My 01 Bonneville shifts kinda hard when heated up but no engine light and i get code p1811 how do i fix only 125,000 miles

What is your question?

I hear a whining noise like low power steering fluid and slight burning smell it slips when hot should I flush trans fluid and get new filter or just new pressure solenoid

What makes this problem better or worse?

It's worse when engine is hot

How long has your 2001 Pontiac Bonneville had this problem?

A week