1995 ls400 bumpy transmission
02-04-18, 03:41 PM
#16
At 170K there are plenty of rubber bushings that are commonly due for replacement. Engine mounts, transmission mount, rear differential carrier mounts. As well many threads about suspension bushing wear. For yours the whole driveline would be good to inspect for torn compressed bushings. Verifying the transmission fluid too. We suggest Toyota Type IV though if there has been a mix of incompatible fluids added, this may contribute to an issue.
The capacitor thread is one that links to many driving scenarios. Having the ECU inspected for leaking capacitors is one to rule out for odd driving conditions otherwise not explained.
The capacitor thread is one that links to many driving scenarios. Having the ECU inspected for leaking capacitors is one to rule out for odd driving conditions otherwise not explained.
● problems in getting into diagnostic mode or scanner says "no communication"
● random dropping into "limp home" mode
● weird shifting problems
● OBD port is unresponsive, seems dead
● throwing random fault codes
● engine won't rev out/rev limits at 2000 or less rpm
● engine runs like crap, then suddenly runs fine again
● random not starting or cutting out
● low idle or erratic idle
● often very hard to start, requires starting fluid
● transmission will not automatically shift, only manual shift is possible
● transmission jerks from 1st to 2nd gear, and kinda slips from 2nd to 3rd
● no A/C compressor operation
● idle speed rolling up and down, or sometimes too low and sometimes too high
● speedometer not working reliably
● speed (cruise) control not working
● tachometer not working sometimes
● air bag light flickering intermittently
● A/C going into reset with flashing front defog light (front defog light typically flashing 10 times)
● check engine light on sometimes, but no codes stored, often in concert with ECT light
● ECU not communicating with scanners or not displaying codes with jumper installed
● bad sulfur exhaust smell in concert with not running right above
● random dropping into "limp home" mode
● weird shifting problems
● OBD port is unresponsive, seems dead
● throwing random fault codes
● engine won't rev out/rev limits at 2000 or less rpm
● engine runs like crap, then suddenly runs fine again
● random not starting or cutting out
● low idle or erratic idle
● often very hard to start, requires starting fluid
● transmission will not automatically shift, only manual shift is possible
● transmission jerks from 1st to 2nd gear, and kinda slips from 2nd to 3rd
● no A/C compressor operation
● idle speed rolling up and down, or sometimes too low and sometimes too high
● speedometer not working reliably
● speed (cruise) control not working
● tachometer not working sometimes
● air bag light flickering intermittently
● A/C going into reset with flashing front defog light (front defog light typically flashing 10 times)
● check engine light on sometimes, but no codes stored, often in concert with ECT light
● ECU not communicating with scanners or not displaying codes with jumper installed
● bad sulfur exhaust smell in concert with not running right above
02-09-18, 11:08 PM
#18
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Bumping Transmission
1995 lexus ls400 has 170K miles. Runs good but transmission bumps when driving when I ease my foot on the accelerator. When I drive in 3rd gear locally or when using cruise control on highway, there is no problem with the bumping trans. In cruise I can use the speed lever to increase or decrease speed without the problem. When in cruise, if I use the accelerator to speed up to pass someone, as soon as I ease up on the gas pedal it bumps. So it seems to only do it when I ease up on the throttle. Doesn't happen in third gear. Could it be a software problem?
I had engine and transmission mounts replaced. Still have the same problem.
I had engine and transmission mounts replaced. Still have the same problem.
02-10-18, 04:15 AM
#19
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1995 lexus ls400 has 170K miles. Runs good but transmission bumps when driving when I ease my foot on the accelerator. When I drive in 3rd gear locally or when using cruise control on highway, there is no problem with the bumping trans. In cruise I can use the speed lever to increase or decrease speed without the problem. When in cruise, if I use the accelerator to speed up to pass someone, as soon as I ease up on the gas pedal it bumps. So it seems to only do it when I ease up on the throttle. Doesn't happen in third gear. Could it be a software problem?
I had engine and transmission mounts replaced. Still have the same problem.
I had engine and transmission mounts replaced. Still have the same problem.
Yours has a throttle- transmission cable while mine does not, so arguably my transmission is more dependent on thecTPS and pedal position sensor, but yours would probably respond well to replacement of TPS:: a two track/duel.resistive element mechanical device.
It is necessary to index and adjust new TPS.
Share your results .
Last edited by YODAONE; 02-10-18 at 04:19 AM.
02-10-18, 06:35 PM
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02-11-18, 12:41 PM
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02-13-18, 12:17 PM
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Although no engine codes displayed or detected on my 1999 LS400, replacing the throttle position sensor (TPS) improved transmission behavior on automatic downshift .
Yours has a throttle- transmission cable while mine does not, so arguably my transmission is more dependent on thecTPS and pedal position sensor, but yours would probably respond well to replacement of TPS:: a two track/duel.resistive element mechanical device.
It is necessary to index and adjust new TPS.
Share your results .
Yours has a throttle- transmission cable while mine does not, so arguably my transmission is more dependent on thecTPS and pedal position sensor, but yours would probably respond well to replacement of TPS:: a two track/duel.resistive element mechanical device.
It is necessary to index and adjust new TPS.
Share your results .
02-13-18, 12:54 PM
#27
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What to expect from a "Parts store"...
DO NOT buy aftermarket on this critical sensor...
Dealer pricing is reasonable and you get durable Denso part....buy new screws while there.
02-13-18, 01:02 PM
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My car is not a 1999. It is 1995. Does that make a difference?
02-13-18, 04:23 PM
#29
Lexus Champion
ok..Since recommending use of OEM Denso brand TPS sensor, .check with dealer on TPS for your vehicle...suggest you have your VIN # to be sure of proper selection.
Your TPS sensor(s) should have visible P.N.s on housing.
Some images to guide you..apparently two positioning sensors optioned with "TRAC"
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07-09-15 10:23 AM