I've bought my 129000 mile LS400 with an intermittent O/D OFF flashing light, comes and goes without logical intervals according to the seller and this has been the case. When the O/D OFF light is flashing, I can feel the transmission isn't shifting as it should. I did a code readout and this was the result:

63 - Open or short circuit in no. 2 solenoid valve
67 - OD direct clutch speed sensor signal malfunction

I've done my research and if it had been only a code 63, I would've probably ordered a set of shift solenoids right away given it's a common issue. My ATF is brownish, not black but certainly not pink, so I will be flushing that either way. It strikes me as odd that these combined codes would both be intermittent, a quick look at the EPC revealed they are both connected via harness 82125-50010, which seems like a prime suspect. Does anyone have any experience changing out this section of wiring? Logically the bad connection should be in the main plug outside of the transmission, but I suppose it's possible the inside connectors deteriorate over time due to the ATF?



Amayama can supply both shift solenoids, 2 speed sensors and the wiring OEM for about 275 USD, so not too bad, but before ordering it seems logical to clean up the main connector first. Is this easily reachable under the car or a pain to get to? I don't have a lift for at least a few weeks so I can't just take a quick look right now. Any tips are appreciated.

And to avoid ordering wrong parts, can someone confirm a euro spec 1990 LS has an A341E which needs 85420-50020 shift solenoids and 90301-11008 speed sensors?

 

I want to GUESS fluid.Im just guessing,the pro's will tell you.

 

Spuds, I've considered that and it will be changed either way. I've only driven the car a handful of times (waiting for registration) and I noticed the problem presented itself more often today than previous days. Those were all dry days, today we've had quite a bit of rain. Might be a coincidence, but I doubt I'm that lucky.

 

If the problems was intermittent and not always, a simple drain and fill of T-IV ATF could guide you to the next step to do.

It would be best to check parts dropping the pan, but according to my experience at many different shops, most of your type of problems were caused by the semi-sticking solenoid which was badly clogged. Contaminants in the dirty ATF disturb the movement of the solenoid plunger.

If so, the occurrence would become less after the drain and fill. Try it again and there'd be no more occurrence. In my experience 2-3 cycles fixed the problem mostly. Sometimes I needed to drop the pan though.

Incidentally, if you want to check the solenoid electrically, you can simply do it using a DC variable voltage power supply unit. I'll write about it if needed.

 

I had this issue in the past. I did a transmission flush with Toyota Type 4 fluid (12-pack off amazon) to see if it would fix the issue, it didn't but I noticed the transmission shifted a lot better when it was cold. Then, I bought new solenoids and used the remaining transmission fluid to top it off. My LS400 has been running and shifting fine for almost 2 years.

 

Yamae & 1on1: I received 12 quarts of Mobil 3309 today, somewhere next week I should have access to a lift and will attempt 3 or 4 drain & fill cycles before deciding whether or not to drop the pan. I did notice one thing: the issue never happens when the transmission is cold, if and when it happens, it's always when the fluid is hot (10 minutes of driving and more). I'll keep this thread updated once I know more.

 

following......

 

I flushed about 8 liters of Mobil 3309 through the transmission today, the "delicate" way: drain pan, fill 1.9L, drive 10 minutes, rinse & repeat.

Findings so far: the problem isn't gone yet, but there is one noticeable difference: in the past, when the O/D OFF light was flashing, there was nothing that could be done to get rid of it. As it stands now, I can floor the gaspedal to get the transmission to attempt a shift and after a few tries, the solenoid will engage and the O/D OFF light will disappear. It feels like it's working itself loose. I give it about a 50/50 chance of fixing itself, I'll have more conclusive findings after driving another 50 miles or so.

 

Thanks for keeping us updated.

 

Thanks for the update.
Reading your above post, I can confirm that the solenoid is not open circuited but I suspect that the line pressure is still not high enough. This may be caused by the clogged strainer or the pressure line is partially blocked by the sludge. In order to completely fix the problem, it may be needed to clean that.

You still have some more ATF and you can do the drain and fill may be 2 more times. When you do it next time, you'd better to drive the car more aiming the lower viscosity of the ATF. 10 minutes is not long enough to be the temperature saturated and the ATF flows well to rinse. Anyway you are mentioning to drive 50 miles and I think it's a good idea to drive longer.

 

Thanks for the additional tips Yamae. I should mention that before doing the first flush, I drove the car 50 miles as well, so the ATF was hot. The 10 minute drive between each flush was more to keep the heat in the transmission and circulate the fluid, but you are right, 50 miles might not be enough to get a conclusive diagnosis. I'll give it a couple of weeks of driving before ordering replacement solenoids.

I also intend to do another code readout in a few days when the O/D light starts flashing again just to see if I still have both 63 and 67 errors or if the 67 has gone away. It doesn't make sense for me to keep flushing the ATF though, the cheapest price for Mobil 3309 or Toyota T IV I could find in Belgium was 11€/L, so for the cost of 10L of ATF I can buy a new OEM solenoid.

 

Hey man im having this same exact problem as we speak ik this thread is old but i was wondering hopefully you could tell me how you fixed this problem

 

update....

 

I'm 99% sure it's the shift solenoids, I have them sitting in the trunk but never got around to it. I decided to drive around for about 1000km with fresh transmission fluid to see if that would resolve the problem, since the LS is one of a dozen "fun" cars I have and not a daily driver, that took a while and I never got around to changing the solenoids. The issue is still present but less than before, which is why I'm 99% certain it's the solenoids. So I'd advise you to do the same, fresh transmission fluid, drive it around for a good while and if that gets you nowhere, swap the solenoids. I guess you could try cleaning them, but given the amount of bolts to loosen to get inside the transmission and the fact that it's sealed with liquid gasket, I figured I don't want to do the job twice so I bit the bullet and ordered the solenoids. I did try inplugging them, checked the wiring plugs for corrosion and reinstalled with some dielectric grease, but that didn't do anything.