martin01

I´m am a new owner from Sweden of a Lexus LS 400 -96 which has 25.000 miles on the odo.

I have two problems with my car: (my english isn´n so good but i hope you will understand the problems)

1. I have a heavy vibration at 1200 rpm the first 0-10 minutes when the engine is cold. It feels like the vibration comes from the transmission`or the engine. But I´m not sure. After about 10 minutes you can still feel a very small vibration at that rpm but not as much as when the engine is cold.

2. The car jerks a little bit at speeds over 40 mph. My dealer told me to change the ECU because there have been some problems with these for some LS 400 -96. Does anybody know if this is true?

Strida

Read NC211 post about his Transmission Stutters 95LS.

martin01

I talked to my Lexus dealer today. He have heard about this ECU-problem at three other LS 400 cars in Sweden! The problem is who is gonna pay for the replacement of the ECU!
Can it damage the car if I not replace the ECU?

Thank You
Martin

RA40

iTrader: (6)

Verify that function of the ignition and fuel system is okay. Things like a damaged ignition wire, carbon deposits on plugs or distributor caps, vacuum lines, air filter...any of these may be partial causes for an engine not running well.

Remove the air snorkel and air filter and check the the MAF sensor doesn't have debris or some oil accumulation. Often caused by a heavy oiling from washable air filters like K&N. Either way, check that it is not obstructed in some way.

Unplug the fuse to the EFI pooters for 30 seconds to 1 minute. This defaults the system to original programming.

Have the car plugged into a diagnostic pooter (dealer) to check for any error codes. Do you have a <check engine> light?

The O2 sensors.

Check the exhaust system for any signs of damage.

martin01

Thank you for your reply
I will check those things you wrote in your reply!

/Martin

martin01

I talked to my delaer today. He will replace my ECU for free .
I hope this will help! I let you know after the 9/7.

Wish me good luck!

NC211

Martin,
You will love the new ECU unit in your car, it will change the way the car shifts completely. I just had mine done on my 95' LS and wow, what a big difference! The gears shift so smoothly I can't feel it 99% of the time. The buckling is gone as well.

Good luck!

martin01

I have got my new ECU in the car now!. And YES, the gear shifts more smoothly now. But I still have the jerks when I drive idle speed at 40 mph and higher. I dont understand why the car is jerking. The jerks is gone when I put the A/C off. So, it I think it has something with the A/C to do. But there are not deafault-codes when my dealer make a diagnostic test. What shoud I do?
Please help!

Regards
Martin

NC211

Martin, my a/c will create a little "pull" when it's on too, but mostly when i'm sitting still at a light, not when I'm cruising. I'm not really sure what it could be? Did the dealer replace your ecu unit with an updated model or just with a refurbished model of the older one? It could be the throttle position sensor maybe? Did they change the spark plugs as well when they did the ecu unit? The TSB on the issue called for the plugs to be replaced as well.