ENG SID 237 11 Start Enable Device Unknown Failure

what does this diagnostics mean on my 1999 Itasca with 275hp cummins? ENG SID 237 11 Start Enable Device Unknown Failure 3/18/14 16:43

I get this often when first starting the motorhome. 3

Re:ENG SID 237 11 Start Enable Device Unknown Failure

The Air Intake Heater is not Fully Heating Up, when Starting the Engine, when it is Cold...

Diagnostics Codes

I have a 1999 Cummins 275 ISB in my 2000 Fleetwood Discovery MH. My VMSpc Diagnostics shows multiple codes and I know many of them are inconsequential. But there are a couple I'm concerned about:

ENG SID 48 1 Injector Cylinder #18 Low Reading 7/11/14 10:54

ENG SID 48 1 Injector Cylinder #18 High Reading 7/11/14 10:54

I have had both of these readings multiple times and the same reason for #19.

Nothing has shown up in the Recent Diagnostic Events window - these all show up in the Notepad file.

Can you tell me what these mean? Is there a place I can find a list of the codes?

Thanks very much for your help.

Pat Curry