950G Series II Wheel Loader, 962G Series II Wheel Loader and IT62G Series II Integrated Toolcarrier Power Train Caterpillar

• When the switch is open, no signal is provided to the corresponding input of the power train ECM.

• When a switch is closed, a ground signal or a +battery signal is provided to the corresponding input of the power train ECM.

Momentary Contact Switch with IBS

Illustration 1	g00918940
Transmission Neutralizer Enable/Disable

The transmission neutralizer enable/disable switch is an input to the power train electronic control module (ECM). The transmission neutralizer enable/disable switch signals the power train ECM to enable/disable the neutralizing function of the left brake pedal.

Upon powerup, the power train ECM defaults to the transmission neutralizer function enabled. The transmission neutralizer enable/disable switch is a momentary contact switch. When the transmission neutralizer enable/disable switch is activated, contact J1-34 will be connected to the +Battery connection and the power train ECM will disable the neutralizer function until the switch is pushed again or until the engine is shut off. The switch has five terminals. The neutralizer disable indicator in the dash will remain on while the neutralizer function is disabled. Terminal A and terminal B turn on the internal switch indicator. Terminal 3 connects to connector contact J2-4 of the power train ECM. Terminal 2 connects to the ground.

Reference: For more information on the functioning of the transmission neutralizer, refer to the Systems Operation, "Power Train Electronic Control System" for the machine that is being serviced.

Reference: For more information on the transmission neutralizer switches, refer to the Service Manual module Operation and Maintenance Manual for the machine that is being serviced.

Reference: For more information on the function of the power train ECM, refer to theSystems Operation, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Rotary Switch (Variable Shift Control)

Illustration 2	g00779624
Variable Shift Control Switch

The variable shift control switch is an input of the power train ECM. The switch allows the selection of a range of points to shift the transmission for each speed. The switch has three inputs to the power train ECM. The combination of inputs for each switch position are shown in Table 1.

Reference: For more information on the variable shift control, refer to the Service Manual module Operation and Maintenance Manual, "Variable Shift Control" for the machine that is being serviced.

Pressure Switch (Parking Brake Oil)

Illustration 3	g00287701
Parking Brake Pressure Switch

The parking brake pressure switch is an input of the power train electronic control module (ECM). This switch informs the power train ECM when the parking brake is engaged.

The parking brake 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 tells 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 tells the power train ECM that the parking brake pressure switch circuit is operating correctly. No action is required. 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 power train ECM.

Reference: For more information on the diagnostic operations, refer to Systems Operation, "Power Train Electronic Control System" for the machine that is being serviced.

Reference: For more information on the parking brake function, refer to Systems Operation, "Power Train Electronic Control System" for the machine that is being serviced.

Reference: For more information on the function of the power train ECM, refer to Systems Operation, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Switches (Conventional Steering)

Switch (Transmission Direction and Speed Control Lever)

Illustration 4	g00824420
(1) Transmission direction and speed control lever.

The switches in the transmission direction and speed control lever are inputs to the power train electronic control module (ECM). The switches send information to the power train ECM about the speed that has been selected and the direction that has been selected with the transmission direction and speed control lever. The switches close the direction/speed inputs to ground on the power train ECM.

Reference: For more information on the function of the transmission direction and speed control lever, refer to Systems Operation, "Power Train Electronic Control System" for the machine that is being serviced.

Reference: For more information on the function of the power train ECM, refer to Systems Operation, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Switch (Transmission Downshift)

Illustration 5	g00824409
Downshift Switch

The downshift switch signals the power train electronic control module (ECM) to downshift the transmission by one speed. To downshift, the operator depresses the downshift switch. The downshift switch has one input connections to the power train ECM on connector J2: downshift N/O at contact 5. When the operator presses the downshift switch, the downshift N/O circuit is closed to ground. When the downshift switch is not activated, the downshift N/O circuit is open or floating.

Reference: For more information on the function of the transmission downshift switch, refer to Systems Operation, "Power Train Electronic Control System" for the machine that is being serviced.

Reference: For more information on the function of the power train ECM, refer to Systems Operation, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Rotary Switch (Autoshift Control)

Illustration 6	g00328469
Autoshift control switch for a machine that is equipped with Conventional Steering

The autoshift control switch tells the power train electronic control module (ECM) of the desired shift mode, AUTO mode or MANUAL mode. The switch has three input connections to the power train ECM on connector J1: MANUAL mode at contact 29, AUTO mode at contact 31 and AUTO mode at contact 35. Two switch contacts are used for diagnosing a failure of the switch. A circuit failure is present if both of the switch contacts are open at the same time or if the two switch contacts are grounded at the same time. The valid combinations for each switch position are shown in Table 2 that follows.

Reference: For more information on the function of the autoshift control, refer to Systems Operation, "Power Train Electronic Control System" for the machine that is being serviced.

Reference: For more information on the function of the power train ECM, refer to Systems Operation, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Switches (Command Control Steering)

Switch (Transmission Direction Control)

Illustration 7	g00824885
(1) Transmission direction control switch. (2) Transmission speed selector switch.

