I have I 1991 Honda Accord. I replaced the transmission but am having same problem. No codes when checked. No lights stay on. Works fine for a few days and then only 2nd and 3rd. Reset by pulling fuse and then ok again for a while. When going up a steep grade and trying to accelerate and putting pressure on the transmission it goes back to having the problem every time. Other things happening but not sure if they are relevant or just other future problems for me to look into are sometimes clicking chatter behind instrument panel and after market car alarm sometimes does not work right? Mostly interested in getting my transmission to work properly.

 

Open TCU and look for burnt resistors and capacitors.

If an aftermarket alarm is installed, verify the wiring to it does not interfere with normal car operations.

If there are engine problems the car will go into limp mode and puts the transmission into 2nd or 3rd gear only.

If you hear chattering check your main relay is not faulty as well.

Does your CEL and D4 light work when you initially turn the car to II(ON)?
If the CEL and D4 lamps are burnt out then there will be no way to check for codes until the lamps are replaced.

Transmission function is greatly affected by engine running condition. If the engine has a fault the ECU will command the TCU into a limp mode of 2nd or 3rd gear.

Click on 'techauto' link in my sig for further diagnostics.

 

fyi, 5 days and running well. D4 and CEL lights work fine but no codes. Took off TCM and one of the resistors was burnt. Disconnected all the car alarm and then replaced with used TCM for the car. All looked the same, but one of the resistors at the bottom of the board wasa smaller than my prior resistor that had blown, not sure if size matters haha. Now has run fine and no issues so far. Keeping fingers crossed.

 

Only concern with resistors/capacitors is if they have the same value.
If your burnt resistor has not discolored too bad, verify it has the same color coding on the body as the replacement TCM.

 

Body is smaller and different as dark brown vs beige which I do not think matters, but looks like the same banding colors are the same in both so hopefully it is good.Thanks