2004 2.0l won't start help!

[dody]

My daughters 2004 bettle decided about btwo months ago during zero weather not to start has new battery full charge starter cranks engine normally but doesn't fire
sprayed some starting fluid in air intake but got no fire
response at all leads to believe it must be electrical in
ignition (possibly mas sensor?) anyone tell me where to
start looking for cause? Have checked fuses and found nothing ran scan with autoenginuity software and got no
dtc codes is auto with 98k all help and comments appreciated
thanks