Hello, I have a 2002 Acura TL-S and one day a P0740 came up, it says Automatic Transaxle Lockup Clutch System Malfunction. Engine ran great still and the transmission still shifted smoothly. Few weeks later I took it for a drive and it seemed to shift out of gear mid-drive so I pulled off and parked it at a friends house. Later that night, I drove it home at about ~20mph with seemingly no issue except it wanting to shift. Scanned it again and a P0730 had come up, Automatic Transaxle Shift Control System. Between the two, my BlueDriver scanner recommended replacing the countershaft speed sensor so I pulled one from a junkyard, unsure if the transmission is dead/dying, started it up with the replacement and the engine was revving up and down when it had been fine before the sensor replacement. During a few drives, it seemed to shift fine for a short while before seemingly being confused what gear it's in. Manually shifting gears it seemed to do well but still occasionally slipped up. Eventually it came up with a P0505 Idle Speed Control System. I'm starting to wonder if the PCM is my issue.

TLDR; Transmission shifting funky, replaced countershaft speed sensor, suddenly idle air control problem. Edit: Car has 250k on it.