ls400dfw

I have a clean 95 ls400 with 140k (put 8k on already) bought six months ago,for $3900. I have that darned throttle shock/jerk when pull off the gas pedal over 37 mph occurring at random times. The car has a great service history with paperwork and dealaership tune-up regular services. Timing belt, power steering, trans fluid changes, bushings, ect.. all replaced within the last few years. I'm starting with the ecu tsb replacement and most likely getting the tranny mount replaced from that straining from the torque converter clutch delay - defect in the ecu. This is very minor work, but is frightening to have such a weird problem on a nice reputable car. I hope the $100 ebay ecu gets to the source.

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From other posts:

LS400 DRIVABILITY IMPROVEMENT - To improve driving smoothness at speeds above 40 miles per hour, the following components have been changed.

Applies to all 1995 vehicles from JT8UF22E*S0O:

Old part / New part / Application
89661-50220 / 89661-50224 / ECM Fed. (veh prod 9410-9502)
89661-50221 / 89661-50224 / ECM Fed. (veh prod 9502-9507)
89661-50230 / 89661-50234 / ECM Cal. (veh prod 9410-9502)
89661-50231 / 89661-50234 / ECM Cal. (veh prod 9502-9507)
88240-50070 / 88240-50071 / Cruise Control Computer (veh prod 9410-9507)
90919-01180 / 90919-01178 / Spark Plugs (veh prod 9410-9507)

ls400dfw

The ecu 50224 is almost impossible to find at the moment. I found a place to reprogram it for $225, but I was arguing with the lady there that said" the programming is the same for 50221- 50220, 50334, 50335 - ect.. I was explaining to her the programming has to be different from my 89661-50220 due to the TSB and issues with that ecu. She still disagreed.

Thermactor

iTrader: (1)

see attached

JimsGX

YIKES Thermy!!!!

7schulz

The Lexus tech I talked to yesterday said the 50224 is no longer the number they are selling and it has been replaced with the 50220 again. Basically they made a full circle and sounds like they updated the 50220 with the correct (TSB corrected) program.

They also thought that a 50221-222-223-224-225 would also work. Couldn't tell me for sure but that was the part number sequence of supersession.
Does anyone know if this is true, I just placed an order at my local junk yard for 50221-2-3-4-or 5 since that was the supsecession sequence of part numbers for the 95.

If they have one it will be $143 includes shipping and tax and I found the CC for $30 on ebay.

ls400dfw

In my original post I accidentally put 334, 335 instead of 224, 225... I emailed the female the TSB, but "surprisingly," no response.
The lady previously sent me this, which furthers what 7schulz said regarding Lexus's ecu shenanigans..
But, I don't think this clears up your question, schultz. In the TSB it does list the 220, so if you get 220 it would 99% be the old version, since it's impossible to find a 224 at the least.

LEXUS LS400 95 Elec Cont Unit (ECU); (right side dash),

Ident: 8966150220 new
Ident: 896615022084 exchange
Ident: 8966150221 new
Ident: 896615022184 exchange
Ident: 8966150223 new
Ident: 8966150224 new
Ident: 8966150225 new
ECM (Elec Cont Module).

- So the ecm rebuilder/re-flashing people must use an updated code. I wanted to avoid the 50225 (last update?) and get a 50224, regarding results reported here on CL...After hours of calling via online, I somehow found a guy via ebay on the phone and heard him physically sorting through 200 ecm's and didn't find one 224 or 225.. It's like a rare diamond out there.
So, if I now go the rebuilt method, will I get a good ecm - (without 40+ mph rare throttle jerk when let completely off of the gas pedal ) - to replace my 50220 or 50221 on my car?

Thanks Toyota, at least this defect isn't quite as life threatening, but still could be dangerous.

ls400dfw

I called Lexus and politely asked them to recall this obviously defective, potentially dangerous ecm for all the 1995 Lexus Ls400's, and was politely declined.

Lexus Headquarters Phone: 800-255 3987
Fax:

19001 S. Western Ave. L203
Torrance, California, 90501
U.S.A.

7schulz

I have called them/emailed them 3 seperate/different time and filed a claim with there customer service office, to get them to resolve the issue and nothing, this last time I just asked them for the parts and I would pay for labor ie myslef installing it but I keep working the safety angle and that they have policy just for this kind of issue. Just give me the parts so I can drive my car sefely

7schulz

My throttle jerk is not rare it's everytime unless I am careful to feather it off which isn't always possible in traffic. This is definitly a safety issue it have lost control on an icy bridge bc. jerked hard enough to shif weight forward and slow the rear tires.

Is there anyone in the states that can build a new program so this doesn't happen and work in a performace tune when I switch it to power with the trans switch? Wouldn't that be great.

Thermactor

iTrader: (1)

When I put the updated $65 junkyard California ECU in the '95 Federal LS4, the jerkiness went away. I actually hated driving the car because of the throttle-off clunk. It was an easy fix. Just get an updated ECU and be done with it!
An interim "fix" might be to attach a vacuum hose to the blocked-off nipple on the front of the plenum to the pre-TB power steering idle-up attachment port on the black intake resonator. This will raise the idle by slightly bypassing the ISC.

7schulz

Thermactor,

Do you have a write up or a how to on changing the ECU I got my 50224 in the mail today and can see the old one in my glove box but don't know how to get to it. I would like to get it in tomorrow.

7schulz

Got mine done, first remove the lower kick pannel just a few clips holding it in just give it a tug in between the bottom of the glove box and the kick pannel. then there 2 nuts one below and to the far right near the door jam and the other behind a hidden passage in the glove box, and 4 clips holding the glove box in. After you remove the two nuts grab between the glove box and dash/cd changer and give it a tug. A few more nuts and bolts holding the ECU brackets on, I got the new ECU in and my cruise contorl comp is on the way, so for the $160 I spent on the 2 computers it is definitly worth it, and easy enough to do. Now I don't have to worry about that throttle jerk.

Thermactor

iTrader: (1)

Congratulations. It's well worth it. Makes the car driveable again.

ls400dfw

I ordered the 50234 and checked out my tranny mount. It's in great shape. I look forward to smooth cruisings, thanks Therm.

7schulz

Yes 100% better I drove it into work today and boy does she run well and no jerking at all. Before when I had the cruise engaged and hit the brake or cancel on the lever it had just a slight jerk but now its smooth sailing all around. A must to change if you have a 95 with this issue. I don't have the new cruise control computer in yet so if you are strapped for cash it doesn't seem like you have to change the CCC out but for 30 extra bucks I'm doing it anyway. Toyota thought it was important enough to change for this TSB so I'm doing it.