PISTON 9U9485 - Caterpillar

Illustration 1 g02454756
Illustration 2 g02452854
Start Function component connectionsThe Machine ECM will control the engine start function based on the status of the Key Switch "Start" input. When the ECM detects system voltage on the input circuit, the ECM will energize the Starter Relay if the following machine conditions are correct.
The engine speed is 0 rpm.
The system voltage is less than 36.0 VDC.
The left armrest is in the raised position.
The ECM internal "key override" function is not active.
There are no active diagnostic codes for the Armrest Position Switch or the Service Brake Pedal Limit Switch.The ECM key override function will disable the Starter Relay output when the engine speed is greater than 400 rpm. The override function protects against accidentally engaging the starter motor when the engine is running.When the machine conditions are correct and the key switch is turned to the START position, the ECM will energize the Starter Relay. Turing the key switch will allow system voltage from the 60 amp Starter Relay Fuse to be directed to the Starter Motor Solenoid through the Starter Relay contacts.When the Starter Motor Solenoid is energized, +battery voltage directly from the batteries is connected to the starter motor terminal. This results in the starter motor cranking the engine.If the Machine ECM is faulted, the Key Pad Guidance area on the Operator Monitor will indicate that the Back Up Mode is available. The Back Up Mode allows the machine to be steered to a safe location when immediate service is required. To activate the Back Up Mode, the operator must select Back Up Mode from the Key Pad Guidance are on the Monitor. When the Back Up Mode is operational and the key switch is in the START position, system voltage will be directed through the switch contacts. The Starter Relay will now be energized.If the left armrest position switch or the service brake pedal switch are faulted, the ECM will not energize the Starter Relay.