Service Brake Pressure Switch
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| Illustration 1 | g00381992 |
Service Brake Pressure Switch | |
The service brake pressure switch is an input of the ECM. The switch connects to contact J1-24. The switch tells the ECM when the brake control valve is active. The operator activates the brake control valve with the brake pedal. The ECM initiates the elevated shift function. The ECM then cancels the turn around shift function. The switch is located on the foot-operated brake control valve in front of the cab. The switch is open during normal machine operation. The brake control valve is not active. The switch closes to ground when the brake control valve is made active by the operator.
The switch has two contacts in the harness connector. One of the connector contacts is connected to the ECM. The second connector contact is connected to J1-15. The switch is normally open.
The ECM records diagnostic codes with the service brake signal as a CID 0704. A record of the diagnostic code is made while the machine is in operation. The service brake signal must remain open for seven hours or the service brake signal is grounded for two hours.
Retarder Pressure Switch ( D250E, D300E)
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| Illustration 2 | g00382033 |
Retarder Pressure Switch | |
The retarder pressure switch is an input of the ECM. The retarder pressure switch connects to contact J1-25. The switch tells the ECM when the retarder control valve is activated. The operator activates the retarder control valve with the hand lever. The ECM then initiates the elevated shift function. The ECM then cancels the turn around shift function. The switch is located on the right side of the cab below a cover plate. The switch is grounded during normal machine operation (Contact 1). The retarder control valve is not active. The pressure switch opens when the retarder control valve is activated by the operator (Contact 1).
The switch operates the retarder indicator lamp on the dash. The retarder control valve is not active during normal machine operation. Contact 3 of the switch is open. When the retarder control valve is active contact 3 is grounded and the retarder indicator lamp turns ON.
The switch has three contacts in the harness connector. One of the connector contacts is connected to the ECM. The second of the connector contacts is connected to the retarder indicator lamp. The third wire of the connector contacts is connected to J1-15. Contact 1 is normally open (NO) and the other contact is normally closed (NC).
The ECM records diagnostic codes with the retarder pressure switch as a CID 0715. A record of the diagnostic code is made while the machine is in operation. The signal must remain grounded for two hours.
Parking Brake Switch
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| Illustration 3 | g00382132 |
Parking Brake Switch | |
The parking brake switch is an input of the ECM. The parking brake switch connects to connector contact J1-13. The switch tells the ECM that the operator wants to activate the parking brake. The operator activates the switch by pulling on the parking brake knob. The ECM activates the parking brake by activating a solenoid driver. The solenoid driver de-energizes the parking brake solenoid. The parking brake is now engaged.
The ECM inhibits activation of the parking brake until ground speed is approximately 2 mph or less. See Testing and Adjusting, "Parking Brake Function" for more information. The ECM initiates the parking brake function and the ECM cancels the turn around shift function. See Testing and Adjusting, "Elevated Downshift Function" for more information.
The switch and the knob are located on the dash panel in the cab. The switch is closed to ground when the parking brake is OFF (not engaged). The parking brake knob is pushed in. The switch opens when the parking brake knob is pulled out by the operator and the parking brake is ON (engaged)..
The switch has four contacts in the harness connector. Contact 1 connects to the ECM. Contact 2 connects to J1-15. Contacts 3 and 4 are not used.
The ECM does not record diagnostic codes that occur with the park brake switch.
Transmission P2 Pressure Switch ( D250E, D300E, D350E)
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| Illustration 4 | g00382033 |
Transmission P2 Pressure Switch | |
The transmission P2 pressure switch is an input of the ECM. The switch connects to connector contact J1-14. The switch tells the ECM when the P2 pressure is at a specific value. When a shift is made the ECM waits until P2 pressure returns to the specified value before activating the lockup clutch. See Testing and Adjusting, "Lockup Clutch Function"for more information. The switch is located on the P1/P2 test cover on top of the transmission. The switch is open during normal operation. The transmission is not in neutral or shifting. The P2 pressure is greater than the specified value. When the machine is in neutral or during a shift, the switch grounds the P2 pressure signal. The P2 pressure is less than the specified value.
The switch has three connector contacts in the harness. Connector contact 3 connects to the ECM. Connector contact 1 connects to J1-15. Connector contact 2 is not used. Contact 1 and contact 2 are normally open (NO). Contact 1 and contact 3 are normally closed (NC).
The ECM records diagnostic codes with the P2 pressure signal as a CID 0602. A record of the diagnostic code is made while the machine is in operation. The diagnostic code is recorded if the status of the P2 signal does not change during three consecutive shifts.
Differential Lock Switch
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| Illustration 5 | g00384844 |
Differential Lock Switch | |
The differential lock switch is an input to the ECM. The differential lock switch connects to connector contact J1-34. The switch tells the ECM that the operator wants to activate the differential lock. The ECM checks for certain conditions and parameters. The ECM then determines if the differential lock should be activated. The switch is located on the floor of the operator compartment.
