Why is my 91 honda accord ex s light flashing?

SOURCE: 1990 Honda Accord EX Transmission

possibly due to low trans fluid pressure. the cooler in the radiator may be plugged. to check, disconnect and bypass cooler with rubber line & clamps. drive 2-3 miles. shifting OK now? install auxillary cooler to bypass one in radiator. you can get one at auto-zone $30-$50. may just need fluid & filter change, but more likely it's the cooler. when they get plugged, either one, pressure drops alot.

SOURCE: 96 honda accord ex transmission shift problem

the first common possibilty would be to check fluid level, if the fluid level is good, I would recommend changing the transaxle fluid and filter. if this does not correct the issue, a professional transmission repair person will need to diagnose for you, good luck!

SOURCE: 2000 ex v6 honda accord code p01399

it could be the coil or distrubutor cap

SOURCE: 1999 Honda Accord EX won't shift out of park. It

If you press the Break pedal and the shift button does not engage, Your Solenoid did not activate to release it out of park. either the: solenoid is out - Bent levers - Solenoid harness disconnected - Break activation wire may be damaged. this piece is easy to replace as it sits on the right side (passanger side) of the shift lever. remove center console cover to access the soleniod which is held on by two 10mm nuts. and a C- clamp

SOURCE: po740 code, 1997 honda accord ex 4cyl. 2.2

The error code is basically confirming what you have already found that the transmission is slipping, specifically that when the torque converter locks up on a gear that there is not a significant drop in engine revs i.e. slippage (the lack of engaged drive whilst the transmission is shifting between gears allows the engine to rev a little more freely and the sensor looks for the reduction on engine revving when a gear is engaged). First check the transmission fluid on the transmission dip stick; do this with the car running in 'park'. Firstly is reading 'full'? if not consider topping it up via the transmission dip stick tube. Secondly what does the fluid look like? It should be healthy pink, if brown and burnt smelling this indicates wear and old fluid and this will require a drain and replacement of transmission fluid along with the transmission filter. The torque converter clutch brake band has worn down or it may be that it can be adjusted to compensate for this wear. Adjusting such things should left to the specialists. If the car is still fresh from the dealer I would expect them to repair/fix the fault as a good will measure. This is purely a wear issue and not one due to abusive use of the car.