OM3012.3 Operation - Section 3 Instrument Panel and Controls Page 3-19 FIGURE 3-6. INSTRUMENT PANEL (RIGHT SIDE) (19) Shift Indicator Gauge (20) Engine Overspeed Warning Light If the warning light (20) illuminates and the warning buzzer (47) sounds, the operator MUST take some action to reduce the engine speed BELOW 2350 RPM. i.e. Remove foot from accelerator, and apply the re- tarder (and/or service brakes, if necessary) to slow the vehicle down. The shift indicator gauge (19, Figure 3-6), will aid the operator in range pre-selection. Truck Operation with Engine Overspeed Control:
This gauge will provide the operator with a visual indi- cation of the gear range attained, versus the gear range selected. For example, if the operator has selected "D" (auto-shift, ranges 1 -- 6), the gauge will indicate the specific range that the transmission has actually achieved . This Operator should periodically review the "Operat- ing Instructions" in this Operation and Maintenance Manual, especially the areas regarding Retarding Op- eration and pre-selection of the proper transmission gear range for downhill hauling. If the engine speed exceeds 2350 RPM, the trans- mission control PROM will cause the warning light (20) to illuminate and the warning buzzer (47) to sound.
The left side of the display indicates which gear range has been selected on the Range Selector. The right side of the display indicates in which gear the transmission is actually operating. At 2400 RPM, the transmission will upshift. The transmission will continue to upshift (to 6th range, if required) until the engine speed is reduced below 2350 RPM. The center of the display marked "ON" is illuminated when Lockup is applied. For example, if the range selector is positioned in the "4" slot, the transmission control will allow upshifts all the way through 6th range, unless the engine speed is reduced below 2350 RPM.