I have a 1992 Honda Accord wagon with 2.2l PFI. So quite a while ago the TCU went bad, was diagnosed that way by a transmission shop, and I found someone to rebuild it. I put it back in the car and everything worked fine... for awhile. Then, the D4 light turned on and stayed on, and the car only had 2 gears, 2nd and 4th, and I had to shift manually. I took it to another shop, who pulled the computer and sent it back to the guy who had done the rebuild. He refunded my money, saying that the juice from the leaky capacitors had fried one of the chips in there and there was nothing to be done, the unit was not rebuildable. So, back in the car it went and I drove it with only two gears for over a year (although not very much or very hard).
FF to the present.
Finally decided to spring for a rebuilt TCU from Rock Auto, it came, I put it in, nothing happened. D4 light is still on, I'm still driving 2 speed manual style. I tried doing the jumper to get error codes, but nothing happens. D4 light is still on, as Scotty says "I'm getting no response, captain!"
Is my new part defective? Any way to tell if this is the problem or it's something else? Help?

 

Try pulling the tcu codes

 

I tried pulling the codes by putting a jumper in the blue plug under the kick panel and turning the key on, as I have read in several other posts. However, nothing happens, the D4 light just stays on solid.

 

then you probably messed up the transmission by driving it like that for so long. check trans fluid. make sure it doesn't smell burnt or anything funny. should look cherry red. not dark or black.. pray man just pray

 

Well, it's pretty red, smells a little burnt, and there is a little bit of grey material in there.

 

Grey material, not good.

 

CB Accords diagnostic connector does not have a home and floats in space. Make sure that the diagnostic connector is not corroded or dirty. Verify the contacts are clean, use a piece of solid copper wire as a jumper. Verify that the jumper is working by checking your ignition timing with a timing light. If the ignition timing is adjusting then the ECU is not in diagnostic mode and you will not pull the codes.

What happens when you select D1?
Have you verified the connector to the TCU/ECU are clean and properly installed?

 

Well, I haven't checked with a timing light, but, none of my connectors are corroded, in fact, the whole interior of this car is in really good shape. There's no corrosion on any of the plugs, and I've jumped the blue plug before with a paper clip and gotten error codes off of it, with the first TCU I mentioned that I had fixed.

D1 gives me second gear, D2 gives me second gear, D3 and 4 give me 4th gear.

 

Measure voltage between A8 and Green terminal and body ground. Is there voltage?

No. Replace AT control unit.

Yes. Measure voltage bwteen the GRN wire at the gauge assembly to body ground. Is there voltage?

No. Replace faulty shift position indicator.

Yes. Repair short to power source on GRN wire between A8 terminal and gauge assembly.

 

Thanks, are you making referance to wires on the plugs going into the TCU?

 

Yup. Terminals are labeled.