The operator's station for the "C" Series Off-highway Trucks has been changed to improve operator comfort and ergonomics. The "C" Series cab now resembles the cab used on the smaller "D" Series Off-highway Trucks.
The VIMS controls the Truck Payload Measurement System (TPMS) on the 785C and 789C trucks. There are two sets of TPMS external loading lamps on the truck. One set of lamps is on the left side of the cab (arrow) and the other set is on the right platform. The lamps are green and red. The lamps inform the loader operator of the loading progress toward a target payload weight (set through the VIMS Keypad). The lamps are active only during the loading cycle and are off at all other times.
During loading, the green (continue loading) lamps will be ON until the payload is 95% of the target weight setting. Then, the red (stop loading) lamp will light. A "last pass" indication can be programmed into the system using the VIMS Keypad. With last pass indication, the VIMS calculates an average loader pass size and predicts payload weight. If the predicted weight after the NEXT loader pass will be above 95% of the target weight setting, the red lamps FLASH.
The red lamps will be ON continuously after the last pass (when fully loaded).
A minimum of three loader passes are required for the "last pass" indication option to function correctly.
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Shown is a view of the operator's seat and the trainer's seat. The seats are more comfortable with improved seat adjustments.
The trainer's seat has more leg room and can be replaced with an attachment air suspension seat.
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The "C" Series truck hoist system is electronically controlled. The hoist control lever (arrow) activates the four positions of the hoist control valve. The four positions are: RAISE, HOLD, FLOAT, and LOWER.
A fifth position of the hoist valve is called the SNUB position. The operator does not have control over the SNUB position. The body position sensor (see Visual No. 129) controls the SNUB position of the hoist valve. When the body is lowered, just before the body contacts the frame, the Transmission/Chassis ECM signals the hoist solenoids to move the hoist valve spool to the SNUB position. In the SNUB position, the body float speed is reduced to prevent hard contact of the body with the frame.
The truck should normally be operated with the hoist lever in the FLOAT position. Traveling with the hoist in the FLOAT position will make sure the weight of the body is on the frame and body pads and not on the hoist cylinders. The hoist valve will actually be in the SNUB position.
If the transmission is in REVERSE when the body is being raised, the hoist lever sensor is used to shift the transmission to NEUTRAL. The transmission will remain in NEUTRAL until:
1. The hoist lever is moved into the HOLD or FLOAT position; and 2. the shift lever has been cycled into and out of NEUTRAL.
NOTE: If the truck is started with the body raised and the hoist lever in FLOAT, the lever must be moved into HOLD and then FLOAT before the body will lower.
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Shown is an overall view of the dash from the left side of the cab. Some of the improvements are:
- Telescopic/tilt steering column for individual adjustment
- Intermittent wiper/washer, turn signal control and dimmer switch - Enhanced instrument layout
- Backlit rocker switches
- Steering wheel mounted electric horn control 39
The operator controls to the left of the steering column are:
- Telescopic/tilt steering column adjustment lever (1): Push for telescoping and pull for tilt - Intermittent wiper/washer, turn signal control and dimmer switch (2)
- Steering wheel mounted electric horn control (3)
- Cigarette lighter (4): The cigarette lighter socket receives a 12-Volt power supply. This socket can be used as a power supply for 12-Volt appliances. Another 12-Volt power port is provided behind the operator's seat.
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Shown is a closer view of the intermittent wiper/washer, turn signal control and dimmer switch.
Windshield washer: Push the button at the end of the lever to activate the electrically powered windshield washer.
Intermittent wiper switch (six positions):
- OFF (0)
- Intermittent position 1 (one bar) - Intermittent position 2 (two bars) - Intermittent position 3 (three bars) - Low speed continuous wiper (I) - High speed continuous wiper (II)
Dimmer switch: Pull the lever toward the operator for BRIGHT lights, and push the lever away from the operator for DIM lights.
Turn signals: Lift the lever for a RIGHT turn, and lower the lever for a LEFT turn.
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Located on the right side of the steering column is the manual retarder lever. The manual retarder lever is used to modulate engagement of the service brakes on all four wheels. The retarder system allows the machine to maintain a constant speed on long downgrades. The retarder will not apply all of the normal braking capacity.
Located on the dash to the right of the retarder lever are (from left to right):
- Key start switch
- Temperature variable knob - Fan speed switch
NOTICE
Do not use the retarder control as a parking brake or to stop the machine.
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Located on the floor of the cab are:
- Secondary brake pedal (1): Used to modulate application of the parking brakes on all four wheels.
- Service brake pedal (2): Used to modulate engagement of the service brakes on all four wheels. For more precise modulation of the service brakes, use the manual retarder lever on the right side of the steering column.
- Throttle pedal (3): A throttle position sensor is attached to the throttle pedal. The throttle position sensor provides the throttle position input signals to the Engine ECM.
NOTE: The throttle position must be programmed to the 10 to 90% setting. The earlier trucks must be programmed to a 10 to 50% throttle position. The setting is changed in the Engine ECM configuration screen with ET.
The Engine ECM provides an elevated engine idle speed of 1300 rpm when the engine coolant temperature is below 60°C (140°F). The rpm is gradually reduced to 1000 rpm between 60°C (140°F) and 71°C (160°F). When the temperature is above 71°C (160°F), the engine will idle at LOW IDLE (700 rpm).
Increasing the low idle speed helps prevent incomplete combustion and overcooling. To
temporarily reduce the elevated idle speed, the operator can release the parking brake or depress the throttle momentarily, and the idle speed will decrease to LOW IDLE for 10 minutes.
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To the right of the operator's seat is the shift console. Located on the shift console are the transmission shift lever (1) and the parking brake air valve (2).
