Sign in to follow this  
fsuguy

92 Ls 400 Transmission Shifting Problem

Recommended Posts

Hi LSers,

Has anyone experienced this problem, and if so what should I look for(?) transmission shifts ok while engine is not yet at normal operating temperature (about the second line up); once engine reaches normal operating temperature, shifting goes south - seems like it does not want to change in an orderly manner - O/D light begins blinking, etc. It seems like it is either in O/D, or in second (not sure which). I have to go manual into L from D to operate semi-normally.

I checked the MIL/CEL codes and get these: Check Engine - 71 (EGR I think); Transmission: 63 (Shift solenoid 2), 67 (O/D speed sensor). I have not done anything about any of these since I am not sure whether they are the culprits. I checked the shift solenoids prior to getting the Tranny rebuilt, and they operated normally outside the transmission; also all four solenoids resistances were within tolerance ranges (outside the tranny);

For the EGR - found that if I remove the EFI fuse and main engine relay, the CEL light goes out and remains off for several days before coming back on(?) So, not sure whether these two are related. Took the car to Toyota (No Lexus dealerships in town) and after keeping it for the whole day, they told me they were not sure, but it could be the TPS, the EGR modulator, the VSV(?), EGR valve; said it could be all, some, or some combination of these components. Any advice from experienced owners/listers would be very helpful indeed!

If I do have to change the speed sensor #2 or the O/D speed sensor, does anyone have a tutorial for this operation? I got under and could not find the darn things!

Thanks in Advance

Share this post


Link to post
Share on other sites

#63 is covered by the tranny pan which will need to be removed

#67 is on the outside of the tranny on the drivers side near the front

For the EGR I would look at removing it for a good cleaning, check for leaks / replace the vac hoses

Share this post


Link to post
Share on other sites

93ls400walt,

Thank you for the reply. I have not had a chance to check these out yet, but will. Do you think the EGR pipe leaking may have anything to do with this shifting problem? I mean, the shifting appears to be fine until the engine warms up to what appears to be normal operating temp, and only then I begin having problems with shifter!(?)

Thx

Share this post


Link to post
Share on other sites

I've not had any probs. with the EGR pipe. But have read others who have posted. Most have said the issue was the smell and noise.

One thought is that the oil would be a bit thinner when the engine is hot. And may more easily pass by any worn valves or seals. Thus not shifting properly????

Share this post


Link to post
Share on other sites

93ls400walt,

Shouldn't be the seals or valves - I just had the tranny rebuilt by a Toyota recommended indie(?) They did, however, put in Dxron III, in spite of my requesting they use only Type IV Fluid. Anyway, everything seemed fine for the first few months. However, now, while the engine is still under normal operating temp, the shifting is fine, then at normal operating temps, the shifting goes south. Seems like after it goes from first into third or O/D - just drags butt(?) I find I have to drop it down into L to begin moving faster. Could this be related to the solenoids, and speed sensor?

Thx

Share this post


Link to post
Share on other sites

The code 63, #2 solenoid malfunction, will most certainly require replacement of the #2 solenoid and is a reasonably common failure as the cars age. It is a quite simple job...removing the pan takes the most time. Sometimes, a solvent soak can free up a less than enthusiastic solenoid and has worked for me for quite a while now. I also recommend sticking with OEM for this part. See my post, #29 in the below link.

The code 71 (EGR System Malfunction) troubleshooting takes up 8 pages in the Factory Service Manual. Common issues are a stuck EGR valve (not too common), leaking hoses (or the EGR pipe) in the EGR system, or a non-responsive EGR temperature sensor. I cannot believe that a Toyota dealer would not be able to properly diagnose this, as it only requires a multimeter and a hand-held vacuum pump to diagnose almost any Toyota / Lexus EGR system.

http://www.clublexus.com/forums/ls400-foru...-problem-2.html

Share this post


Link to post
Share on other sites
93ls400walt,

Shouldn't be the seals or valves - I just had the tranny rebuilt by a Toyota recommended indie(?) They did, however, put in Dxron III, in spite of my requesting they use only Type IV Fluid. Anyway, everything seemed fine for the first few months. However, now, while the engine is still under normal operating temp, the shifting is fine, then at normal operating temps, the shifting goes south. Seems like after it goes from first into third or O/D - just drags butt(?) I find I have to drop it down into L to begin moving faster. Could this be related to the solenoids, and speed sensor?

Thx

I would put my money on the dxron three as being the culpret. read around and youll see these cars need Toyota type 4 tranny fluid. It most likley destroyed your tranny again, and if the people that put it in really are toyota recommended you should go complain and herass them until they rebuild it again and use the right fluid. Sorry the news isn't better.

Share this post


Link to post
Share on other sites

killerFatty & jeffls400,

Thx for the info. I had taken the '92 to Toyota and even they said they would be using D-III, so I was very surprised. Will try the solenoid/fluid change route before fussing with the idie again. Biggest problem I had with the tranny pan was getting it back up there with the sealant intact!

BTW, do either of you know how difficult it would be to replace the solenoid wiring harness - the four connectors inside the tranny, with the lead that connects to the ECM outside? I broke the connectors while taking out the solenoid to check, and rigged a plastic tie to hold them onto the solenoids. Now I have the correct replacement solenoid connector harness but need to know whether this is doable without dropping the entire tranny!

Thx

:o

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
Sign in to follow this