Engine Pre-Lube Monitor

Background

In some cases the EMIT panel handles both engine pre-lube and compressor pre-lube, such as if there is not a 3rd party ECU. More commonly the EMIT panel will handle the compressor pre-lube process and the engine ECU (e.g. CAT ADEM) handles the engine pre-lube. This article only applies to the case where the EMIT panel does not run the engine pre-lube.

As part of the start sequence after the compressor pre-lube completes the EMIT panel signals the engine to start and switches to "Waiting for [ECU] to start..." and waits for RPM to appear. During this state the engine ECU should pre-lube, crank, and run the engine. In some cases the engine might have pre-lube disabled and as soon as the engine is signaled to start it will skip straight to cranking. A special alarm has been added to try and catch this case, which is covered in this article.

Using the Engine Pre-Lube Alarm

The panel software should be at these versions or newer:

• DCT: 1.67.532
• Brain: 3268
• EDT (optional): 2898

Once the DCT and Brain versions are verified to be up to date, the alarm can be turned on under Settings - Brain - "Misc Settings" - "Require engine prelube". Once this is enabled the Brain will expect the engine to be pre-lubed.

Logic

When the ECU is triggered to start and the state changes to "Waiting for [ECU] to start..." the Brain will expect a minimum of 15 seconds to pass before the crank is detected. If a crank is detected sooner it is assumed the pre-lube is turned off and the start sequence will abort and the panel will display the fault "Engine prelube was expected but was skipped or disabled".

Early Abort

Ideally if pre-lube is disabled we don't want the engine to crank at all since it could cause damage. If the engine is an ADEM 3 and the EDT is at v2898 or newer the alarm may be able to abort before cranking. If the engine pre-lube is disabled or the engine pre-lube timeout is set to 0 the EDT will detect that pre-lube won't occur and report it to the Brain. The Brain will then abort the start immediately before even attempting to signal the engine to start if the "Require engine prelube" setting is enabled.