CAP 1797380 - Caterpillar

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(7) Cab brake valve (8) Service brake control (9) Secondary brake controlThe service brake pressure switch is located on the cab brake valve.The service brake pressure switch is an input to the brake/cooling ECM. The ECM uses the switch input in order to activate the relay for the brake light. The service brake pressure switch is also used for diagnostics. When the pressure switch is deactivated, the switch is connected to the brake/cooling ECM through contacts J1-12 and J1-46.The pressure switch has a set of normally open contacts and normally closed contacts. Only the normally closed contacts are used for this application. The pressure switch activates at 551 kPa (80 psi) and the switch deactivates at 344 kPa (50 psi).The ECM diagnoses certain failures in the circuit of the pressure switch. A failure is present when the ECM detects a combination of opens and/or ground conditions. The diagnostic code is displayed on the message display. The status of the pressure switch is available to other modules. The information is transmitted over the CAT Data Link. The diagnostic code that is associated with the service brake pressure switch is CID 0704.Lube Pressure Switch (Differential)
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Lube Pressure Switch for the Differential
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Location of the Lube Pressure Switch for the Differential The lube pressure switch for the differential is located on the housing of the differential oil filter.The lube pressure switch for the final drive informs the brake/cooling ECM that the pressure of the differential oil is low. The pressure switch connects to the brake/cooling ECM through contacts J1-12 and contact J1-36. The pressure switch is normally open when the pressure switch is NOT activated. The pressure switch activates at 70 kPa (10 psi) and the switch deactivates at 93 kPa (13 psi).A warning of a category 3 will be logged when the pressure is below normal.Lube Pressure Switch (Final Drive)
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Lube pressure switch for the final drive
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Location of the lube pressure switch for the final driveThe lube pressure switch is located on the housing of the final drive oil filter.The lube pressure switch for the final drive informs the brake/cooling ECM that the pressure of the final drive oil is low. The pressure switch connects to the brake/cooling ECM through contacts J1-12 and contact J1-36. The pressure switch is normally open when the pressure switch is NOT activated.The pressure switch activates at 70 kPa (10 psi) and the switch deactivates at 93 kPa (13 psi).A warning category 3 will be logged when the pressure is below normal.Brake Accumulator Pressure Switch
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Brake accumulator pressure switch
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Location of the brake accumulator pressure switchThe brake accumulators are located on the inner frame on the left side of the machine.The pressure switch informs the brake/cooling ECM that the brake accumulator has pressure. The pressure switch connects to the brake/cooling ECM through contacts J1-12 and contact J1-37. The pressure switch is normally open when the pressure switch is deactivated.The pressure switch activates at 13800 kPa (2000 psi) and the switch deactivates at 12300