Phil..my bound manual is in the garage and its raining. My cd sevice disk shows some codes but not the one you are mentioning. I do believe the bound volumne shows all codes. If it stops raining, I will check it out for y ou. Your dealer has a copy of the codes. You could call him.
Phil - sorry I've not responded sooner...board seems to have some issues. To the point...I use the bound manual and it lists up to # 33 error code as well as the diags for each. If you're still having the # 13 code, please let me know and I'll post/send you the test procedure as outlined in the manual. Hope that helps!