Hello my informed friends. A friend just installed a used transmission on a 4cyl 2001 accord but with issues. The car shifts smoothly like new when cold with no jerks at all. It starts misbehaving when warmed up. It will start with jerky shifting on gear 1-2 and eventually end up in limp mode with blinking D4. Codes p1753 and p0730 were pulled. Turning it off and on brings it out of limp mode but it goes back as soon as it wants to shift to 2.
Any advice on how to solve this issue? Is the transmission a bad one? Please help.

 

P0730. Shift Control system(pg 14-89 in FSM)
This code will be set if there are other DTCs set with the transmission relating to shift control. Diagnose P1753 FIRST.

P1753. Torque Converter clutch solenoid valve (pg 14-64 in FSM)

If the original transmission had neither codes prior to replacement then it is most likely a loose or dirty connection to the TC solenoid valves. Verify the trans wire harness was not damaged during removal/installation. If original trans is still available, make sure to remove and retain the various shift valves. If they were working fine then you can use those to aid in diagnostics after locating a FSM.

 

I don't understand, why does it drive well when engine is cold? problems slowly starts as engine/transmission heats up. I just opened the hood and the wiring looks fine and I wonder if it was an electrical problem shouldn't the problem be present even when cold? I just want to be sure before I take any action.

 

just an opinion , but if the shifting is fine when cold then I would concur that the connectors are not faulty.

But the solenoids could still be faulty only after it warms up.

Try transferring all of the accessible solenoids from the original transmission one at a time and see if it disappears.


Now for a suggestion that might not be related. These years are known for their transmission failures...being a used tranny I am not certain the "new" is all that great to begin with. The key problem with them is heat, their original transmission oil cooler is through the radiator which is woefully under sized. Get yourself an aftermarket Trans Oil Cooler and mount it in front of the A/C Condensor. Be sure to BYPASS the original cooler, do not run your new cooler in series with the old. They are cheap about 60 bucks plus extra hoses.

From what I understand the heat wreaks havoc on the clutch plates in the torque converter and the friction material circulates around the orifices until it clogs an important orifice and the tranny is starved of cooled oil. Not good. There is a guy in ebay that sells remanufactured trannys for our year accords for $995, with some internal mods and after market cooler and after market filter...and 2 year warranty...pretty cool.

 

Close but not exactly......

OP - Follow what Mike has posted

 

Ugh don't be so terse, expound so that we ALL can learn. If I'm close , then explain where I am close and where I am not.

 

When cold the PCM most likely has a different shift schedule to prevent excessive wear to the engine and trans when cold. 94-97 AT cars will not shift into fourth until the engine has warmed up enough to prevent wear and damage.
Depends on the cause of the fault. Do the diagnostic procedures on pages 14-64/14-65 to determine if it is the PCM, wiring or solenoid.

You have listed generalities.

Could be a clogged up port, sure.
Could be inadequate cooling, ok.
Could be the transmission just sucks donkey *******, alrighty.

These may or may not be related to his P1753 issue.
But the only way to find out is, to do the diagnostics provided and follow through.

 

Don't want to get this thread too far off tack but here is some light reading for you : Transmission Report: Overheating Honda Converters, Vacuum Testing and More - Sonnax

OP- stay on track with the codes and testing the solenoids and double checking the connectors (clean, tight and on the correct solenoid).