OM3024.3 8/00 Operation - Section 3 Instrument Panel and Indicators Page 3-27 Automatic Idle Selector Switch (AISS) ASR Cut (Traction Control) Switch (Option) The AISS Switch (3, Figure 3-10) 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 Quantum Fuel Control System for a “low idle” RPM. The ASR cut switch (5, Figure 3-10) is used to activate or de-activate the Op- tional traction control system. The “rocker” switch is an “ON-OFF” type. Depressing the bottom turns the system “Off”. Depressing the top turns the system “On”.
When the system is On, the internal lamp in the switch illuminates. This signal may be for either: 650 RPM - “Normal” low idle, or 1000 RPM - High-Low idle; depending on the following conditions: 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. When ASR is active, the system monitors individual wheel speeds and if it determines one of the rear wheels is slipping (losing traction) when power is applied, braking is applied to the rear wheel with the higher speed. 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. NOTE: If both rear wheels are slipping approximately the same amount, the system will not provide any braking to the wheels. In this situation, the operator must reduce the throttle to prevent slippage. If the engine coolant temperature is above 30°C/47°F, the PMC will signal for 650 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. 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 con- ditions. “On/Low position is used when fine con- trol movements are needed, such as when parking in confined spaces. Air Conditioner & Heater Vent The air conditioner/heater vent (4, Figure 3-10) 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.