93 honda accord d4 light is on all the time even when trans is in another gear,,when shifting manuelly

SOURCE: 1994 honda accord

The D4 light blinking indicates there is a diagnostic trouble code stored.When a malfunction occurs,the vehicle computer records the code and stores it,then flashes the D4 light to let you KNOW there is a problem.On pre OBD 2 Honda vehicles,1995 and back,Hondas are manual code read,which means you do NOT hook up a scan tool as there is no scan port.The passenger side front kick panel is removed,and a blue 2 wire connector located.Use a jumper wire to short out the connector,then turn the ignition key on,with engine off,not running.This throws the computer into self diagnostic mode,and the D4 or "s" light will flash a series of flashes.The flashes have to be counted,and written down.For example,2 flashes followed by 4 flashes would be a code 24.The code is then looked up with reference material for a description and diagnostic route.Every diagnostic trouble code,has a diagnostic route,for repairing the problem.Again,this informtion,the diagnostic route,is available in reference material from pay sources like All Data Online.After the repair is made,the battery is disconnected to clear the code.Good luck.

SOURCE: where is the tcu in a 2002 honda accord

it is the Transmission Control Unit. you have to find the reason why the TCU is flashing the D4 fault code. not replace the unit. have your vehicle scanned for another code. your transmission or transaxle is giving you a warning that something is wrong .

SOURCE: Transmission in limp mode?

the neutral safty switch tells the comp. what gear is in. when its not working the light wont move and the car will not go threw the gears prop. the switch is nown to go out. it is located on the tranny or down under the shifter

SOURCE: 1992 honda accord stuck in 4th gear

TCU (Transmission Control Unit) Located behind the Passenger Kick panel. it will have a burnt diode inside and can be purchased on ebay for about 79.00 with exchange.

Lugnut61

SOURCE: Honda Accord 1996 automatic transmission D4 light blinks

i wouldn't worry about it its probably a loose wire somewhere as long as it shifts and drives cool hope this helps regards Jim