GASKET 7W8402 - Caterpillar

System Operation Description:The ECM receives four input signals from the ECS. The input signals allow the control to determine the mode of operation. The ECS can operate in four modes: OFF/RESET, MAN/START, COOLDOWN/STOP and AUTO.When the ECS is set to the OFF/RESET position, the START/RUN/STOP input and the AUTO input are open. The ECM is not powered. Engine operation will stop when the ECS is switched to this position.When the ECS is set to the AUTO position, the START/RUN/STOP input is open and the AUTO input is low. The ECM is powered. If the remote START/STOP Switch is closed, the engine start sequence will begin.When the ECS is set to the MAN/START position, The START/RUN/STOP input is low and the ECS in AUTO input is open. The ECM will begin the engine start sequence.When the ECS is set to the COOLDOWN/STOP position, the START/RUN/STOP input and the ECS in AUTO input are open. After the engine cooldown, the ECM will shut down the engine.If the signals from the START/RUN/STOP input are opposite, the ECM determines that one of the signals is faulty. The ECM ignores the signals until power is cycled to the ECM.If this occurs, the engine must be cranked manually. Use the Manual Crank Switch which is located inside the Electronic Instrument Panel. When the engine is shut down, the ECS must be placed in the OFF/RESET position. This will disconnect power to the ECM. A CID-FMI will be active until the ECM is powered down. The parameter for the Ignition Switch will display "ABNORMAL DATA" until power to the ECM is cycled.If you close the Remote START/STOP Switch, and the ECS is in the AUTO position, the engine will start. The parameter for the switch will display "ON" or "OFF". This parameter is available on the ET only when the ECS is in the AUTO position.
Illustration 1 g00638329
Test Step 1. Check for Connector Damage
Turn the circuit breaker for the battery to the OFF position.
Turn the ECS to the OFF/RESET position.
Check connectors and wiring for the following problems: damage, corrosion, abrasion and incorrect attachment.Expected Result:The connectors and wiring should be free of the following problems: damage, corrosion, abrasion and incorrect attachment.Results:
OK - Proceed to test step 2.
Not OK - Repair: Repair the connectors and/or wiring or replace the connectors and/or wiring. If necessary, replace the ECS. Stop.Test Step 2.