I am having the same problem, have tried to change the keys to make sure they aren't conflicting with other controls but this doesn't work either - the only thing I am able to do is arrest people on the street, cant pull over cars etc
Hopefully someone can help with this
Have installed GTA IV from steam, installed LCPDFR and downgraded to 1.0.7.0 using the guide posted on here. The diagnostic tool shows all green but now when I try to load the game the rockstar game launcher shows code 7002.1 - this must be an issue with something on LCPDFR or downgrade as worked previously.
I have tried a fresh install and it works fine then reinstall LCPDFR and downgraded and once again the same issue appears.
Unsure that any of the logs will show this problem.
Have installed no other mods at this point.
Appreciate any help anyone can provide!