BOLT-WHEEL 0772802 - Caterpillar

Light-Emitting Diode (LED)
Controller Assembly
(1) LED display. (2) Controller. (3) Test switch 2 (SW2). (4) Test switch 1 (SW1).
Controller LED Display
(5) ON during engine operation. (6) ON when AEC is turned ON. (7) OFF. (8) Unpredictable. (9) ON 0.5 second for every second. (10) ON when the error persists and OFF when corrected. (11) ON 0.5 second for every 2 seconds.To determine the actual problem location, the operator has to look at display (1) of controller (2). The display consists of nine light emitting diodes (LEDs) that are ON or OFF.The LED display pattern 1 shows that the electronic control functions properly. The LED patterns 2 to 9 indicate any error in the indicated system. The LED display patterns 10 and 11 will appear if the governor control lever is moved considerably for speed increase or decrease when the machine control lever is being operated. These two patterns show no error.The LED error display will disappear when the error is eliminated. However, if any error occurs in the following systems (with the error code hold function), the LED error displays, L1, L2, L3 and L4 will continue until SW1 (4) or SW2 (3) is pressed for three seconds or more after the removal of the error.1. Controller memory2. Proportional reducing valve3. AEC relay systemLED displays allow fast and easy troubleshooting of the electronic power control system. These functions are intended to mainly check the electrical circuits that provide input and output signals to the controller. They are limited to problems such as open and/or short circuits. They cannot detect the location of open or short circuits.Controller Problem (LED Display 2)
These LED's, when ON, indicate that the controller is out of order and provides irregular outputs to the proportional reducing valve and AEC motor. As a result, a correct amount of the power shift pressure will not be maintained. A decreased power shift pressure could cause an engine stall or an increased power shift pressure could cause not enough power and speed. The AEC may not be operated or reset.Controller Memory Problem (LED Display 3)
These LED's, when ON, indicate that the calibration memory integrated circuit (IC) of the proportional reducing valve is defective. The PRV not correctly calibrated could cause not enough engine speed and/or power.Proportional Reducing Valve System Problem (LED Display 4)
If an open or short circuit occurs, there is no signal current sent to the proportional reducing valve which in turn provides no power shift pressure. As a result, the pump flow becomes maximum and the engine decreases its speed.AEC Relay System Problem (LED Display 5)
If there is an open or short circuit between the controller and AEC relay, the AEC motor, even if in decelerated position, will then rotate 180° and stop as it reaches the accelerated position. If there is an open or short circuit between the AEC relay and AEC motor, the AEC motor will stay in its present position.Power Mode Switch System Problem (LED Display 6)
When the above LED's are ON, the power mode