OM3006.3 04/98 Operation - Section 3 Instrument Panel and Indicators Page 3-25 Automatic Idle Selector Switch (AISS) Air Conditioner & Heater Vent The AISS Switch (4, Figure 3-7) controls the ‘‘idle’’ speed of the engine (released throttle pedal). With the foot-operated throttle pedal in the released position, the PMC (Powertrain Management Control- ler) sends a signal to the Centry Fuel Control System for a ‘‘low idle’’ RPM. The air conditioner/heater vent (5, Figure 3-7) swivels on a vertical axis to direct air toward or away from the operator. Air flow (up, down, on, off) through the vent is controlled by manually opening/closing or turning the louver. This signal may be for either:
750 RPM - ‘‘Normal’’ low idle, or 1000 RPM - High-Low idle; depending on the following conditions: Auto Cruise Control (OPTIONAL) The Auto Cruise Control (6, Figure 3-7), if installed, allows the operator to electronically control the truck travel speed. 1. Depressing the bottom of the switch selects the ‘‘Off/AUTO’’ position which is used for normal truck operations. When the AISS switch is in this position, the PMC idle signal will be determined by two conditions: engine coolant temperature, and brake application. a. Engine Coolant Temperature - If the engine coolant temperature is below 30°C/47°F, the PMC will signal for 1000 RPM, regardless of other conditions.
If the engine coolant temperature is above 30°C/47°F, the PMC will signal for 750 RPM, except as follows: b. Brake Application - If both the parking brake and service brake are released (acceleration anticipated), the PMC will signal for 1000 RPM, regardless of other conditions. On/Off Switch This Switch (7, Figure 3-7) selects the On/Off status for the Auto Cruise Control feature. Turning the switch clockwise to the vertical position turns the switch ‘‘On’’. Turning the switch counter-clockwise to the diagonal position turns the switch ‘‘Off’’.
Resume/Accel Switch The Resume/Accel Switch (8, Figure 3-7) is a green, back-lighted switch (power switch ‘‘On’’) that is used to resume a previously pre-selected speed, or to accel- erate/increase to a higher speed. Depressing and re- leasing the switch will increase speed approximately 1 mph (0.62 kph) each time the switch is depressed. 2. Depressing the top of the switch selects the ‘‘On/Low’’ position. When the AISS switch is in this position, the PMC will signal for 750 RPM, regardless of other condi- tions. ‘‘On/Low position is used when fine control movements are needed, such as when parking in confined spaces.
Set/Coast Switch The Set/Coast Switch (9, Figure 3-7) is a green, back- lighted switch (power switch ‘‘On’’) that is used to set the ‘‘Cruise’’ speed when a desired travel speed has been attained. Depressing and releasing the switch will also decrease speed approximately 1 mph (0.62 kph) each time the switch is depressed. Cancel Switch The Cancel Switch (10, Figure 3-7) is a yellow, back- lighted switch (power switch ‘‘On’’) that is used to cancel any speed settings which have been previously selected.