james007

Hi everyone. Great site, you all have already helped me fix a couple problems with my vehicle.

Here's my situation. I have a 1993 Accord LX auto, and after driving it for a few minutes, the D4 light begins to blink. This always occurs when shifting from 2nd to 3rd, or from 3rd to 4th (i can't remember which), and the shift feels very rough. Like a quick rumble. Then the D4 begins to blink, and then the engine speed will not exceed 2100, except in 1st gear. So at this point, 1st acts normally, and 2nd, 3rd, and 4th all climb slowly, given the 2100 engine speed limit. I should also say that the rough shift only occurs at the moment when the D4 goes from normal to blinking. When first starting to drive, or after I reset the TCU and the D4 is not blinking, the tranny shifts perfectly.

So, after pulling the TCU code, I get a 7, indicating shift control solenoid A. Both solenoids ohm at 16.4. So my next course of action is to remove the solenoids and give them a thorough cleaning. My question is, can the shift control solenoids be removed from the transmission without removing the trans fluid? Also, to what degree can the solenoids be disassembled? Are they difficult to reassemble?

Thanks for your help.

james007

Information update...

I put 12V across both solenoids. One sounded slightly weaker than the other, but not by much. I also pulled my TCU (PXO-722) and tested the solenoids through the harness, as per helms. At the wiring harness, I get no voltage across either solenoid with the ignition on, both ohm at 15.4, and when the solenoids' connector is removed, i get no continuity at the harness. I opened up my TCU and everything looked pristine. No burnt resistors, no leaking caps. From what I've read though, my model TCU is pretty robust.

Are there any other possible causes for my car's condition?

davey5300

did you clean the selnoids yet?

fastlane2

Just remove them with a oil pan under the egine/trans. I'd also check your grounds, one at the bottom below battery, I mean remove and clean with sand paper etc.

james007

I removed the solenoids. Gasket and screens were clean. I put 12v to both solenoids to open them up and sprayed them through pretty liberally with carb cleaner until only clear liquid came out. Not much dirtiness came out.

So anyway, I put them back on and reset my tcu and it drove great for almost 3 days. One more day, and i'd have declared the problem solved. However, today my blinking D4 returned, throwing the same code 7. I pulled the fuse to reset, drove for an hour, and it came back again. I've noted though, since i've cleaned the solenoids, i can drive it much longer before it triggers the error.

fastlane2: are you referring to the engine ground?

fastlane2

Yes becasue I had a similar code issue and it was due to the grounds being dirty/rusted

Rhikyle83

How do you clean the solinoids and how can u tell if the grounding is bad

fastlane2

Are the connections after unbolting them dirty aka rusted etc.

mlw202

your better of changing the solenoids theres two differnt sets the ones that are on top is tcc lock up the bottom ones are shift cleaning only works sometimes