VALVE-RELIEF 1541942 - Caterpillar

Main Pump Pressure Switch
The main pump pressure switch provides one switch-to-ground input to the machine ECM. The ECM will use the input from the pressure switch to determine if the machine is performing work or if the output of the main hydraulic pump is not being used.The ECM will use the status of the main pump pressure switch and the status of the swing pilot pressure switch for control of several different machine functions including: the AESC operation, the operation of the auto lube system, the machine working status and the machine power demand status.The ECM will determine that the machine is not performing work when the main pump pressure switch contacts are open which indicates a low-pressure output from the pump. when the pump pressure increases and the switch contacts are closed, the ECM will determine that a load is present on the pump and the machine is working.The actuation pressure setting of the main pump pressure switch is approximately 490 kPa (70 psi). The de-actuation pressure setting of the switch is approximately 290 kPa (42 psi).Implement ECM
When the implement ECM is installed on the machine, the ECM will be used as a secondary control module to the primary machine ECM. The implement ECM is used to control the outputs that are used for the attachments that are listed above. The implement ECM controls the outputs based on the command information that is received from the machine ECM. The implement ECM receives no input data from any external devices other than a key switch input.The implement ECM will activate outputs in order to energize or de-energize solenoids that will control the installed machine functions.The machine will be equipped with the implement ECM in order to control any of the following attachments when installed on the machine:
Auxiliary hydraulics (MCV)
Joystick steering
Ride control
Smart boom
Illustration 5 g03704942
Implement ECM
Pin Locations for Implement ECM
Illustration 6 g03704949
Implement ECM connector (70-pin)
Table 2
Implement ECM - Contact Connections
Pin Location Function Description
34 Joystick steering left solenoid Output
35 Joystick steering left solenoid return Ground
40 Joystick steering right solenoid Output
41 Joystick steering right solenoid return Ground
50 Auxiliary #2 port "B" solenoid Output
51 Auxiliary #2 port "B" solenoid return Ground
55 8 vdc sensor return of pin 22, 23, 28 (GND) Ground
58 Auxiliary #2 port "A" solenoid Output
59 Auxiliary #2 port "A" solenoid return Ground
64 CAN A + (J1939 data link) Input/output
65 CAN A - (J1939 data link) Input/output
66 CAN B + (local) Input/output
67 CAN B - (local) Input/output
68 8 VDC sensor supply Power Overload Warning Enable Control
Overload Warning Enable Control (9) - The overload warning device should be engaged when the machine is used to lift an object. To turn ON the overload warning function, press the soft switch panel button. The Machine ECM will illuminate the LED indicator. The overload warning device will sound an alarm when the machine is at the maximum lift capacity. Reduce the load if the alarm is activated. Implement Lockout Control
Implement lockout (10) - push this soft switch panel button in order to deactivate any implement or