Pretty sure I have a faulty TCU. My light is stuck on D4 all the time and I am stuck in 2nd or 3rd gear (automatic). I have searched online and this seems to be a common issue with this part in this car.

I did remove the tcu and tried to see if there were any "burnt" out resistors or capacitors but I only saw a black gummy substance across a few of them R15, C23, C36, C21, C20 and noticed the top of a couple capacitors being Purplish.

Once I plugged it back in, it worked fine for a day and then "reset" itself. So pretty sure it's the TCU.

I am not a soderer and not sure which resistors/ capacitors I would change so think replacing the TCU is better option. I called up NAPA and they wanted $700. I checked on ebay and I can get one for $100.

I have model # 28100-PXO-731-M1. My questions are:

1) Can anyone recommend an ebay seller or similar?
2) Should I ensure I get the exact same model number? Or should I get a different one? Their descriptions claim it fits a 1992 accord but just want to make sure.

Thanks in advance

 

I once used a TCU from a 95 Accord to test my trans in my 92 Accord wagon it shifted fine but the D4 light would not stop flashing. As long as it comes from a 92 or 93 you will be fine does not matter what model. the 90& 91 have the sport button so they are different. I have a 28100-PX4-921 TCU in my garage Pm me if u r interested as i sold my 92 a year ago and dont need the TCU any more.

 

If your D4 light is ON then a hard fault is the problem.
Go over to your passenger kick panel, find the blue two wire test connector.
Jump the connector with a paper clip/small gauge wire. Turn the ignition to II(ON) and read the blinking code off the D4 light.

 

hey Mad Mike,

I tried jumping the blue connector as you say, but could not get it to work. I used a wire and shoved one end in each of the holes on the blue connector turned the ignition to on and nothing blinked. I read that sometimes it sends a code and sometimes it doesn't?

Maybe a paper clip would work better?

I saw a video where a guy created his own "male" short with the other end of the blue connector but not even sure how to make this.

 

Use a paper clip, and one side of the blue connector works better than the other.