The "C" Series truck transmissions have SIX speeds FORWARD and ONE speed REVERSE.
The top gear limit and body up gear limit are programmable through the Transmission/Chassis ECM. The top gear limit can be changed from THIRD to SIXTH. The body up gear limit can be changed from FIRST to THIRD.
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Located in the overhead panel are several switches:
- Hazard lights (1)
- Headlights and parking/taillights (2) - Fog lights (3)
- Back-up lights (4)
- Front flood/ladder lights (5)
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Shown is the circuit breaker panel located behind the operator's seat. The previous "B" Series trucks used fuses to protect many of the electrical circuits. The "C" Series trucks use only circuit breakers to protect the electrical circuits.
A 12-Volt/5 amp power port (1) provides a power supply for 12-Volt appliances, such as a laptop computer.
A laptop computer with the VIMS software installed can be connected to the diagnostic connector (2) to obtain diagnostic and production information from the VIMS Electronic Control.
A laptop computer with the Electronic Technician (ET) software installed can be connected to the CAT Data Link connector (3) to obtain diagnostic information and perform programming functions on all the electronic controls.
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Shown is the center of the front dash panel. Eight dash indicators, the four-gauge cluster module, and the speedometer/tachometer module are visible.
The four dash indicators to the left of the four-gauge cluster module are (from top to bottom):
- Left turn
- Body up: Lights when the body is up. Input is from the body position sensor.
- Reverse: Lights when the shift lever switch is in REVERSE.
- High beam
The four dash indicators to the right of the speedometer/tachometer module are (from top to bottom):
- Right turn
- Action lamp: Lights when a Category 2, 2-S, or Category 3 Warning is active.
- Retarder: Lights when the retarder is ENGAGED (Auto or Manual). Flashes rapidly when a fault in the ARC system is detected.
- TCS: Lights when the Traction Control System (TCS) is ENGAGED.
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- Engine coolant temperature: Maximum operating temperature is 107° C (225° F).
- Brake oil temperature: Maximum operating temperature is 121° C (250° F).
- System air pressure: Minimum operating pressure is 450 kPa (65 psi).
- Fuel level: Minimum operating levels are 15% (Category 1) and 10% (Category 2).
The three systems monitored by the speedometer/tachometer module are:
- Tachometer: Displays the engine speed in rpm.
- Ground speed: Displayed in the left side of the three-digit display area and can be displayed in miles per hour (mph) or kilometers per hour (km/h).
- Actual gear: Displayed in the right side of the three-digit display area and consists of two digits that show the actual transmission gear that is engaged. The left digit shows the actual gear (such as "1," "2," etc.). The right digit shows the direction selected ("F," "N" or
"R").
To the right of the Speedometer/Tachometer Module are several rocker switches. The rocker switches control the following systems:
Top row (from left to right)
- Throttle back-up: Raises the engine speed to 1300 rpm if the throttle sensor signal is invalid.
- Ether starting aid: Allows the operator to manually inject ether if the engine oil
temperature is below 10°C (50°F) and engine speed is below 1900 rpm. The manual ether injection duration is five seconds (see Visuals No. 66 and 90).
- ARC: Activates the Automatic Retarder Control (ARC) system.
- Brake release/hoist pilot: Used to release the parking brakes for towing and provide hoist pilot oil to lower the body with a dead engine. The small latch must be pushed UP before the switch can be pushed DOWN.
- TCS test: Tests the Traction Control System (TCS). Use this switch when turning in a tight circle with the engine at LOW IDLE and the transmission in FIRST GEAR. The brakes should ENGAGE and RELEASE repeatedly. The test must be performed while turning in both directions to complete the test.
Bottom row (from left to right)
- Panel Lights: Use this switch to DIM the panel lights
- Air Conditioning: Use this switch to turn ON the air conditioner.
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Shown is the Vital Information Management System (VIMS) message center module (1) and the keypad module (2).
The message center module consists of an alert indicator, a universal gauge, and a message display window. The alert indicator flashes when a Category 1, 2, 2-S, or 3 Warning is present.
The universal gauge displays active or logged data (machine) and maintenance (system) events. The universal gauge will also display the status of a sensor parameter selected for viewing by depressing the GAUGE key on the keypad.
The message display window shows various types of text information to the operator, depending on the menu selected with the keypad. An active event will override most displays until
acknowledged by depressing the OK Key.
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awareness. The second category states that the operation of the machine and the maintenance procedure of the machine must be changed. The third Warning Category states that the machine must be safely shut down immediately.
Warning Category 1
For a Category 1 Warning, the alert indicator will flash. The universal gauge may display the parameter and a message will appear in the message display window. A Category 1 Warning alerts the operator that a machine system requires attention. The "OK" key on the keypad can be used to acknowledge the warning. Some warnings will be silenced for a predetermined period.
After this time period, if the abnormal condition is still present, the warning will reappear.
Warning Category 2
For a Category 2 Warning, the alert indicator and the action lamp will flash. The universal gauge may display the parameter and a message will appear in the message display window.
A Category 2 warning alerts the operator that a change in machine operation is required to avoid possible damage to the indicated system. The "OK" key on the keypad can be used to acknowledge the warning. Some warnings will be silenced for a predetermined period. After this time period, if the abnormal condition is still present, the warning will reappear.
Warning Category 2-S
For a Category 2-S Warning, the alert indicator and the action lamp will flash and a continuous action alarm will sound, which indicate a SEVERE Category 2 Warning. The universal gauge may display the parameter and a message will appear in the message display window. A
Category 2-S Warning alerts the operator to immediately change the operation of the machine