Strange check engine light problem

I have a co-worker who owns a 1999 Cherokee with a strange check engine light problem. If he lets the dash finish it's diagnostics before starting, there's no problem. But, if he starts it before the diagnostics are done, he gets a check engine light with a code of P1391.

Here's the history on his Cherokee. When he first bought the Jeep about 6 months ago, it died while on a trip. The dealer replaced both the crank position sensor and the cam position sensor, plus the ECM. Does anyone have a suggestion on what to check or do? The only suggestion I currently have is to clean the connectors on both sensors.

Lee

If thinking the ECM was not installed correctly I think they need to be flashed to match the dash.
It has something to do with the odometer readings that's stored in the Dash and ECM.
I don't think the dash should run Diags every time.

Anyone else have a similar problem?