My problem seems to be a little different than most and I have read several items concerning the sport switch and have tried numerous tips and still cannot figure this one out. The "S" light stays lit continuously in D4 wheher button is depressed or not. It never comes on in D3 whether button is depressed or not. The transmission shifts up and down through all gears and does seem to hold in gear longer when upshifting as described it should do in "sport mode". I have checked the switch with a multi-meter and it is working correctly. Cruise control works just fine. The transmission fluid is bright red and clear - appears to be very clean with no burnt smell. I cannot attest to the brand as I just bought the car a few weeks ago. The check engine light has not come on and there are no codes stored in the tcu - I jumped the connector.
Any help, advice, tips or thoughts will be greatly appreciated. Thank you.

 

since the bulb illumination is controlled directly by the tcu, i'd suspect a bad tcu.

 

It might be possible that TSB 90-039 "S Indicator On, No Downshift" or TSB 2001-017"Trans stuck in High Gear and/or S or D4 light On" applies to your problem. This problem arises from a burnt-out component (resistor I think) on the circuit board. The LED on the AT Control Unit remains lit and will not blink an error code. The interlock control unit (under dashboard above the fuse box) buzzes or clicks. Trans may have other odd shift patterns.

Diagnosis:
1) Depress brake pedal. The interlock control unit stops buzzing/clicking.
2) Reset the TCU by pulling fuse 24 in the underhood fuse box. S-light may go off and trans shifts normally.
3) Removing Fuse 24 does NOT clear the TCU.

Your symptoms may be slightly different, but may be worth a check.

New orused replacement,or repair of TCU is fix.

good luck

 

Thanks to HondaTech and TexasHonda for the information. I will put your ideas to use and see what I can figure out.