D4 flashing after radiator replaced in 95 honda accord?

Took my 95 Honda Accord to a repair shop to have my radiator replaced. I got home the next day turn my car on and might be four light was flashing I put it in drive I can go a little bit but I can tell that the transmission is not acting properly I haven't had a issue with his car before transmission wise this is the first time this has happened but only after I changed the radiator replaced the radiator at the repair shop. I have read in other fourms that a flashing light means there's an issue with the transmission just trying to see if anyone else had this issue after changing the radiator and was wondering how much this cost to fix or if it's a simple fix our parts need to be replaced any help would be greatly appreciated just did the engine swap on this car and my funds are limited thanks

I just find it difficult to relate the radiator (cooling system) to the transmission.
It is possible that it could be just coincidence that another problem came about just right after the radiator replacement.

Get the codes to diagnose why the light is on.

The shop that did the radiator replacement should be able to find it right away and likely fix it at no cost - they probably left something loose. In any case, it is good to let them have first shot at it. I was service manager of an avionics shop for 8 years and I always appreciated the opportunity to make good on a goof.