SHAFT 8P7834 - Caterpillar

Torque Converter Lockup Clutch Solenoid (Attachment)
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The solenoid functions as a proportional valve. The solenoid modulates hydraulic pressure to the lockup clutch. The ECM increases the current to the solenoid valve and the hydraulic pressure at the lockup clutch is increased. The ECM decreases the current to the solenoid valve and the hydraulic pressure at the lockup clutch is at a minimum. The ECM will log a diagnostic code of CID 0679 for the lockup clutch solenoid.Autolube Solenoid (Attachment)
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The solenoid activates the autolube pump. The solenoid deactivates the autolube pump. The ECM will log a diagnostic code of CID 0378 for the autolube solenoid.Relays
Start Relay
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The relay is used in order to energize two other start relays. One of the relays energizes the start solenoids. The other relay energizes the starting motor. The ECM will log a diagnostic code of CID 0444 for the start relay.Relay for Heated Mirror (Attachment)
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The relay is used in order to activate the function for the heated mirror for five minutes. This relay is driven by a sinking driver. The relay for the heated mirror does not have a diagnostic.Relay for the Compressor Clutch
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The relay activates the cooling fan for the condenser. The relay is driven directly by the Power Train ECM. The ECM will log a diagnostic code of CID 2671 for the relay.Relay for Disabling the Powered Access Platform
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The relay is driven when the parking brake is disengaged. The relay is driven when the direction switch is not in the neutral position. The relay does not have a diagnostic.Backup Alarm Relay
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The backup alarm relay is driven by the ECM. The relay activates two backup alarms. The backup alarm warns nearby personnel that the machine's transmission is in the reverse gear. The two backup alarms sound whenever the direction switch is in the reverse position. An open in the circuit for the relay does not cause a diagnostic code. The ECM will log a diagnostic code of CID 0144 for the backup alarm relay.Indicators
Ground Level Transmission Lockout
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The LED is used to indicate that the ground level transmission lockout is active. The indicator emits an amber colored light. The indicator requires 24 VDC in order to function properly. The indicator is active when the current is between 8 mA and 16 mA. The indicator is not active when the current is between 0 mA and 8 mA. This is not a push to test LED.Autolube (Attachment)
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The LED is used to indicate that the grease level for the autolube system is low. The LED is located in the deluxe service center if the attachment is installed.Additional Outputs
Backup Alarm
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Two backup alarms are on the machine. The backup alarm sounds when the direction switch is in the reverse position. The machine may be backing when the alarm sounds. The ECM will log a diagnostic code of CID 0637 for the backup alarm.