R1600G Load Haul Dump Power Train Electronic Control System Switches Caterpillar

Switches (STIC Steering)

Illustration 1	g00991716
Location of the STIC steering control (1) Upshift switch (2) Downshift switch (3) Transmission direction control switch

The STIC steering control is a joystick control. The operator can select the direction of the machine with transmission direction control switch (3). The operator can select the transmission speed by pressing upshift switch (1) and downshift switch (2) .

Switch (Transmission Direction Control)

Transmission direction control switch (3) is a three-position switch that selects either forward, neutral, or reverse.

The operator selects a direction by moving transmission direction control switch (3) to one of three positions. Transmission direction control switch (3) signals the Power Train Electronic Control Module (ECM) the direction of travel that is selected. The following connections to the Power Train ECM are on connector J1: contact 30 (forward), contact 13 (neutral) and contact 14 (reverse). The selected switch position is grounded. The switch positions that are not selected are open. The valid combinations for each switch position are shown in Table 1 that follows.

ReferenceFor information on the function of the transmission direction control switch, refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Power Train Electronic Control System" for the machine that is being serviced.

ReferenceFor information on the Power Train ECM, refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Switch (Transmission Upshift)

The transmission upshift switch makes momentary contact in order to select the next higher speed. The operator selects a speed by depressing upshift switch (1) .

The transmission upshift switch has two input connections at the Power Train Electronic Control Module (ECM). The two input connections at the Power Train ECM are upshift N/C at contact J1-19 and upshift N/O at contact J1-23. When the operator activates the upshift switch, the upshift N/C circuit is open and the upshift N/O circuit is closed to ground. When the switch is not activated, the upshift N/C circuit is closed to ground and the upshift N/O circuit is open. The valid combinations for each switch position are shown in Table 2 that follows.

ReferenceFor information on the function of the transmission upshift switch, refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Power Train Electronic Control System" for the machine that is being serviced.

ReferenceFor information on the Power Train ECM, refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Switch (Transmission Downshift)

The transmission downshift switch makes momentary contact in order to select the next lower speed. The operator selects a speed by depressing downshift switch (2) .

The transmission downshift switch has two input connections to the Power Train Electronic Control Module (ECM). The two input connections at the Power Train ECM are downshift N/C at contact J1-25 and downshift N/O at contact J1-26. When the operator activates the downshift switch, the downshift N/C circuit is open and the downshift N/O circuit is closed to ground. When the switch is not activated, the downshift N/C circuit is closed to ground and the downshift N/O circuit is open. The valid combinations for each switch position are shown in Table 3 that follows.

ReferenceFor information on the function of the transmission downshift switch, refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Power Train Electronic Control System" for the machine that is being serviced.

ReferenceFor information on the Power Train ECM, refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Rotary Switch (Autoshift Control)

Illustration 2	g01027335

The autoshift control switch sends an input to the Power Train Electronic Control Module (ECM). The autoshift control switch has a MANUAL position and three AUTO positions. The autoshift control switch is used to select the top speed of the transmission when the switch is in the AUTO position. The autoshift control switch has four inputs. The valid combinations for each switch position are shown in Table 4 that follows. If an invalid combination is detected by the Power Train ECM, a circuit failure is present.

ReferenceFor information on the function of the autoshift control, refer to Systems Operation Troubleshooting, Testing and Adjusting, "Power Train Electronic Control System" for the machine that is being serviced.

ReferenceFor information on the function of the Power Train ECM, refer to Systems Operation Troubleshooting, Testing and Adjusting, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Limit Switch (STIC Control Lock)

Illustration 3	g01027327
STIC control lock (1) Steering and transmission lock lever (2) Limit switch (STIC control lock)

Illustration 4	g00573835
Limit switch (STIC control lock)

Note: The limit switch is part of the STIC control lock.

The limit switch (STIC control lock) is used to lock the transmission in the neutral position. The limit switch (STIC control lock) is activated by steering and transmission lock lever (1). The steering and transmission lock lever is located on the operator station door. The transmission will be in neutral if the steering and transmission lock lever is in the LOCKED position.

After steering and transmission lock lever (1) is placed in the UNLOCKED position the transmission is in neutral. The transmission will remain in neutral until the operator moves the transmission direction control switch to the NEUTRAL position, then into the FORWARD position or the REVERSE position.

The valid combinations for each switch position are shown in Table 5 that follows.

ReferenceFor information on the Power Train ECM, refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Transmission Neutralizer Switch

Illustration 5	g00287699
Transmission neutralizer switch

The transmission neutralizer switch is an input of the Power Train Electronic Control Module (ECM).

