we have a 2007 Express, DRW, 12,000 lb. bus. It has a PO504 code/Brake Switch circuit 1-2 correlation(symptom 00) The modis gave me the code,but in the troubleshooting program there was no PO504 code listed.Would anyone know what to look for to fix the code. thanks dennis

 

P0504 Brake Switch A/B Correlation DTC

 

thanks canucklehead.I just bookmarked that website,not sure why the modis didn't have any info listed for that code,might need updated again.

 

I do not see that code listed for a 2007 express van. Is your modis software up to date for a 2007 model year? If you enter an older year into the scan tool you can get codes that do not apply.