wbrian63

I thought I'd update the forum on a problem I discovered with my new-to-me 2007 LS460L, and the solution for the problem, courtesy of Technical Service Bulletin (TSB) TC009-07. The Canadian market TSB # is CAN-TSB2453L.

This issue apparently only affects 2007 460 and 460L models, and not even all of them. The VIN cutoffs are JTHBL46F*75046335 for the 460 and JTHGL46F*75019253 for the 460L.

Here is the issue and how to know if your car has the same problem. Get a cup of your favorite beverage - I'm a "wordy writer"...

After braking to a complete stop and remaining motionless for about 3-5 seconds, I could feel the car "shift" a bit (like if you had your left foot on the brake and your foot on the accelerator just a bit, then released the accelerator - the car doesn't physically move, but the suspension "shifts" in response to the reduced load). In an enclosed space, like my garage, I could also hear a pitch change in the standard hydraulic "whine" that comes from the automatic transmission. If you watched carefully, the tach would also move just a fraction up, then back down to its normal 700rpm spot.

When you release the brake pedal, rather than starting to smoothly roll away, you would feel a slight bump or nudge like the transmission was sliding into gear. Similar feel would be had in a manual transmission car if you let out on the clutch enough to start rolling, then fully released the clutch.

The first time I encountered the problem was my first day with the car in the parking garage at work. While rolling slowly into my regular parking spot (up against a wall, next to a column), I was paying close attention to the parking sensors, when the car stopped rolling. I was moving very slowly - really only creeping as I hadn't gotten used to the various warning tones and indicators to know when to stop. My first thought was that I'd inadvertenly kissed the wall with the front bumper.

I still had 3 bars on the parking sensor, but I got out to check my position in the space relative to the wall and I was still 3 feet away.

I thought it was just my imagination - the brakes on the car are very sensitive and maybe I had actually pressed just a tad more on the pedal while creeping into the spot. I dismissed the event as part of the learning curve with a new-to-me vehicle.

However, it happened again that night while pulling into the garage at home. I thought maybe there was a problem and the transmission was actually slipping into neutral, but when I moved the shifter to neutral, there was the expected chassis shift and audible changes one would expect.

The problem with this behavior is that when the transmission goes into what I'll call "half neutral", if you are just creeping along, the car will stop. When you release the brake to start rolling again, the acceleration is not linear - it is slow at first, but within a second, it increases as the transmission fully engages. This could result in a driver making unintended contact with a stationary object while making close quarter manuvers.

The longer I had the car the more irritating it became. In situations where I needed to make a quick off-the-line getaway, the car would noticeably jerk as the transmission moved from "half neutral" to fully engaged with my foot hard on the throttle. Just like if it was a manual transmission and I wasn't smoothly releasing the clutch.

What I also noticed was that if I let off the brake and allowed the transmission to re-engage, when I stopped a second time (like creeping in line at a drive-thru, or in heavy traffic), so long as I didn't touch the accelerator, the problem would not repeat itself the next time I took my foot off the brake.

The problem wasn't isolated by selecting 1st gear manually, nor was it removed by putting the transmission in Winter mode.

I proved that it was something unique to my car by returning to the dealership where I purchased the car and finding another 2007 460L for a thorough test drive. That car didn't have the issue at all. (In hind-sight, I got lucky with this test, as i could have potentially found a car older than mine that still had the old TCM software)

The TSB indicates that the new calibration number that has the fix for this issue is 895365001300. I used TechStream to verify that my car had calibration 895365001200.

Took the car to Lexus of Clear Lake, south of Houston, armed with the TSB information. As noted above, the VIN cutoff for 460L's is 75019253. My VIN ends with 75018243, 1,010 units before the cutoff.

I pre-arranged the visit with my service writer, and he made sure their top diagnostician was available to ride with me. The behavior is subtle, and it is most noticeable with only the driver in the car - extra weight from more passengers tends to dampen the feel of the re-engagement when you release the brake. We rode around in the lot at the dealership for about 20 minutes. He said he thought he felt it once or twice, but wasn't sure. I told him that in a quiet environment, he'd be able to hear the change in the tone of the transmission, but at a dealership adjacent to a major interstate, quiet is something that is in short supply.

The did a checkout of the car and verified that new software was available.

They charged me $125.00 to reflash the TCM with the new software - problem solved.

Apologies for the long post - but maybe this will help another CL member.

I am pretty sure that this behavior doesn't cause damage to the car - I've got 88,000 miles on mine and everything seems to be working just fine...

nightofday

Thank you for the lengthy post! I have this exact same issue and will head to the dealership armed with this info! Again, thank you for the detailed write up and fix!

Soldier76

Thanks a ton. I believe I'm experiencing the same issue with my car, but will test it again to make sure.