The transmission neutralizer switch is a two-position limit switch. The transmission neutralizer switch informs the Power Train ECM when the service brake and transmission neutralizer pedal is depressed. When the transmission neutralizer switch is activated the switch is open. When the transmission neutralizer switch is deactivated, the switch closes contact J2-4 of the Power Train ECM to ground. When the N/O contact is NOT grounded, the Power Train ECM initiates the neutralizer function. The COM terminal is connected to frame ground. The N/C terminal of the switch is not used.

Pressure Switch (Parking Brake Oil) (Electronic Transmission Control)

Illustration 6	g00287701

The parking brake oil pressure switch is an input of the Power Train Electronic Control Module (ECM). This switch signals the Power Train ECM when the parking brake is engaged.

The parking brake oil pressure switch is a double-pole, single-throw pressure switch. When the operator engages the parking brake, the normally open (N/O) pole opens and the normally closed (N/C) pole closes to ground. This signals the Power Train ECM that the parking brake is engaged. When the parking brake is disengaged, the N/O pole is closed and the N/C pole is open. This signals the Power Train ECM that the parking brake pressure switch circuit is operating correctly. The N/C pole connects to connector contact J1-27 of the Power Train ECM. The N/O pole connects to connector contact J1-36 of the Power Train ECM. The common terminal of the switch connects to ground.

Note: The normally closed (N/C) circuit and normally open (N/O) circuit of the parking brake pressure switch are used for diagnostic purposes. A circuit failure is present if the two circuits are open at the same time or if the two circuits are grounded at the same time. This fault is then shown on the display of the AVSpare Monitoring System.

ReferenceFor information on the diagnostic operations, refer to Systems Operation Troubleshooting, Testing and Adjusting, "Power Train Electronic Control System" for the machine that is being serviced.

ReferenceFor information on the parking brake function, refer to Systems Operation Troubleshooting, Testing and Adjusting, "Power Train Electronic Control System" for the machine that is being serviced.

ReferenceFor information on the Power Train ECM, refer to Systems Operation Troubleshooting, Testing and Adjusting, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Start Switch (Key)

Illustration 7	g00497430
Key start switch

The key start switch is an input of the Power Train Electronic Control Module (ECM). The switch connects to connector contact J1-40. The switch sends a signal to the Power Train ECM that the operator wants to start the engine. The Power Train ECM then initiates the neutral start function. The signal is open during normal operation. The switch closes to the +battery when the switch is in the START position.

The switch has a connector with four contacts. Contact 1 connects to the main power relay. Contact 2 is not used. Contact 3 connects to the key start switch contact J1-40 on the Power Train ECM. Contact 4 connects to battery voltage.

Note: After the switch is initially turned to the START position, the switch will not return to the START position from the ON position. The switch must be turned to the OFF position. The switch can then be turned to the START position.

The Power Train ECM does not record diagnostic codes that are related with the key start switch.

ReferenceFor information on the neutral start function, refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Power Train Electronic Control System" for the machine that is being serviced.

ReferenceFor information on the Power Train ECM, refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Rocker Switch (Ride Control)

Illustration 8	g00288392
Ride Control Switch

The ride control switch is an input of the Power Train Electronic Control Module (ECM). The ride control switch informs the Power Train ECM of the ride control mode that is selected. The ride control switch has three positions: SERVICE position, OFF position and AUTO position.

The ride control switch has two input connections to the Power Train ECM at connector J1: input 1 at contact 21 and input 2 at contact 22. When the switch is moved to the SERVICE position, input 1 is open to ground and input 2 is closed. When the switch is moved to the AUTO position, input 1 is closed and input 2 is open to ground. When the switch is moved to the OFF position, input 1 and input 2 are closed to ground. The valid combinations for each switch position are shown in Table 7 that follows.

ReferenceFor more information on the ride control function, refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Power Train Electronic Control System" for the machine that is being serviced.

ReferenceFor information on the Power Train ECM, refer to Systems Operation, Troubleshooting, Testing and Adjusting, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Lockup Clutch Switch (Torque Converter Lockup)

Illustration 9	g00574911
Lockup Clutch Switch

The lockup clutch switch is an input of the Power Train Electronic Control Module (ECM). The lockup clutch switch signals the Power Train ECM to enable the lockup clutch function. The Power Train ECM does not diagnose faults on this switch.

The lockup clutch switch is a two-position rocker switch. When the switch is moved to the ON position, the switch closes connector contact J2-11 to ground. When the switch is moved to the OFF position, the switch is open to ground. Terminals 1, 4, 5 and 6 are not used. Terminal 2 connects to connector contact J2-11 of the Power Train ECM. Terminal 3 connects to the ground.

The valid combinations for each switch position are shown in Table 8 that follows.