Section 10 --- Chassis Information
The Executive 2005
490
The engine brake will not be active when:
• Engine speed goes below 850 RPM.
• An electronic fault code is active.
Applying the service brakes will disengage the cruise control. Activating the Jake Brake foot switch
will disengage the cruise control and activate the engine brake and brake lights. Use the engine brake
when traveling down a hill, on the freeway or exiting the off ramp. The engine brake will allow the
engine temperature to decrease while going downhill.
NOTE:
Idle the engine three to five minutes at approximately 1000 RPM to warm the
engine before activating the engine brake. Do not operate the engine brake until
the engine oil temperature is above 30º C (86º F).
WARNING:
The engine brake is designed to assist the motorhome service brakes. Not for
stopping.
TRANSMISSION - Shift Selector
The Allison World transmission incorporates the World Transmission
Electronic Control (WTEC) system. The system is compromised of five
major components connected by a wiring harness: the electronic control
unit (ECU), engine throttle position sensor, three speed sensors, remote shift
selector (keypad) and the control module. The ECU processes information
received from the throttle position sensor, speed sensor, pressure switch
and shift selector to activate solenoids on the control module in the trans-
mission. The solenoids control oncoming and off going clutch pressure to
provide closed loop shift control. This is accomplished by matching trans-
mission and engine RPM during a shift to establish a desired shift profile
within the ECU.
The system is monitored for the first 30 seconds of each engine start.
This is referred to as “auto-detect.” Auto-detect searches for presence of
data inputs of transmission components. Auto-detect enables the ECU func-
tions and diagnostics to respond to items that are detected.
Another feature of the transmission is the ability to “learn” or “adapt.”
The electronic control system optimizes shift quality by using “Adaptive
Shifting.” A wide variety of varied shift conditions is required before opti-
mizing shift quality. Generally, five typical shifts of a consistent shift type
is needed to optimize shift quality.
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