C9 Urban Transit Bus Engine Caterpillar

Idle Parameters

Usage:

C-9 MTB

"Idle Vehicle Speed Limit"

The "Idle Vehicle Speed Limit" is the maximum vehicle speed for setting or maintaining a set engine rpm in the idle mode. In order to enter the idle mode, the engine rpm must be set by the set/resume switch while the cruise control on/off switch is in the ON position. If the vehicle speed signal exceeds this value, the engine will not maintain the set engine rpm.

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Table 1
Minimum	Maximum	Default
2 km/h (1 mph)	24 km/h (15 mph)	2 km/h (1 mph)

"Idle RPM Limit"

The "Idle RPM Limit" is the maximum engine rpm in idle mode. The Idle Mode occurs if the engine rpm is set with the cruise control on/off switch and the set/resume switch. Refer to "Idle Vehicle Speed Limit". The actual high limit of this parameter is determined by the programmed "Top Engine Limit". The lower limit is determined by the programmed "Low Idle Engine RPM".

Programming this parameter to 600 rpm will prevent the engine from idling at a constant rpm above the programmed "Low Idle Engine RPM".

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Table 2
Minimum	Maximum	Default
700 rpm	TEL rpm	TEL rpm

"Idle/PTO RPM Ramp Rate"

The "Idle/PTO RPM Ramp Rate" determines the rate of increase or decrease of engine rpm. This parameter determines rates of increase or decrease in engine rpm for the following functions:

Accel.
Decel.
Resume Idle
PTO

The parameter can be set to a value between 5 rpm and 1000 rpm in one rpm increments.

Note: The parameter affects both idle control and PTO control. The idle mode occurs if the engine rpm is set with the cruise control on/off switch and the set/resume switch. The PTO mode occurs if the engine rpm is set with the PTO on/off switch and the set/resume switch.

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Table 3
Minimum	Maximum	Default
5 rpm/sec	1000 rpm/sec	50 rpm/sec

"Idle/PTO Bump RPM"

The "Idle/PTO Bump RPM" determines the increment or the decrement in engine rpm when the Accel switch or the Decel switch is briefly toggled. The "Idle/PTO Bump RPM" also pertains to the dedicated PTO and idle. If a set speed has been programmed in parameter "PTO Engine RPM Set Speed", the parameter "Idle/PTO Bump RPM" pertains only to the engine speed control that is initiated with the cruise control on/off switch. If a "PTO Engine RPM Set Speed" has been programmed, the "Idle/PTO Bump RPM" does not pertain to the control of the engine rpm that is initiated by utilizing the PTO on/off circuit.

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Table 4
Minimum	Maximum	Default
5 rpm	500 rpm	20 rpm

"Fast Idle RPM 1"

"Fast Idle RPM 1" determines the fast idle engine rpm that is controlled by the fast idle enable switch. Actuating the fast idle switch will cause the engine speed to increase to the programmed value. This rpm can be overridden by the operator. To override the "Fast Idle RPM 1" setting, depress the accelerator pedal until the desired rpm is reached. Once the desired engine rpm is reached, depress the fast idle enable switch. This rpm setting will be the "Fast Idle RPM 1" until the ECM is shut down.

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Table 5
Minimum	Maximum	Default
700 rpm	TEL rpm	1000 rpm

"Fast Idle RPM 2"

"Fast Idle RPM 2" determines the second fast idle engine rpm that is controlled by the fast idle enable switch. The "Fast Idle RPM 2" is disabled by changing the parameter to 0.

If the engine is operating at the "Fast Idle RPM 1" setting, actuating the fast idle enable switch will increase the engine idle speed to the engine speed that is programmed in the "Fast Idle RPM 2" parameter. The fast idle engine rpm will increase if the "Fast Idle RPM 2" parameter is set to a number higher than 0. Actuating the fast idle enable switch for a third time will cause the engine rpm to return to low idle. The engine rpm changes to "Fast Idle RPM 1", "Fast Idle RPM 2", and low idle rpm at a rate that is independent of the value that is programmed in the "Idle/PTO RPM Ramp Rate" parameter.

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