C7 and C9 On-Highway Engines Caterpillar

"Low Cruise Control Speed Set Limit"

This parameter defines the lowest vehicle speed that will allow the cruise control to be set. Programming this parameter to the maximum value disables cruise control.

"High Cruise Control Speed Set Limit"

This parameter defines the highest vehicle speed that will allow the cruise control to be set. If a driver attempts to set a vehicle speed higher than this limit, the high cruise control set limit will be the cruise set speed. If this parameter is programmed to a value that is greater than the "Vehicle Speed Limit" parameter, the cruise control switches can be used to exceed the programmed vehicle speed limit.

"Engine Retarder Mode"

This parameter determines the operation of the "Auxiliary Retarder Output" and the "Exhaust Retarder Output" while the cruise control on/off switch is in the ON position, but the engine is not in cruise control. This feature does not determine, and the feature does not allow the operation of the retarder while the engine is in cruise control.

When this parameter is programmed to "Coast", the retarder is enabled only while the service brakes are being applied. The retarder operates with the application and the release of the service brake in the coast mode.

When this parameter is programmed to "Latch", the retarder stays enabled after the service brakes are released. A direct, immediate pressure on the brake pedal latches the retarder in the ON position. The retarder remains enabled until the accelerator pedal is depressed.

When this parameter is programmed to "Manual", the retarder operates independently of the cruise control status.

"Engine Retarder Minimum VSL Type"

This parameter provides two options for the operation of the engine retarder. The available options are "Soft Limit" and "Hard Limit". The default is "Hard Limit". Refer to Illustration 1.

Illustration 1	g01260986
Operation of the engine retarder as the vehicle speed falls below the "Engine Retarder Minimum Vehicle Speed".

"Engine Retarder Minimum Vehicle Speed"

Note: This parameter is not available on C7 engines.

This parameter determines the minimum vehicle speed limit for the engine retarder to turn ON or to remain ON. Below this speed, the ECM will not turn ON the engine retarder unless the vehicle speed is zero.

Programming this parameter to "0" allows the engine retarder to operate at all vehicle speeds. This parameter affects the engine retarder and any auxiliary retarder such as a BrakeSaver.

"Auto Retarder In Cruise"

This parameter defines the vehicle speed in kilometers per hour (km/h) or miles per hour (mph) above the cruise set speed when the engine retarder will be activated. The engine retarder switch must be in the ON position and the cruise control must be set for this feature to operate. This parameter affects the engine while the cruise control is activated.

Programming this parameter to "0" disables this feature.

Note: Some transmissions down shift when the engine retarder engages. The Caterpillar recommended setting for the "Auto Retarder in Cruise" parameter is 8 km/h (5 mph) in order to reduce the constant down shifting.

The "Auto Retarder In Cruise" turns off once the vehicle speed has been reduced by 3 km/h (2 mph).

If "Soft Cruise Control" is programmed to "Yes", the retarder will not come on until the vehicle speed is at least 8 km/h (5 mph) above the cruise set speed.

"Auto Retarder in Cruise Increment"

This parameter determines the vehicle speed above the "High Cruise Control Speed Set Limit" when the engine retarder will be activated.

Programming this parameter to "0" allows the engine retarder to operate in the "High" mode when the vehicle speed reaches the value that is programmed into the "Auto Retarder in Cruise" parameter.

This parameter applies when the cruise control is on. The actual braking level is determined by the settings of the switches for the engine retarder. For example, the retarder will not come on if the retarder is switched off.

"Cruise/Idle/PTO Switch Configuration"

This parameter defines the function of the set/resume switch for "Accel" mode and for "Decel" mode. This parameter affects cruise control mode, idle mode and PTO mode.

"Soft Cruise Control"

"Soft Cruise Control" provides an operating range around the cruise control set speed in order to provide smoother cruise control. "Soft Cruise Control" controls the cruise set speed within the following range:

• 2.5 km/h (1.5 mph) below the set vehicle speed at full load

• 0.8 km/h (0.5 mph) above the set vehicle speed at no load

Illustration 2	g01722396
Soft Cruise control and soft vehicle speed limit

"Adaptive Cruise Control Enable"

This parameter allows an on board radar system to interact with the cruise control. The onboard radar system will adjust the cruise control set speed in order to maintain a particular vehicle following distance when this parameter is set to "Enabled".