My guess is that it won't hurt anything. It's only purpose is to let the cat converter to warm up before shifting into 2nd gear. This is to reduce smog.
You can continue to shut off the check engine light everytime it illuminates. You'll just have to fix the problem before your next smog check.
Btw, if it's working it should be slow to upshift. Mine seemed to be doing its purpose. It always held the transmission to a high shift point from 1st to 2nd. It just triggered the fault code. My vacuum hose was plugged and I also decided to change the part. It's only about $27, and it's very easy to replace. It's on the firewell behind the master cylinder.
2001 E430, Bourdeaux Red, Oyster interior.
1973 280SE 4.5, 170,000 miles. 568 Signal Red, Black MB Tex. "The Red Baron".