97 Ls400 Transmission Problems?

[david6101]

97 Coach edition LS400, 127,000 miles. A few days ago, check engine light came on briefly, now is off...the wife commented that it seemed a bit "abrupt" shifting into reverse from park-I tried it, noticed that it did seem a little bit more rough than usual, but, as it didn't seem to exhibit any problems while in drive, just asked her to keep driving and monitoring. Yesterday and today, it has started shifting rather "jerkily" between gears in drive, almost like a "double pump". Checked the fluid, and, while it's a little dirty, seemed to be at normal levels. Thought I would take it down to the mechanic who has worked on it for me ever since I have owned it (bought it used with 73K miles on it)-but before I do, wanted to check the collective wisdom of this group. Any thoughts? Does this ring a bell for anyone?

David Baker

Merritt Island, FL

[Leadfoot]

The best thing to do is get the fault diagnostic code from the onboard computer. I have a '92 and you simply turn on the ignition, then connect a wire with pin terminals between the TE1 and E1 terminals inside the diagnostic connector or TDCL. This is found near the hood release (TDCL stands for Toyota Diagnostic Computer Link at a guess and each terminal is labelled under the lid) and the fault code will be displayed as a series of flashes on the "check" engine light. It flashes two numbers, i.e. two flashes pause 5 flashes is code 25. Sequence starts at low numbers and works upwards then repeats.

If someone could confirm that the later models retained this functionality then we will help you once you report back the code (literally takes 3 minutes to get them!)

Good luck.

[david6101]

OK...new info. Took the car to a highly recommended local transmission shop. By the way, the car is NOT currently exhibiting any shifting problems at all...this morning, everything seemed fine.(??!!) He drove the car, did not find any issues (of course), and they did a routing service...pulled the pan, etc. The fluid was somewhat dark and burned smelling, but there were no metal shavings to speak of in the pan. The fluid was last changed around 106K miles (24K miles ago) and 2 years. His recommendation was to NOT flush the tranny, but to simply replace the fluid that was lost when the pan was pulled, and button it back up. His reasoning was that because of the highly detergent nature of new fluid, it's possible that something could be dislodged, etc, and cause the transmission to actually stop working. Has anyone else ever heard that theory? I asked a couple of my car buddies, and they concurred.

Any thoughts on this? I wonder why the fluid was burned in the first place, etc...

[blake918]

Did the shop pull the code from the cel the other day when it was acting up (I know some years will store the code.)? I've heard mixed things on flushes, so I just drain my pan every 5k-10k miles, and I've done it enough to have gotten most if not all the old fluid out of the tranny. The fluid that's in there now could just be old. I'd start with regular tranny fluid changes since tranny failures are very rare on LSs, and see where that takes you. There are also some shift solenoids that are above the tranny filter that might be worth cleaning. ;)

[monarch]

The fluid was last changed around 106K miles (24K miles ago) and 2 years. I wonder why the fluid was burned in the first place, etc...

Maybe at 106K miles the independent shop installed American car transmission fluid instead of Toyota Type T-IV fluid.

[david6101]

OK...additional info. First of all, the check engine light has now come on and stays on...also, it seems to (intermittently) be "lugging" the engine down when coming to a stop-in other words, similar to a manual transmission car if you're in a higher gear, and come to a stop without engaging the clutch. The car can be driven, and seems to shift normally up through the gears-it's just that you have to shift it into neutral as you're coming to a stop. It then will accelerate normally, etc. Also, this behaviour is still intermittent-it's currently in the shop, and , when my mechanic drove it, it did not exhibit this behaviour.

He put a scanner on the test connector. Here's what the code said:

"1997-98 Automatic Transmissions Toyota A-340 Series Electronic Controls

Circuit Description

ECT ECU uses signals from throttle position sensor, airflow meter and crankshaft position sensor to monitor engagegment of Torque Coverter Clutch (TCC). ECT ECU compares engagement condition of TCC with lock-up schedule in memory to detect mechanical trouble of lock-up solenoid, valve body and torque converter. DTC is set when TCC lock-up does not occur during appropriate speed, or lock-up does not release at appropriate speed. Possible causes are:

Lock-up solenoid is stuck open or closed

Valve body clogged or valve stuck

TCC malfunction"

Based on this, I have authorized him to check the aforementioned solenoid, which I guess, has to be done by dropping the pan-does the valve body have to come out, or any other hard to do stuff? Any other thoughts?

Now here is some other info, which I am just now finding out from my wife.

She was in Jacksonville FL three weeks ago, while I was out of town (of course), and locked her keys in the trunk. After the local Pop-A-Lockl came out, he told her that he couldn't touch it, and it would have to be dealt with by the local Lexus dealer. It was at night, and apparently there were very few tow trucks available, for some reason. When she talked to me on the phone, I told her to make sure and insist on a flatbed "rollback" type of wrecker. When the wrecker arrived (after she had waited two hours!!), he already had a car on the flatbed, but insisted to her that it wouldn't be a problem to tow the car on a hook.

NOW GET THIS...he told her that he had 28 years of experience, and that it wouldn't be a problem because it was a FRONT WHEEL DRIVE car- he would just put it in neutral, and tow it with the hook in front, and the rear wheels rolling. Not sure exactly how far it was to the Lexus dealer, but she got it back the next morning from them, after they opened the trunk at no charge.

All the transmission problems seem to have happened since this. I can't swear that nothing was wrong before (after all, it's my wife's car, and she is not the world's best in letting me know about car problems), but I thought I would put this out there for your collective wisdom to think about.

David Baker

Merritt Island, FL

[monarch]

In your owners manual it says do not tow with the rear wheels on the ground faster than 30 MPH or for a distance greater than 50 miles or else transmission could be damaged. 127,000 miles is very, very early for electronic shift control solenoid or torque converter clutch problems on the rugged 340 series transmission so my guess is either the transmission was filled with the wrong fluid at 106,000 miles (e.g. a fluid other than Toyota Type T-IV fluid) or the transmission was damaged by the towing.

[Leadfoot]

OK...additional info. NOW GET THIS...he told her that he had 28 years of experience, and that it wouldn't be a problem because it was a FRONT WHEEL DRIVE car- he would just put it in neutral, and tow it with the hook in front, and the rear wheels rolling. Not sure exactly how far it was to the Lexus dealer, but she got it back the next morning from them, after they opened the trunk at no charge.

All the transmission problems seem to have happened since this. I can't swear that nothing was wrong before (after all, it's my wife's car, and she is not the world's best in letting me know about car problems), but I thought I would put this out there for your collective wisdom to think about.

David, I am very sorry to say if it looks like a duck, walks like a duck and sounds like a duck chances are, its a duck. Unfortunately the transmission will most likely have been damaged by the towing if you are observing the failures in the TCC or lock up.

[backwoods lex]

You should go after the towing company. The repair should come out of their pocket, not yours.

[david6101]

Update...replaced TC clutch lockup solenoid, replaced the fluid lost by lowering the pan, etc, and car seems (so far) to run fine...no shuddering, slipping, or otherwise funky shifting. So-looks like that was the problem.

Just another data point for the collective wisdom...

[monarch]

Yep, seems like 90% percent of the time the cause of shifting wierdness is a failed shift solenoid. The odometer mileage when solenoid failures occur seems to vary greatly from as low as 125,000 miles to 300,000 or more.