SEAL 3645742 - Caterpillar

Illustration 1 g00350142
(A10) Engine speed (A11) ARC On (A12) Engine oil pressure (MUI engines) (A13) Accelerator pedal (MUI engines) (A16) Auto retarder pressure (A21) Retarder pressure (A26) ARC OffMode 2 is used to determine the status of the inputs for the Automatic Retarder Control (ARC). The ARC does not detect all faults. This mode is useful for tracing circuits and for determining the status of the inputs. The Electrical System Schematic is also necessary in order to properly use Mode 2.The readout consists of numerous segments. Each input and the corresponding connector contact is assigned to a specific segment of the readout. See Illustration 1. If a segment is on, the corresponding input is grounded. If a segment is off, the corresponding input is open. All of the segments of the readout are not used.Note: If segment (A10) is on, the corresponding input is valid. This means that the engine is running. If segment (A10) is off, the corresponding input is not valid. This means that the engine is stopped.Note: The indicators also function in the same manner as the Normal Mode (Mode 0). See Systems Operation, "Normal Mode". Some of the segments in Mode 2 will duplicate the information that is shown on the indicators.The display enters Mode 2 when "-2-" is shown on the readout and the set switch and the clear switch are released. The display exits Mode 2 when the set switch and the clear switch are depressed simultaneously or when the engine start switch is turned to the OFF position.For more information about changing modes, see Testing and Adjusting, "Using Service Display Mode to Determine Diagnostic Codes".
Illustration 2 g00350143
Example (1) Power indicator (2) Control indicator (3) Auto retarder indicator (4) Retarder indicator (5) Parking brake indicator (6) Accelerator pedal indicator (7) Engine speed indicator (8) Fault present indicator (10) Service mode indicator (later models) (A10) Engine speed (A11) ARC On (A12) Engine oil pressure (MUI engines) (A13) Accelerator pedal (MUI engines) (A16) Auto retarder pressure (A21) Retarder pressure (A26) ARC OffThis example describes the information on the display. The following conditions exist for this example:
The engine start switch is in the ON position.
The engine is running at low idle.
The on/off switch for the ARC is in the ON position.
The transmission control lever is in the NEUTRAL position.
The parking brake is activated.
The display is in Mode 2.With the above conditions, the display is showing the following information: (A10) Segment and ContactON - The ARC reads the engine speed input as a valid input. This means that the engine is running.OFF - The ARC reads the engine speed input as not being a valid input. This means that the engine is not running. (A11) Segment and ContactON - The ARC reads the inputs as being grounded.OFF - The ARC reads the input as being open. (A12 (MUI only)) Segment and ContactON - The ARC reads the engine oil pressure input as being grounded.OFF - The ARC reads the engine oil pressure input as being