D4 light on my 97 Civic EX Automatic (115k miles on it) starts flashing as soon as I turn on the keys.
Also I feel a sudden jerk when changing from N to D4. After that it jerks when shifting from at lower speeds. At higher speeds everything is smooth, it again shifts hard when accelerating down on low speeds.

Searched the forum and seems like that it could be a sensor issue.
Any ideas what could be wrong here?
Thanks!

 

You can pull the D4 transmission code just like a CEL code by jumping the service connector or using a scan tool.

 

The code is 1 long flash followed by 16 small flashes, that means 16.
Also I looked under the car (didn't put it on jack) and see some connector dangling in the center (more towards the left side though) . Attaching the pic of the dangling connector.
On Sunday, while backing it from a parking lot I heard some noise, probably some connector brushed against the curb edge. ( as I when I parked my front part of car was over the curb.)

Looking at manual code 16 means Linear Solenoid. Also want to clarify that my Check Engine Light (MIL) is not On.

Could you please tell if that part in picture is just the connector for Linear solenoid or its completely broken because of backing on the curb.

 

Code 16: Fuel injectors What book are you looking at?

I don't think you have the right code.

Recheck it:
Short flashes are single digits (1/2 second)
Long flashes are 10's (1 second)

Or, go to AutoZone and have them scan your car for free.

Edit: That plug looks like the wires have been torn out. Open your hood, look for that connector from above. Then look around and see if there are wires that are loose and dangling. Take pics.

 

I read the code right from the car, its 1 long flash followed by 6 short flashes as I did it atleast 5 times to be sure.
I might have looked it wrong in the manual though.

I got civic manuals from RonJ's signature link http://hondatech.info/downloads/Auto/Manuals/Civic/

I will look at the conenctor again from above once I go home


Also attaching relevant pages from manual

 

I just can't see how a code 16 wouldn't throw a CEL and cause your rough shifting is all.

Edit: looking at the wrong code 16... service manual does say Linear Solenoid. On page 505 "Honda Civic (96-98) service manual", go through the steps for testing the solenoid. Starting with measuring the resistance at the connector.

 

I took the picture of connector by opening the hood and pulling the connector, It looks like a 2 wire connector, Wires are White and Red. Looking at manual it seems like a connector for Linear Solenoid Valve but I am not able to figure out where it is actually on the car,
Can I access it by opening the hood or it can only be accessed from under the car?
I am just thinking will just connecting it again fix the problem?

Your expert advice appreciated.

 

^^That's what the linear/control/shift solenoid looks like^^

It should plug in right behind your hand in that picture actually. Look around, you're very close.

If plugging it in doesn't fix it, and the trouble shooting steps on pg 505 reveal a dead solenoid, rockauto.com has one for 132.89.

Definitely do the trouble shooting steps and let us know what happens.

 

Thanks Norbster, but this solenoid has blue and green color wires. And my connector has white and red wires, I am thinking that these 2 might be different solenoids.

 

Were you able to find where the connector hooks up on your car? Right now, the colors of the wires don't matter. Just use the image as a reference for what the solenoid looks like and if it's hooked up.