OM3018 08/07 Operation - Section 3 Operating Instructions Page 3-21 Fault Check Switch (11, Figure 3-2) This Fault Check switch, when moved to the "ON" (down) position, may be used to activate the engine electronic control system diagnostic codes. When the system detects a "fault" and one of the indicator lamps (7, 8, 9) illuminates as previously described, this switch will permit determination of the kind of "fault(s)* detected. Each digit is indicated with up to nine light flashes for each digit. There is a short pause between each digit of the fault code. c.
After all three digits are flashed, the yellow lamp will flash once, and then the red lamp will repeat the same fault code sequence as before. Fault Scroll Switch (12, Figure 3-2) This Fault Scroll switch may be used to scroll through the recorded faults held in memory. It will display only active fault codes. 4. The system will continue to flash the same fault code until the Fault Scroll Switch (12) is acti- vated again. To display the next active fault code, move the switch lever to the "up" posi- tion momentarily and release (switch is spring-loaded to the center "OFF" position). Activating the switch again will advance to the next fault code, etc.
Once all active fault codes have been displayed, the fault code display sequence will be repeated, starting from the first fault code. EXITING THE DIAGNOSTICS MODE Starting the engine, or turning the key- switch to the OFF position, will EXIT the diagnostics fault flash mode. Moving the switch lever to the "down" position momentarily and releasing, permits the system to scroll (as described above) backwards through the fault "list". Determining "Fault" Codes If active fault codes have been determined as described previously, refer to the appropriate Komatsu engine manual. 1. To determine an active "fault", turn the key- switch to the "OFF" position and wait until the engine completely stops.
2. Turn keyswitch to "ON" position (engine NOT running) and hold the Fault Check switch (11) in the "ON" position. Differential Lock Pedal (Optional) If truck is equipped, this pedal (11, Figure 3-1) is used to actu- ate the differential lock control. 3. If there is an active fault: When the pedal is depressed, the differential lock is actuated, and when it is released, the dif- ferential lock is canceled. Depress differential lock pedal 5 - 10 m (16 - 33 ft.) before entering the area where the tires may start to slip. a. The amber/yellow Engine Maintenance light (8) will flash once. NOTE:
Do not apply the differential if the wheels are already slipping or truck speed is higher than 12.4 MPH (20 km/h) 4th gear. b. There will be a 1-2 second pause, and then the red Engine Shutdown light (7) will flash out the three digit diagnostic code. Do not use the differential lock while turning a corner. Refer to Section G of this manual for further details.