Joseph:

The Gents are spot on. The test will fail and then exit if the PCM isn't satisfied that the engine is up to temp. Most all of the "test Caveats" are on that Service CD. Look under the PCED tab, select OBDI, select the correct model and go to 7.3 Diesel Diags, section 18. Then Perform diesel diagnostics. Based on a quick scan, they also give a preferred order to execute the testing sequence. I also found a performance sheet good for test execution and any code/diagnostic notes.

For the few tests I have run, I've filled out the relevent sections of that sheet. Like an oil analysis routine, that data allows establishing a trend line to gauge the health of the engine. Though it isn't running perfectly, it is still in the 'healthy' range.