I located a service manual that I think is for your washer here.
[link|https://www.appliancefactoryparts.com/content/pdfs/143845-2.pdf|MFL30599151_091007|new_window=true]
Here's the definition for error code 6 according to it.
[quote|format=featured]6 DOOR OPEN ERROR
* Door not all the way closed.
* Loose electrical connections at Door switch and PWB Assembly.
* The DOOR SWITCH ASSEMBLY is out of order.[/quote]
Here's the troubleshooting wiring diagram from the manual.
[document|32049]
And the troubleshooting flow chart for the Door Open Error.
[document|32050]
Hopefully that'll get you going!