'00 LS400 Cruise control

[Moe47]

Hi guys. My 2000 LS400 was at the mechanic's and after picking it up yesterday, I noticed the cruise control just lets the car get faster and faster when going downhill. I could swear it used to keep the car at the set speed no matter if i was going uphill or down. 

 

Also just noticed I am getting a taillamp failure error, which i'm guessing is caused by a faulty third brake light as it wont light up. 

Am i going crazy? Was the LS400 never capable of slowing the vehicle when going downhill?

[1990LS400]

Yes, you are crazy!  The cruise control on the 2000 LS400 I drove for over ten years sure didn't slow the car down when going down hill.  Hybrid and all electric vehicles, however, do keep the set speed when going down hill by using regenerative braking to charge the traction battery. 

Maybe you are confusing your LS400 with your hybrid LS600hL.

[Moe47]

Thanks for the quick reply mate. I've just come back from a drive and I got to test it again on a hilly road. The car does maintain speed somehow. I don't know how it does it, but the rpm went down and the car stayed at set speed (75 mph) in a descent. Tested this over a 100 mile stretch and it was consistent.

Although I have to say the ascents/descents weren't extreme. The earlier drive where the car just kept going faster downhill was a much steeper road and in the city limits so the speed was set at 45 mph. 

Could it be that even going downhill the car can not speed up past a certain point considering the steepness on the motorway I was travelling on and was just coasting? I don't know anything about this technology AND bad at physics. 😂

[Exhaustgases]

The control will back off the gas going down hill but if the hill is real steep it will over come the engines ability to hold back the cars speed. LS cruise control at least on the Gen 1's does not control the brake system, maybe on the newer stuff its different I don't know. It would have been easy for them to tie it into the ABS system kind of like the Trac system is. And Lexus could have done that on the very first car in the Lexus line up. It would have been nice. And actually it is likely all in place in a Trac system car to do it with just a software modification. Too bad they don't release software info for the old stuff, its so old school why would they give a rats _____.

With a gen 1 to incorporate the cruise control into the ABS, the Cruise control ECU would have to be able to communicate with the ABS ECU, and unlike most all the now modern cars that have intercommunication with all control modules, the old Gen's did not have that. The older Gens though have the ABS and Engine ECU in communication with each other at least on the Trac systems cars.

[1990LS400]

OK, "Mate".  Exactly what does "Location: Other" mean.  If it is Australia or New Zealand and especially if your 2000 Lexus LS400 is really a Japanese market 2000 Toyota Celsior then all bets are off.  Does your car have "radar" (the term "radar" was used but it was really "laser") cruise control?  If it does, it does not work like the cruise control on the 2000 LS400 that was sold in the U.S. and Canada.  This is a Lexus forum for North America.

 

[Moe47]

@Exhaustgases That makes sense. The accuracy with which it maintained the set speed throughout the stretch had me fooled. I will have to start being more careful driving close to speed limits on CC.

@1990LS400 Mixing with the Brits has rubbed off on me, innit bruv. But no, the car is a 100% Lexus LS400 year 2000 from North Carolina that I personally shipped to the UAE. Like I said, I got goofed into thinking the car was braking/downshifting to maintain speed downhill. Cheers!

[M.Yasir]

Welcome to the forum Moe, and enjoy your lexus

As far as i can report on this, my 1998 Lexus does maintain the same speed when going down hill but not 100% accurate, it may slip but not that much, showing 99.9 MPG

On 5/7/2016 at 6:38 AM, Moe47 said:

@Exhaustgases That makes sense. The accuracy with which it maintained the set speed throughout the stretch had me fooled. I will have to start being more careful driving close to speed limits on CC.

@1990LS400 Mixing with the Brits has rubbed off on me, innit bruv. But no, the car is a 100% Lexus LS400 year 2000 from North Carolina that I personally shipped to the UAE. Like I said, I got goofed into thinking the car was braking/downshifting to maintain speed downhill. Cheers!

UAE? we are in the same place then... were you trying your cruise when coming down from Jabal Hafeet?(It is a mountain top)

[Moe47]

On May 15, 2016 at 2:57 PM, M.Yasir said:

Welcome to the forum Moe, and enjoy your lexus

As far as i can report on this, my 1998 Lexus does maintain the same speed when going down hill but not 100% accurate, it may slip but not that much, showing 99.9 MPG

UAE? we are in the same place then... were you trying your cruise when coming down from Jabal Hafeet?(It is a mountain top)

Hello @M.Yasir. Thanks.

Our Lexuses do not slow down, I'm afraid. I tested this quite a few times since my last post. A quick test is to find a steep road and set cruise at a low speed. They can only decelerate. 😔

We are in the same place indeed. No, this was at the small hills on the way to Fujairah from Abu Dhabi/Dubai, just before reaching the city.

 

[M.Yasir]

Moe did you happen to find a good repair garage for lexus here?

