2000 HONDA ACCORD V6 D4 LIGHT FLASHING AFTER I TRY TO SOLDER THE MOTHER BOARD BECAUSE MY DASH BOARD LIGHT WAS OFF THE CAR WAS RUNNING GOOD UNTIL I DID THAT NOW IT SLIP IN D4 AND D3 BUT RUN GOOD IN D2 AND D1 COULD YOU TELL ME WHAT WENT WRONG I NEVER HAD A TRANSMISSION PROBLEM TILL NOW IT SHIFT HARD GOING TO D NOW

Check the fuel pump relay solder joints.

these cars are known for bad transmissions , what did you do , why did you play around with the cluster you should never fix something that is not broke , go on youtube , you may have screwed up a wire on the cluster that controls the shifter somehow ,

When it's hot inside your car it causes a solder joint on a little circuit board in your Main/Fuel Relay to loose contact. The MAIN RELAY is up above your gas pedal near the cruise control computer. Almost directly behind the dash vent opposite of your coin drawer. It will be a gray or brownish/orange box with a plug of wires connected to it. Use a 10mm socket (with extensions to reach) to move the metal cruise control unit out of the way and tap the Relay, "Plastic Box", while someone tries to start the car. If you can bring it down into better view you can tap it and start the car if you're flexible.

TO FIX THE PROBLEM: Don't buy a new one, just pry the cover off of it with a flat head screwdriver and look close where all the sharp pins are sticking up on the board to find the broken solder connection(s). Heat the faulty pin with a soldering iron until the solder puddles around it and your good to go. The crack in the solder will be smaller than a human hair, look close & wiggle it and you'll see the loose connection. There is usually no need to add solder, what is there is enough, it just needs melted again. Works every time on the Accord, Prelude, Civic and Integra.

There's a Gray Colored Box under the dash just above the accelerator. It can be removed by unplugging its wiring, & removing 1 bolt. Removed circuit board from Box, & repair solder connections by a relay.

Ray

You will have to flash code the TCM (which is on the passenger side floor board) for trouble codes. The TCM will flash the D4 light when it has a stored code.

The D4 indicator light flashing indicates that your car's computer believes that there is something wrong with your transmission.

This is what the manual for your 2000 Accord says:

The "D4" indicator comes on for a few seconds when you turn the ignition switch ON (II). If it flashes while driving (in any shift position), it indicates a possible problem in the transmission. Avoid rapid acceleration and have the transmission checked by an authorized Honda dealer as soon as possible.

Sometimes this will mean that you are simply low on transmission fluid, but you really should have it checked.

Hope this helps you.

could be speed sensor. the light is on because the trans doenst know the vehicle speed.

i have a 92' honda accord lx, it has a problem of the D4 light flashing and the car wouldnt start, but i could wait a few minutes and try again and it would start.

you have a transmission fault the D4 light blinks to tell you that there is a transmission problem when the light is blinking the transmission computer put the transmission into limp home mode so it will not shift normally and you should try not to drive it very far when it gets to this stage you need to have the transmission codes check to pin point the problem

okay everybody...i did it myself....replaced the main relay and the TCU box..but i didnt use another OKI manufactured TCU..i bought the Denshigiken manufactured one....(this was a 2nd manufacturing of the TCU)....when it first arrived today i opened the module up to check the resistors and capacitors...and noticed the completely different configuration and parts inside...this worried me..but i hooked it up anyways...to my amazement all problems vanished ..and everything works now..(cruise control, shift interlock, D4 light, tranny shift, brake light, intermittent no start, everything that was wrong..must have ran through this stupid little resistor) ......i solved his problem for less than $100.00..and less than an hours work....i can get more of these Main relays and TCUs if someone needs or needs help locating and removing/installing new pieces...email me at [email protected] or call me @816-286-8851..ill be glad to help

Main relay ........$10.00..
TCU................. $80.00...
10mm deepwell ...$4.00