Hello I’m having an issue with my 1999 Honda Civic DX and I went today to my local Honda dealer to buy a new neutral safety switch and as I put the new one in and start the car the car won’t even crank. So I put the old one back on and when I did that the car runs fine at idle but as I put it in reverse it shifts hard and on the dash the light stays on park no matter what gear I’m in and when the car is in drive it doesn’t want to shift out of first gear and high revs as I drive down the road no matter the rpm it won’t shift. I did notice that the connector pins inside the new one has 13 pins while the old one has 12 but the wire that connects to the Neutral safety switch has 11 metal pins so I’m currently out a car til I can find out why’s it’s doing it. By the way the car is automatic 4 speed with 191,000 miles
Check your ATF level. If it checks out, have a pro check the transmission. So many things could cause these issues (from ECM to shift solenoid), and a pro can track it down for you.
It could also be that the transmission itself is bad.