This manual provides information needed to operate and understand the vehicle and its components. More detailed information is contained in the Owner’s Warranty Information for North America booklet, and in the vehicle’s workshop and maintenance manuals.
The instrumentation control unit (ICU) provides the driver with engine and vehicle information. It is comprised of standard and optional gauges, an audible warning, a driver message center, and a lightbar containing warning and indicator lamps (also known as telltales). Warning and indicator lamps illuminate in red (danger), amber (caution), green (status advisory), or blue (high-beam headlights activated).
The diagnostic screens are used by trained technicians to retrieve fault codes and other diagnostic information pertaining to the vehicle. Active faults are current problems that require attention. If active fault codes display during start-up or at any other time, make a note of the fault code and text message, then call an authorized Freightliner service facility for assistance.
During vehicle start-up, with the parking brake set, the ICU4 will display any active fault codes for three seconds each until the parking brake is released. If service cycle screens are enabled and service distance or time has been exceeded, the text SERVICE HOUR/MI (KM) will be displayed to inform the driver that the service interval has been exceeded and vehicle service is required. See Fig. 2.7 for a diagram of the diagnostic and engine display screens. To access the diagnostic screens, press and hold the mode/reset button when the DIAG screen is displayed.
If the word SERVICE appears on the diagnostic message display screen, service cycle screens are enabled. Either service miles or hours can be enabled, but not both. Hold the mode/reset button to display miles or hours remaining until the next scheduled service. If MI (KM) appears on the DIAG screen, service miles are enabled; if HOURS appears on the screen, service hours are enabled. If service miles or hours have been exceeded, the number flashes to indicate service is overdue.
The engine screen displays total engine miles or hours. Press and hold the mode/reset button to display total engine miles. Press and hold it a second time to display total engine hours. To access the engine screens, press and hold the mode/reset button when the engine miles/hours screen is displayed.
Automated Transmission Display
The ICU4M can display current gear information for vehicles with an automated transmission. The last three digits at the far right on the lower line of the driver display screen are reserved for this information. If there is a request to shift, an up or down arrow is also displayed, depending on the shift direction. On vehicles with conventional manual or automatic transmissions, the gear and shift direction are not displayed. For more information about specific models of automated transmissions, see Chapter 8.
Fuel information allows you to view total fuel usage since the last reset, fuel mileage, and fuel consumed while idling or running the PTO. See Fig. 2.11. Tap the arrow keys on the 10-key keypad to advance through the screens. Press and hold the SET/RESET key to reset any of the screens.
The engine information screens allow you to view engine mileage and hours, and total fuel consumption. See Fig. 2.12. Tap the arrow keys on the 10 key keypad to advance through the screens. Press and hold the SET/RESET key to reset any of the screens.
If active fault codes are displayed on the diagnostic information screens–See Fig. 2.13, make a note of the fault code and text message, then take the vehicle to an authorized Freightliner service facility as soon as possible.
Service information allows you to view the next recurring service interval, expressed in either miles or hours. See Fig. 2.14. Service intervals can also be deactivated, so they do not display at all.
Air Intake Restriction Gauge
The air intake restriction gauge indicates the vacuum on the engine side of the air cleaner. See Fig. 2.18. On standard installations, it is mounted on the air cleaner. As an option for easier viewing, an air intake restriction indicator can be mounted on the auxiliary dash panel.
A pyrometer registers the exhaust temperature near the turbocharger. Variations in engine load can cause exhaust temperatures to vary. If the pyrometer reading shows that exhaust temperature exceeds normal, reduce fuel to the engine until the exhaust temperature is reduced. Shift to a lower gear if the engine is overloaded.
The voltmeter indicates the vehicle charging system voltage when the engine is running and the battery voltage when the engine is off. By monitoring the voltmeter, the driver can stay aware of potential battery charging problems and have them fixed before the batteries discharge enough to create starting difficulties. Vehicles are equipped with either a voltmeter gauge, or a digital voltmeter readout located on the bottom line of the dash message center.
The voltmeter will normally show approximately 13.7 to 14.1 volts when the engine is running. The voltage of a fully charged battery is 12.7 to 12.8 volts when the engine is off. Battery voltage under 12.0 volts is considered a low battery, and a completely discharged battery will produce only about 11.0 volts.
If the voltmeter shows an undercharged or overcharged condition for an extended period, have the charging system and batteries checked at an authorized Freightliner service facility.
On a vehicle equipped with a battery isolator system, the voltmeter measures the average voltage of all the batteries when the engine is running. When the engine is off, the voltmeter shows only the isolated battery voltage and does not indicate the voltage of the engine-starting batteries.
Trailer Air Supply Valve
The red octagonal-shaped knob operates the trailer air supply valve, which charges the trailer air supply system and releases the trailer spring parking brakes. See Fig. 2.21.
After the vehicle and its air hoses are connected to a trailer and the pressure in the air system is at least 65 psi (447 kPa), push the trailer air supply valve knob in (and leave it in) to charge the trailer air supply system and release the trailer spring parking brakes. Pull the trailer air supply valve out before disconnecting a trailer or when operating a vehicle without a trailer.