PLATE 1869166 - Caterpillar

System Operation Description:The Electronic Control Module (ECM) has the ability to automatically prelube the engine before cranking. This prelubrication may increase the life of certain engine parts. The ECM will prelube the engine, when the Engine Control Switch (ECS) is placed in the START position. The ECM will prelube the engine, when the ECS is placed in the AUTO position and the remote start/run/stop switch is closed. The length of time for the prelube cycle can be programmed by the customer. The prelube cycle will end when the prelube pressure switch closes or if the customer programmed time ends. The engine speed must equal zero rpm before the prelube will begin.The prelube cycle has the following status codes: "OFF", "ON", "COMPLETED" and "DISABLED".The "OFF" status is entered when the engine control is first powered up with the ECS in the STOP position.The "ON" status is entered when the ECM is on with the ECS in the START position.The "COMPLETED" status is entered when the engine prelube duration is reached or when the engine prelube's pressure switch is activated.The "DISABLED" status is entered when the engine prelube duration is programmed to 0.The prelube function will be aborted when one of the following conditions occur:
The prelube pressure switch is activated.
The user defined engine prelube duration has been reached.
The operator activates the prelube override switch.When the ECM senses the ECS in the START position, the ECM will activate the output driver for the "PPR1" relay. When the "PPR1" relay energizes, the normally open contacts of the "PPR1" relay close. This allows current to flow to the prelube motor. The prelube motor activates the prelube pump. The prelube pump builds pressure in the engine's lubrication system. When the prelube pressure switch closes as a result of the increased pressure, the ECM input for the prelube pressure switch is taken low. The ECM then knows that the prelube pressure is adequate. The ECM will begin the starting sequence.
Illustration 1 g01193921Test Step 1. Check for Connector Damage.
Turn the circuit breaker for the battery to the OFF position.
Turn the