y53-1272-1B1 (08/17) NOTE The PACCAR Automated Transmission initiates upshifts from MANUAL and LOW for engine overspeed protection.