The transmission direction control switch (1) and the transmission speed selector switch (2) are located on the steering wheel. The transmission direction control switch is a three-position switch. The transmission direction control switch allows the operator to select the transmission direction: forward, neutral and reverse.

The operator selects a direction by moving the transmission direction control switch to one of three positions. The transmission direction control switch tells 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 3 that follows.

Reference: For more information on the function of the transmission direction control switch, refer to Systems Operation, "Power Train Electronic Control System" for the machine that is being serviced.

Reference: For more information on the function of the power train ECM, refer to Systems Operation, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Switch (Transmission Speed Selector)

Illustration 8	g00824898
(2) Transmission speed selector switch.

The transmission speed selector switch (2) is located on the steering wheel. The transmission speed selector switch is a momentary rocker switch that allows the operator to select the speed range of the transmission when the transmission is in the MANUAL mode.

Note: When the transmission is the AUTO mode, the transmission speed selector switch can be used to downshift from second speed to first speed for the purpose of loading a bucket. The transmission will remain in the downshifted gear for three seconds after the switch is released. Then, automatic shifting will resume.

Upshift

Press the top of the transmission speed selector switch in order to increase the speed of the transmission. The power train ECM will upshift the transmission to the next higher gear.

The transmission speed selector switch has two input connections at the power train electronic control module (ECM). The two input connections at the power train ECM on connector J1 follow: upshift N/C at contact 19 and upshift N/O at contact 23. When the operator presses the top of the transmission speed selector 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 4 that follows.

Note: The normally closed (N/C) circuit and normally open (N/O) circuit of the transmission speed selector switch is used for diagnostic purposes. If the normally closed (N/C) circuit and the normally open (N/O) circuit are open at the same time, the power train ECM records a fault. If the normally closed (N/C) circuit and the normally open (N/O) circuit are grounded at the same time, the power train ECM records a fault.

Reference: For more information on the function of the transmission speed selector switch, refer to Systems Operation, "Power Train Electronic Control System" for the machine that is being serviced.

Reference: For more information on the function of the power train ECM, refer to Systems Operation, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Downshift

Press the bottom of the transmission speed selector switch in order to decrease the speed of the transmission. The power train ECM will downshift the transmission to the next lower gear.

Transmission speed selector switch (2) has two input connections to the power train electronic control module (ECM) on connector J1: downshift N/C at contact 25 and downshift N/O at contact 26. When the operator presses the bottom of the transmission speed selector 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 5 that follows.

Note: The normally closed (N/C) circuit and normally open (N/O) circuit of the transmission speed selector switch is used for diagnostic purposes. If the normally closed (N/C) circuit and the normally open (N/O) circuit are open at the same time, the power train ECM records a fault. If the normally closed (N/C) circuit and the normally open (N/O) circuit are grounded at the same time, the power train ECM records a fault.

Reference: For more information on the diagnostic operations, refer to Systems Operation, "Power Train Electronic Control System" for the machine that is being serviced.

Rotary Switch (Autoshift Control)

Illustration 9	g00779622
Autoshift control switch

The autoshift control switch sends an input to the power train ECM. The switch is used to select the top speed of the transmission when the transmission is in AUTO mode. The autoshift control switch has five inputs. One position is for the MANUAL mode. The other four positions are for AUTO mode. The valid combinations for each switch position are shown in Table 6 that follows.

Reference: For more information on the autoshift control, refer to the Systems Operation, "Autoshift Control" for the machine that is being serviced.

Rocker Switch (Ride Control)

Illustration 10	g00288392
Ride Control Switch

The ride control switch informs the power train electronic control module (ECM) of the ride control mode that is selected. There are three ride control modes: AUTO, ON and OFF.

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 operator selects the AUTO position, input 1 is closed to ground and input 2 is open. When the ON position is selected, input 1 is open and input 2 is closed to ground. When the OFF position is selected, input 1 and input 2 are closed to ground. The valid combinations for each switch position are shown in Table 7 that follows.

Reference: For more information on the ride control function, refer to Systems Operation, "Power Train Electronic Control System" for the machine that is being serviced.

Reference: For more information on the function of the power train ECM, refer to Systems Operation, "Electronic Control Module (Power Train)" for the machine that is being serviced.

Start Switch (Key)

Illustration 11	g00291705
Key Start Switch

The key start switch is an input of the power train electronic control module (ECM). The key start switch informs the power train ECM of an attempt to start the engine. The power train ECM then initiates the neutral start function.

During normal machine operation, the start terminal of the key start switch is open. When the key start switch is turned to the START position, the start terminal closes to the +battery and the +battery voltage is present at connector contact J1-40 of the power train ECM. When all starting conditions are satisfied, the power train ECM sends a +battery signal to the connector contact J1-8 for the start relay and engine cranking begins.

Note: After the key start 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 first. Then, the switch can be turned to the START position.

Reference: For more information on the neutral start function, refer to Systems Operation, "Power Train Electronic Control System" for the machine that is being serviced.

Reference: For more information on the function of the power train ECM, refer to Systems Operation, "Electronic Control Module (Power Train)" for the machine that is being serviced.