Hello Honda Accord Forum,

I just inherited my mom's 1993 Honda Accord LX. One owner, a sweet little old lady, and the vehicle lived in a garage for all of its life. Only 94k miles.

The D4 light remains on constantly. Is this a sign of the usual Transmission Control Unit having gone bad?

Thank you,

Gerryz

 

Congrats on that nice Accord and welcome aboard! Looks like you got a low mileage beauty. Where can we look up the pics?

 

I moved your posts to a forum for a response to your problem.

Suggest shorting the service check connector (blue 2 wire connector usually under glove box) and see which codes are flashed by D4 light. See DIY forum for guidance on procedure. See following video for help. Post codes for further help.


good luck

 

Thanks Carid and Texas Honda. Indeed, that was a Texas Honda (San Antonio), and now it is a Virginia Honda.

Carid, as soon as I make the vehicle a bit more presentable, I will post pics. I think this baby hit a few cacti or something of which I was unaware. Glad that the vehicle is safely in my garage where it can get the TLC it deserves.

In any event, after doing some investigation I think that I have TCU issues. Apparently, it's very common among this model year.

Other items include:
* General appearance and bodywork
* Door switches on the driver's side (no interior lights or chimes)
* Broken windshield wiper fluid bottle
* Frozen motorized antenna
* Plus whatever I will need to do to ensure that it is up to Virginia safety and emissions.

Wish me luck!

Gerryz

 

Please check the codes just to be sure you don't have an actual issue with a sensor on the transmission.

People too often assume they have the same problem as some else. They possibly replace a good working part with a used part (a new TCU is $$$), then they have the same problem and possibly new problems. Then we have to rule out the replacement part, then move on to fix the original issue.

Just take your time and do some basic diagnosis. This will save you time, money, and frustration to get the car working.

The door switch is easy to remove and test with a volt meter to make sure you don't have a wiring problem.

I've repaired my antenna and it can turn into a pain to actually repair. I'd probably put that low on the priority list.

 

Thanks PAhonda. Indeed, I will check the codes before getting any further on this. You are quite right.

The door switches are indeed simple, and I hope that the problem lies there.

Oh, and the AC runs, but does not feel very cool. I wonder how anyone could have survived a San Antonio summer without it.

Gerryz

 

Thanks everyone.

I dropped off the Accord at my usual mechanic -- I don't feel qualified enough myself -- and he tells me that indeed the board for the TCU has gone bad. I ordered a new TCU from Foreign Auto Computer Repair.com for $195, shipped directly to the mechanic shop. He tells me that I should be good to go as soon as he checks it himself and puts it in.

I was relieved that for a car of this vintage, the Virginia emissions standards do not apply. As long as no blue clouds emanate from the tailpipe, I will have no problems with registration in this state.

Insofar as the bodywork necessary for the hood and front bumper, I figure that a car bra will hide everything quite nicely.

Thanks again for all the support.

Gerryz

 

Not sure what body issues you have with the front. The bumper is plastic, so no risk of rust. If you have bare metal on the hood or signs of rust, I'd spray some of that rustoleum rust converter into a plastic cup, and use a small brush to seal those spots.

 

Thanks everyone. The transmission is shifting smoothly, thanks to the new TCU. The engine and transmission deliver decent torque, and the pickup is quite adequate.

My next issue is a rough idle, that even makes the steering wheel rattle when the vehicle is stopped. I can switch it into Neutral or Park, but if it is in any Drive position, the vehicle shakes.

Any suggestions for that one?

Thanks!

 

A good cleaning of the throttle body - get both sides of the butterfly - and IACV never hurts anything. I suspect the IACV is a bit dirty and causing the issue....but that is a pure guess.....it will cost a can or two of carb cleaner, some rags and a bit of your time to find out

You could do this as you take care of the other tune up items - plugs, cap, rotor......you did just get it so unless you can prove without a doubt they have been replaced recently, I would change them just so you have a base line.