SHOE 2G7504 - Caterpillar

Key Switch
Illustration 1 g03329390The key switch is a three position switch with two inputs into the chassis ECM. When the key switch is moved to the ON position, a system voltage input is provided to the chassis ECM. The presence of this voltage input will cause the ECM to transition from the "sleep mode" to the operational mode. When this mode change occurs, the ECM will initialize and then become operational.When the key switch is moved to the OFF, the system voltage is no longer present at the ECM contact. The absence of the system voltage signals the ECM to transition from the operational mode to the sleep mode. The ECM will perform some inter power down procedures and then enter the sleep mode.The transition period from the sleep mode to the operational mode happens in a short time. When the key switch is moved to the start position, a system voltage input will be provided to the chassis ECM start contact. When the ECM detects this voltage and the machine system start status is correct, the ECM will initiate the engine cranking sequence.Access Lighting Switch
Illustration 2 g03672328The access lighting switch is a single pole switch. The switch has a contact that connects to the power train ECM. When the switch is not engaged, the ECM contact is pulled to a low voltage state. When the switch is engaged, the ECM contact is connected to battery voltage and is pulled to a high-voltage state. Based on the voltage state of the two ECM contacts, the ECM determines if the switch is engaged. The switch controls the access lighting.Forward ROPS and Cylinder Lights Switch
Illustration 3 g03672338The forward ROPS and cylinder lights switch is a two pole switch. The switch has a contact that connects to the power train ECM, and a contact that connects to the forward ROPS and cylinder lights relay.Operator Presence Switch
The operator presence sensor is located in the seat cushion for the operator seat. The sensor is an analog voltage sensor that varies with pressure.Forward ROPS Light Relay
The forward ROPS light relay allows power to travel to the lights mounted on the ROPS. The ECM controls the operation of the relay.Seatbelt Switch
Illustration 4 g03350093The seatbelt switch is a double pole switch. The switch has a normally connected and a normally open contact. When the switch is not engaged the normally connected contact is connected to the return, and the normally open contact floats to a high-voltage state. When the switch is engaged, the normally open contact is connected to the return and the normally connected contact floats to a high-voltage state. Based on the voltage state of the two ECM contacts, the ECM determines if the switch is engaged. The switch alerts the power train ECM of the state of the seatbelt.
Illustration 5 g06071766There is a beacon sinking driver available on the Powertrain ECM connector J2 pin 21 that can be wired to supply a signal to customer wired relay which can turn on the beacon when the unbuckled seatbelt warning