16. TROUBLESHOOTING CHASSIS (continued) (16.4.3) IF ACCELERATOR PEDAL HAS FAILED In addition to the potentiometer detecting the pedal depression depth, the switch is installed on the accelerator pedal assembly in order to detect whether the accelerator pedal is depressed or not. If the pedal depression depth is not detected correctly due to a failure of the accelerator pedal or incorrect electric wiring, the engine controller or PMC (if equipped) controls the engine speed responding to the signal from this check switch. The engine runs at 1400 rpm when the accelerator pedal is depressed, while the engine runs at low idling when the pedal is released.
The engine speed varies depending on the load. After moving the machine to a safe place by operating the accelerator pedal, contact your Komatsu distributor for repairs. There are two methods when operating the accelerator pedal: either release the pedal and set to the OFF (low idling) position, or depress the pedal fully (1400 rpm). If the accelerator pedal is held at an intermediate position, the system may not be able to judge if the accelerator pedal is being operated or not.
REMARK If the engine controller or PMC (if equipped) can not be received the signal of the accelerator pedal depth, the central warning lamp flashes and simultaneously the alarm buzzer sounds and action code “02” appears. 2-115 Problem Main causes Remedy Work equipment speed is slow ‡ Defective gear pump ‡ Insufficient oil (‡ Replace gear pump) ‡ Add oil to specified level. See CHECK BEFORE STARTING.
Suspension is hard ‡ Entry of soil or sand due to break- age of dust seal, gas leakage due to breakage of U-packing ‡ Gas leaking from valve core (‡ Replace U-packing) (‡ Replace valve core) Rear wheel on one side tends to slip ‡ Air in rear brake circuit (between slack adjuster and rear brake) ‡ Excessive difference in wear between left and right tires ‡ Excessive difference in division of load between left and right wheels (unbalanced load) ‡ Excessive deformation of disc ‡ Bleed air from rear brakes (left, right). See WHEN REQUIRED. (‡ Replace tires) ‡ Make load uniform (‡ Disassemble and adjust brake)