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Input Function: Pump Mode (4th Lockup) on Allison Transmission 4700RDS

Pump Mode (4th Lockup) - 4700RDS

Figure 1.1 - Shift Selector (4th Lockup/ 5-5)

This function is available on more than one wire. Be sure to select the schematic with the wire number specified in the TCM.
Figure 1.2 - Current Calibration/CMC (Reprogram)
You can use the Allison DOC software to determine the active I/O Package Number (TCM Information - Calibration Group/Active Package) and the wire number assigned to the function in the active package (Data Monitor - Input/Output Functions).
Figure 1.3 - Calibration Group/Active Package
Figure 1.4 - Input/Output Functions


#Guidelines for Selecting Input Pump Mode (4th Lockup)
Two variations of this function are offered.
  • Operator and Pump Activated: TCM commands shift from Road Mode to Pump Mode based on position of Pump Mode switch, plus detection of positive engagement of the split-shaft PTO in the pump position.
  • Operator Only Activation: TCM commands shift from Road Mode to Pump Mode based on position of Pump Mode switch.

The table below lists the wiring schematics for input Pump Mode (4th Lockup):


A). Operator and Pump Activated (Enabled by: Input Wires #122 and #123, Output Wire #145)
→Applicable Transmissions: 3000/4000 Product Family
→Descriptions: This function is enabled when wire #123 is switched to send power to the TCM, and a switch is closed to complete the circuit between input wire #122 and wire #103, Signal Return. When this function is enabled and a specific set of conditions exist, the TCM will command the Transmission to operate in 4th-gear-lockup (Shift Selector: 5-5). The switch on wire #123 reflects the selection of the Auxiliary (Pump) Mode by the Operator, and is typically interlock with the Parking Brake to assure the brake has been actuated before operation of the Auxiliary equipment can be requested. The separate switch on wire #122 denotes the mechanical verification of the split-shaft PTO shift. A second set of contacts on this same switch is used to control illumination of the "OK To Pump/PTO" lamp. Required operating conditions for enabling the function are:
▪Vehicle Parking Brake is activated
▪Pump Mode is selected
▪Auxiliary equipment is fully engaged
▪Drive (D) is selected on the Shift Selector

B). Operator Only Activation (Enabled by: Input Wires #122 and #123, Output Wire #145)
→Applicable Transmissions: 3000/4000 Product Family
→Descriptions: This function is enabled when wire #123 is switched to send power to the TCM, and a switch is closed to complete the circuit between input wire #122 and wire #103, Signal Return. When this function is enabled and a specific set of conditions exist, the TCM will command the Transmission to operate in 4th-gear-lockup (Shift Selector: 5-5). Both input wires are switched by the selection of the Auxiliary (Pump) Mode by the Operator, and are typically also interlocked with the Parking Brake to assure the brake has been engaged before Pump Mode can be requested. A separate switch which detects physical completion of the split-shaft PTO shift (PTO is physically fully engaged) is used to control illumination of the "OK To Pump/PTO" lamp. Required operating conditions for enabling the function are:
▪Vehicle Parking Brake is activated
▪Pump Mode is selected
▪Drive (D) is selected on the Shift Selector

→When either of the input signals is disabled, normal automatic shifting resumes.
→Uses: This function is used in commercial vehicles which are equipped with a Pump, fan, or other Auxiliary equipment which is driven by a split-shaft PTO. Vehicle configurations of this type typically require Transmission operation in 4th Lockup (Direct Drive) to power the Auxiliary equipment. Activation of this feature initiates both the engagement of the split-shaft PTO and shifting of the Transmission to 4th range lockup.

#To Engage:
→Select Neutral (N) using the Shift Selector - Transmission shifts to Neutral.
→Apply Parking Brake.
→Select Pump with Dash Switch (PTO Switch ON) - Turns on "Pump Mode Requested" light. Turns on input signal to TCM (wire #123) which requests "Pump" Mode. When split-shaft shifts, wire #122 is activated and the "Pump Engaged/PTO" light is turned on.
→Select Drive (D) on the Shift Selector.
Figure 1.5 - 4th Range Lockup (5-5)
▪Gear Commanded/Selected = 4th
▪Shift Selector Range/Selected = 5
▪Input #123 - Lock Up Pump Mode (FTPM) = ON 
▪Input #122 - Pump Pack Enable = ON
▪Output #145 - Range Indicator = ON

#To Disengage:
→Select Neutral (N) using the Shift Selector - Transmission shifts to Neutral if output shaft speed is less than 1000 RPM.
→Select Road Mode - PTO disengages (PTO Switch OFF). If output shaft rotation continuous, press the "Momentary Trans. Brake" switch before selecting Road Mode. This will cause the Transmission output shaft to stop if the Transmission is in Neutral and output shaft speed is less than 175 RPM.
Figure 1.6 - Neutral (N)
▪Gear Commanded/Selected = Neutral
▪Shift Selector Range/Selected = N
▪Input #123 - Lock Up Pump Mode (FTPM) = OFF
▪Input #122 - Pump Pack Enable = OFF
▪Output #145 - Range Indicator = OFF


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