CRUISE CONTROL OPERA TION

Speed Control Switches

Note: fective August a change was made the vehicle software which requires the vehicle operator press and release the brake pedal after the engine has been the brake pedal not depressed after starting the cruise control will not function.

Resume/Set Switch — Allows the driver set and resume cruise control.

Note: most cases, the Speed Control switch must the position order use the Resume/Set However , when the Initial Set Using Resume Switch feature enabled, cruise control can activated using the Resume/Set switch.

The Resume/Set switch also functions the Accel/Decel switch. Usually the Resume position (press the top) corresponds increase engine speed (Accel) and the Set position (press the bottom) corresponds a decrease engine speed (Decel).

Note: Under specific circumstances this switch can also used activate cruise For details concerning the Initial Set Using Resume Switch refer the V - MAC Support Softwar e User ’ s Guide .

Speed Control Switch — Activates the cruise control system.

the desired press and release the Resume/Set This speed now programmed and will automatically

Note: T o increase the engine speed, press and hold the Accel switch until the desired speed attained, press the accelerator pedal until the desired speed attained and then press and release the Set

Disengaging Cruise Control

T o turn f the cruise control system, move the Speed Control switch the OFF position.

Note: the Speed Control switch moved the OFF position, the process setting cruise control must repeated order - activate cruise control (unless the Initial Set Using Resume Switch feature enabled).

T o temporarily disengage cruise control, disengage the clutch apply the service brakes.

Note: cruise control temporarily disengaged using the clutch service press the Resume switch resume the previously programmed https://www.truck-manuals.net/mack/

MACK POWERLEASH™ ENGINE BRAKE (IF EQUIPPED)

Engines may equipped PowerLeash™ upgradeable. These engines will equipped with PowerLeash™ camshaft. These engines are identified the engine information sticker .

your vehicle equipped with the MACK PowerLeash™ Engine important that you take the time become familiar with your engine brake before putting into

W Arning

Operation any vehicle wet slippery r oads r equir extr eme caution. Because the engine brake converts the engine a r etarding device, should NOT used wet slippery r oads the vehicle has a single driving axle has tandem driving axles that e lightly loaded. Use engine brake under these conditions can cause the vehicle skid a combination vehicle jackknife.

Engine Brake Switch

The Engine Brake switch located the dashboard. The Engine Brake switch a three - position switch located the instrument panel.

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T o operate the vehicle without the engine brake active, leave the dash - mounted switch the OFF position.

The V - MAC® system events engine brake activation the oil temperatur e below 55°C (131°F). The driver should alert the fact that the engine brake will not function until sufficient warm - time has r egar dless the dash switch

How the Engine Brake Activated

When the engine brake (switch either LOW HIGH your engine V - MAC® electronic control system commands engine brake power (engine brake only when the following conditions are true:

• The foot - operated engine accelerator pedal not depressed.

• The clutch pedal not depressed (manual shift transmissions

• The engine speed least 900 rpm.

• V ehicle must gear the engine brake the engine brake will automatically deactivated depressing either the accelerator the the engine speed drops below 900 soon all the engine brake conditions are again true (taking your foot f the accelerator , for the engine brake will again order disable the engine simply return the dash - mounted control switch the OFF

• V ehicle speed should greater than 8 km/h (5mph).

Danger

The engine brake should never considered a substitute for the vehicle service brakes. The service brakes should always maintained good working order , and should always viewed the primary vehicle slowing system. Service brakes are always used bring the vehicle a complete stop.

Cruise Control with the MACK

Engine Brake

When the MACK PowerLeash™ Engine Brake enabled the same time your V - MAC® cruise control the engine brake automatically activates when necessary slow the vehicle the cruise set point Y can select one two possible options:

• The engine brake activated 2 mph above the cruise set point.

• The engine brake activated soon cruise control commands fueling zero (vehicle has just reached cruise set point and fuel has been turned https://www.truck-manuals.net/mack/

The first option the more popular choice for highway use and the default Consult your V - MAC® Operator ’ s Manual for more information about this Y our local MACK dealer can change the current

The engine s ability control maximum vehicle speed limited the selected retarding power the engine brake. the engine brake dash - mounted control switch set the LOW position, only half the available braking power used. the dash - mounted control switch set the HIGH position, the cruise control invokes full engine brake power .

Note: Deactivating the cruise control function does not disable the engine brake.

The MACK PowerLeash™ Engine Brake may activated deactivated other vehicle systems such ABS and Headway control systems. Refer the literature concerning these systems for additional information.