The differential lock switch has two contacts in the harness connector. One of the connector contacts is connected to the ECM. The other connector contact is connected to +battery power. The differential lock switch is a momentary switch that is normally open.
The ECM does not record diagnostic codes that occur with the differential lock switch.
Cross Axle Lock Selector Switch
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| Illustration 6 | g00518764 |
Cross Axle Lock Selector Switch Schematic | |
The cross axle lock selector switch is an input of the ECM. The switch connects to connector contact J1-23. Ground is at J1-15. The switch tells the ECM that the operator wants to enable the cross axle lock solenoids. The operator activates the switch by toggling the rocker switch. The cross axle lock will only engage if the differential lock is engaged. The ECM activates the cross axle lock by activating a solenoid driver. This action energizes the cross axle lock solenoids.
The selector switch is used to determine if the locks should be engaged. The cross axle lock will disengage if the machine speed reaches 10 mph. The cross axle lock will NOT engage if the machine speed is below 10 mph.
- The cross axle lock selector switch is ON: When the operator activates the differential lock switch, the interaxle lock turns ON. The front cross axle lock, and the center/rear cross axle lock will also turn on. If the diagnostic code overrides and the speed overrides are not active the solenoids will lock the drive train.
- The cross axle lock selector switch is OFF: When the operator activates the differential lock switch, the interaxle lock turns ON. The front cross axle lock is OFF. The center/rear cross axle lock is OFF.
Note: If this software is placed on a machine that does not have the cross lock selector switch installed, then the front and the center/rear cross locks will not function.
The ECM does not record diagnostic codes that occur with the cross axle lock switch.
AT Shifter
Hold Toggle Switch
The hold toggle switch is an input to the ECM. The hold toggle switch connects to the ECM through connector contact J1-19. Ground is at J1-15. The hold toggle switch tells the ECM that the operator wants the transmission to stay in the current gear. The ECM then places the transmission on hold.
The switch is located on the shift lever. The switch is under the operator's thumb. This switch is a momentary switch. The operator activates the switch by pressing the switch and then releasing the switch. When the switch is operated the value of the hold function is changed to a new value.
Top Drive Gear Switch
The top drive gear switch is an input to the ECM. The switch connects to the ECM through connector contact J1-20. Ground is at J1-15. The top drive gear switch limits the highest gear that is engaged by the transmission. The ECM then restricts the transmission from shifting past the indicated top gear.
The switch is located on the shift lever. The switch is located under the operator's thumb. The operator activates the switch by pressing the switch and releasing the switch. The hold function is changed to a new value when the operator activates the switch.
When the drive gear changes it is shown on the monitor display.
The top drive gear is lost every time the control is turned off. Each time the control is powered up the top drive gear is set to the maximum gear.
Steering Pressure Switch
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| Illustration 7 | g00385532 |
Steering Pressure Switch | |
The steering pressure switch is an input of the ECM. The switch connects to the contact J1-27. The switch tells the ECM the primary steering pressure. When the steering pressure is low the ECM will activate the secondary steering pump.
The switch has a normally open contact and a normally closed contact. One side of the normally open contact is connected to the ECM the other side is connected to ground through the ECM. The last connector contact of the switch is not used. The switch is normally open.
The ECM does not record diagnostic codes that occur with the steering pressure switch.
Park Brake Pressure Switch
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| Illustration 8 | g00518275 |
Park Brake Pressure Switch | |
The park brake pressure switch is an input of the ECM. The switch connects to connector contact J1-26. The switch tells the ECM when the parking brake is engaged. Connector contact 1 connects to the ECM ground J1-15. Connector contact 2 connects to the ECM J2-26. Connector contact 3 is not used. When connector contact 2 is closed (connected to ground) the parking brake is released. When connector contact 2 is open, the parking brake is engaged.
The ECM records diagnostic codes with the parking brake as a CID 0627. A record of the diagnostic code is made while the machine is in operation. The switch signal must remain grounded for seven hours or the signal must remain open for two hours before a diagnostic code is logged.
Key Start Switch
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| Illustration 9 | g00291705 |
Key Start Switch | |
The key start switch is an input of the ECM. The switch connects to connector contact J1-40. The switch tells the ECM that the operator wants to start the engine. The ECM then initiates the neutral start function. See Additional Functions, "Neutral Start Function" for more information. The signal is open during normal operation. The switch will close to +battery when in the START position.
The switch has four terminals. Terminal "S" connects to the ECM. Terminal "B" connects to battery voltage. Terminal "C" connects to the engine shutdown control. Terminal "R" connects to the main relay.
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 ECM does not record diagnostic codes that occur with the key start switch.