Gas dryer no heat in Perm Press cycle

GE standard gas dryer about 7 years old. It has 3 cycles: Perm press, cotton, and timed. When on Perm press, the gas never ignites, however in the other 2 cycles the gas comes on fine. What could it be? Timer, moisture sensor?
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Site Timeline is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.