PLATE 1246640 - Caterpillar

Indicator LED Operation
The indicator LED's are the four LED's in the top end of the electronic hitch control. The indicator LED's can be viewed by pulling out the ash tray and looking into the hole. The top and bottom LED's are green and indicate the solenoid being requested ON by the control. The second LED from the top is the red diagnostic indicator LED which provides diagnostic information. The third LED from the top is the yellow mode indicator LED which indicates the mode of operation.
(A) Raise indicator. (B) Diagnostic indicator. (C) Mode indicator. (D) Lower indicator.Mode Indicator Operation
The mode indicator is the yellow LED which is the third LED from the top of the hitch control when viewed through the ash tray opening. The mode indicator flashes a single digit code or is either ON steady or OFF to indicate which mode the control is presently operating in. The code is a series of flashes followed by about a one second pause and the code is then repeated. See, Modes of Operation table to convert a code to a mode of operation and see, Modes of Operation for a complete description of the mode. Solenoid Request Indicator Operation
The solenoid request indicators are the top and bottom green LED's when viewed through the ash tray opening. The top LED is the raise solenoid request indicator which indicates that the hitch control is requesting the hitch to raise. The bottom LED is the lower solenoid request indicator which indicates that the hitch control is requesting the hitch to lower. If both LED's are OFF the hitch control is requesting the hitch to HOLD the present position. These solenoid request LED's can be helpful in quickly diagnosing some electronic hitch control system problems.Diagnostic Indicator Operation (Earlier Model)
The diagnostic indicator is the red LED which is the second LED from the top of the hitch when viewed through the ash tray opening. When the electronic control detects a problem, a single digit diagnostic code is flashed repeatedly with a long pause between repeating. The electronic control will shut off the mode indicator LED and stay in the diagnostic mode until the control is powered down and back up (engine key start switch OFF, then ON). The diagnostic code is lost if the control is powered down and back up if the problem is no longer present.Diagnostic Indicator Operation (Later System)
Information is shown on the diagnostic indicator by flashing the indicator ON and OFF. The information flashed represents a two digit code number. There is a series of flashes that represent the first digit followed by about a one second pause, then a series of flashes representing the second digit. Count the number of flashes to determine each digit. A pause of about 3 seconds separates each two digit flash code.The control uses the diagnostic indicator in two different modes. The modes are; normal mode & service mode.When power is applied, the control enters normal diagnostic mode. Removing the machine identification plug