Just thought I'd post my fix for the continuing problems I've been having over the last few years with my '92 accord. Thanks to everyone for your help.

S light coming on when driving with car locking in 3rd gear. After stopping and switching off, most times the car wouldn't restart for a least 10 min - or days! At other times the car would be running fine, I'd go intop the shops etc, get back in and the car wouldn't start and S light would be flashing. Pulling the codes each time would give at least 6 errors, but these could change each time after clearing them and resarting - or trying to restart.

This was getting worse to the point where I wasn't game to use it.

So, I did the near-new TCU. It looked fine, but I replaced all the caps. There were a couple of sus looking dry joints on some resistors so I re-soldered them. Put it all back together - yahoo! fired straight up. Drove it for a day and then next morning jumped in and NO START! S light flashing again. Did some more research around the net and decided to take out the NEW main relay (it was replaced along with the TCU 4years ago). Opened it up and FULL of dry solder joints. I re-soldered it - took about 10 minutes. Back together and it's now been 3 weeks with NO problems. No S light, no error codes and running better than it ever has.

So looks like it was proabably the main relay! Seems you can't rely on the genuine stuff! Anyway, the car is running great and I'm happy again.