SOLENOID AS 1118490 - Caterpillar

are two brakes on the machine. The service brake pedal activates the brakes at the wheels of the machine. The parking brake will engage the first and second gear clutch packs simultaneously. This will mechanically lock the transmission in order to prevent any machine movement. The parking brake function is turned on when the armrest is in the UP position. The position switch for the armrest is connected to the ECM at contact J2-23 and J2-28. Also, the parking brake function can be selected by pressing the Parking Brake Switch on the Soft Switch Panel (SSP). When the parking brake is in the engaged position, the LED above the Parking Brake Switch on the SSP will be illuminated.The parking brake function will be ON and the LED on the SSP will be illuminated during the following conditions:
If the service brake is OFF and the left armrest is in the UP position, the parking brake function is turned ON.
If the service brake is OFF and the Parking Brake Switch on the Soft Switch Panel (SSP) is pressed, the parking brake function is turned ON. The parking brake function will be OFF during the following conditions:
If the service brake is ON, the parking brake function will always be OFF.
If the parking brake function is ON and the service brake is activated, the parking brake is automatically turned OFF.
When the service brake is subsequently turned OFF, the parking brake function will return to the previous state.If there is a diagnostic code for the armrest switch, the parking brake will be engaged unless the service brake is activated or machine travel is detected. In these two cases, the parking brake will be turned OFF. If there is a diagnostic code for the limit switch for the service brake pedal, the ECM will not rely on this parameter while the ECM is activating the parking brake.