[M.Yasir]

Moe did you happen to find a good repair garage for lexus here?

[Moe47]

There's one in Musaffah that a few of my colleagues and friends swear by, but I haven't had the chance to go there. I could get you the contact details if you require. I'd like to hear if you've found any reliable garage too. 😅

I am in Fujairah in the weekends so I sought out a mech there. Very reasonable, honest and knows what he's doing, so I'm content.

Edit: Forgot to thank @Exhaustgases and @1990LS400. Thanks for your input guys, you were right. And @M.Yasir. Be careful don't trust the cruise. 😂

[M.Yasir]

As far as i can remember, when i was traveling to Fujairah, the cruise was able to control the speed, i was not using accelerator there, but yes you are right it does not applies brake just like Audi's Hill Assist function.... maybe i got carried away by seeing my current mileage which was 99.9 all the time so i did not notice...

You can browse through my thread

 At random i went to this garage (to be honest my car broke down near to this guy so had no choice, Launch Auto garage, Al Quoz Industrial, Dubai), mechanics here are not bad, the garage manager tried to loot me by replacing the starter motor with a new one (1350 dhs) and also a new battery.. but i went to sharjah and bought a used one for 200 dhs and of course with so much help from this forum and the experts here, i got lucky.. labor charge is also minimal, i paid 500 dhs for the whole job

I heard Rose garage in Mussaffah is good but they are too slow.. and labor charges are expensive..

By the way how many miles you have on your car?

[Moe47]

Thanks for the info on the garage, I'll make a note of them. Honest mechanics are hard to find. Especially so in this country as the people have set bad precedents.

I did happen to read that thread as I was lurking the forums. Useful info. What's the deal with the 99.9 mileage though?

My car has done 236,000 miles! It's an old beast. But runs smooth, hope nothing major to work on pops up. Forgot to post a picture, so here goes.

There's a few problems with the car I haven't gotten around to fix, but will leave that for another day.

[M.Yasir]

That's a nice one, what about the interiors?

[Moe47]

Thanks. She's got a couple dents, small scratches here and there, but I'll survive. Haven't had the chance to take pictures of the interior after I changed the stereo unit. Will do that and post later. The leather isn't beige though. 😔

[Moe47]

Here's a few unimaginative pics of the inside. Although gloomy, the interiors are in decent condition. As mentioned earlier, the mileage clock display won't light up. Apart from that, front AC vent clips missing, steering wheel worn, a little bit of leather wear on the outside of the driver's seat.

[sha4000]

No seat heaters? I guess you don't need them where your located.

[M.Yasir]

Is it with full options Moe?

[Moe47]

Craig, No seat heaters. Previous owner must have been a cool cat. But then again, N. Carolina doesn't know what winter is. And you're right about not needing that feature here. Could do away with seats altogether for bags of ice in their place.

Mohammed, I wouldn't know what a full options variant on these would be. Mine didn't come with Nak, or a nav system. Has/had the Premium sound system, auto dimming mirrors, auto-leveling HID lights etc. So I'm guessing it's not close to a full option. 😅

[M.Yasir]

Well even i cannot say with full confidence what might be the full options... since these cars came to US only maybe other experts here would tell what includes in the full options/option 1

You changed the music system... hmmm with what make? are you able to make use of the amp already provided?

Auto levelling HID? did LS400 came with HID from the factory? i just wonder... mine is from west virginia and have normal bulbs in the headlight, sun roof, leather seats and massage seats

[sha4000]

HID bulb were an option in the 98 model I believe. 

[Moe47]

Mohammed, I did change the headunit to a Pioneer AVH-8750BT. Loving the Apple Carplay on it, although Apple maps doesn't support navigation in the UAE yet. Replaced the factory amp with a spare one I had lying around. Due to this, the sub isn't connected anymore but it was partially blown anyway. Planning to get a mono block and fix a subwoofer soon. Hopefully a free air 8 incher so I can have it fitted in the factory sub's place. I need every inch of that trunk space!

I was half inclined to order the beatsonic harness and use the factory amp but decided against it. Will definitely do that for my next LS. Feels so good to be able to play music through USB, though. I'm gold if Apple fixes its maps.

Oh what I wouldn't give for massage seats!

[M.Yasir]

hmmm i heard kenwood ddx470 is a good direct replacement in LS400 which connects the amp and the sub... only downside will be the original look of the car will be gone but on the other hand it is always nice to have a good LCD display...

[Moe47]

I remember reading about it somewhere on here too. But then I think it was a Nakamichi. Don't know how different it would be for a non Nak. Personally, I don't mind the splicing. And yeah, it really is convenient to have a more modern music system and do away with the cassette-aux/aux-in annoyance. Plus, what I like with this pioneer is how phone integrates seamlessly using the CarPlay feature and that it even supports my FLAC music collection. I don't have to go through the trouble of compressing them into a lossy format.

[M.Yasir]

are you serious it can play FLAC? brilliant