1040 Line 1 is shown as greater than taxable income on w-2

Are there any letters by 1040 line 1? Like SCH or DCB or HSH?

Did you get any 1098 forms? SCH by 1040 line 1 Wages is taxable scholarship income and then the amount.
See FAQ https://ttlc.intuit.com/questions/2172062-why-is-my-scholarship-taxable

and how Turbo Tax calculates 
https://ttlc.intuit.com/questions/1901084-how-does-turbotax-calculate-line-7-form-1040-1040a-and-line-1-1040ez-wages

Taxable scholarship is any grant or scholarship amount that exceeds qualified educational expenses (tuition, fees and for undergrads, course materials[books]). Loans are not scholarships and are never taxable

OR
HSH is for Household Help
DCB means Dependent Care Benefit

Or do you have any 1099R forms with code 3 in box 7?

Thanks for your reply.

I found out that the problem was that I entered the wrong code in Box 7 of an 1099-R form. With this correction Form 1040 line 1 is now exactly equal to the sum of W-2s. This was difficult to troubleshoot because TurboTax's supporting form link took me to the list of W-2s. 1099 that was included in this sum was not listed at all.

Yes 1099R was my last sentence.  What code is in your 1099R?  Did you enter it wrong?  Don't change it if it is right and a 3.  And actually  showing up on the W2 line is better.  You can get EIC credit for it.