johnstonls430 Posted August 31, 2006 Share Posted August 31, 2006 Please help help!! I've got a 2001 LS430 that, while driving [with the a/c on and in auto] at any speed, will just shut off for no apparent reason--you never know when it will 'strike'. I mean everything shuts down immediately--like you never put the key in. I've had several lexus mechanics attempt to diagnose and duplicate without success. Throttle body cleaned and replaced, throttle gasket replaced, etc etc. Once the vehicle stops and sits for a moment...it starts back up and runs normally. Any ideas?? Nothing is more dangerous that traveling at highway or surface street speeds and you lose everything...left lanes are a thing of the past for me. I really appreciate any help here. Quote Link to comment Share on other sites More sharing options...
dcfish Posted August 31, 2006 Share Posted August 31, 2006 Please help help!! I've got a 2000 LS430 that, while driving [with the a/c on and in auto] at any speed, will just shut off for no apparent reason--you never know when it will 'strike'. I mean everything shuts down immediately--like you never put the key in. I've had several lexus mechanics attempt to diagnose and duplicate without success. Throttle body cleaned and replaced, throttle gasket replaced, etc etc. Once the vehicle stops and sits for a moment...it starts back up and runs normally. Any ideas?? Nothing is more dangerous that traveling at highway or surface street speeds and you lose everything...left lanes are a thing of the past for me. I really appreciate any help here. It sounds like it could be something in the ecu that expands and disconnects, Then cools down and reconnects like a crack in a circuit board or something on those lines. Just a guess, I had a car back in the 80's that did this and it reminds me of my few times going down the road then WHAM totally off, disconnected, shutdown. 5 min. later it would start and I never knew when it would happen again. Quote Link to comment Share on other sites More sharing options...
nc211 Posted August 31, 2006 Share Posted August 31, 2006 Please help help!! I've got a 2000 LS430 that, while driving [with the a/c on and in auto] at any speed, will just shut off for no apparent reason--you never know when it will 'strike'. I mean everything shuts down immediately--like you never put the key in. I've had several lexus mechanics attempt to diagnose and duplicate without success. Throttle body cleaned and replaced, throttle gasket replaced, etc etc. Once the vehicle stops and sits for a moment...it starts back up and runs normally. Any ideas?? Nothing is more dangerous that traveling at highway or surface street speeds and you lose everything...left lanes are a thing of the past for me. I really appreciate any help here. It sounds like it could be something in the ecu that expands and disconnects, Then cools down and reconnects like a crack in a circuit board or something on those lines. Just a guess, I had a car back in the 80's that did this and it reminds me of my few times going down the road then WHAM totally off, disconnected, shutdown. 5 min. later it would start and I never knew when it would happen again. I agree, it sounds like it's the ecu unit. I'm SUPRISED the lexus dealership didn't check that, but instead spent their time on the throttle body. You say it only happens with the A/C unit on??? I wonder if the alternator is bad. The a/c electrical pull could be too much for the alternator, which kills the car. Maybe the battery is strong enough to restart the car, but once the alternator gets loaded down, it kills it again.... Quote Link to comment Share on other sites More sharing options...
dcfish Posted August 31, 2006 Share Posted August 31, 2006 Please help help!! I've got a 2000 LS430 that, while driving [with the a/c on and in auto] at any speed, will just shut off for no apparent reason--you never know when it will 'strike'. I mean everything shuts down immediately--like you never put the key in. I've had several lexus mechanics attempt to diagnose and duplicate without success. Throttle body cleaned and replaced, throttle gasket replaced, etc etc. Once the vehicle stops and sits for a moment...it starts back up and runs normally. Any ideas?? Nothing is more dangerous that traveling at highway or surface street speeds and you lose everything...left lanes are a thing of the past for me. I really appreciate any help here. When it dies and you turn the key to the acc. position does the dash light up ? Quote Link to comment Share on other sites More sharing options...
SRK Posted August 31, 2006 Share Posted August 31, 2006 That's a very common symptom of the kinds of cars I used to work on. An engine stall that occurs above idle, and allows a restart within minutes, with no running problems before or after the event, is usually a main power relay or fuel pump relay. The relay trips out, and resets as the engine is re-started. Change the pump relay. Cheap. Quote Link to comment Share on other sites More sharing options...
SW03ES Posted August 31, 2006 Share Posted August 31, 2006 Thats definatedly bizarre, sorry I can't be of any advice. There is no such beast as a 2000 LS430 though. The 2000 was an LS400, the first LS430 came out for 2001. Quote Link to comment Share on other sites More sharing options...
sha4000 Posted August 31, 2006 Share Posted August 31, 2006 i was wondering when someone was going to correct him, i cant believe the dealership couldnt find the problem and instead used guest work Quote Link to comment Share on other sites More sharing options...
1990LS400 Posted August 31, 2006 Share Posted August 31, 2006 As I mentioned in past posts, a similar problem occured every 3-4 1/2 years on two different LS400's. I always took the car directly to the shop and each time the problem was a broken connection between battery cells -- the connection would break and reconnect when hitting a bump or turning a corner and the problem was intermittent. A new battery solved the problem every time. When it happened on my current 2000 LS400 in 2004 when the car and battery were almost exactly four years old, I simply took the car in for a new battery and didn't even bother to have the battery tested. I don't remember if the A/C was on or not but I almost never turn it off so it was probably on. The problem always happened spring, summer or fall and never in the winter. The repair shop owner (Ben Bennett, Exact Performance, Shawnee KS) - a former Lexus dealer service writer - told me that this is a common problem on the LS series. Of course it could be something else but this problem has happened at least four times to me and a new battery always solved the problem. I've got a reminder on my PDA for a day in 2008 -- when the reminder alarm goes off I will drive directly to the shop to get a new battery. Quote Link to comment Share on other sites More sharing options...
RFeldes Posted August 31, 2006 Share Posted August 31, 2006 I have to agree with 1990ls400....Battery! First thing I would replace. As for a 2000 ls430..It could be an 01 built at the end of 2000 when they came out. Quote Link to comment Share on other sites More sharing options...
SW03ES Posted August 31, 2006 Share Posted August 31, 2006 As for a 2000 ls430..It could be an 01 built at the end of 2000 when they came out. But even if it were built in 2000, its still a 2001 LS430 or a 2000 LS400. As to the battery issue, thats odd I'd never heard of that before. Quote Link to comment Share on other sites More sharing options...
SRK Posted September 1, 2006 Share Posted September 1, 2006 . As to the battery issue, thats odd I'd never heard of that before. I agree - I have replaced a lot of batteries in customer cars over the years, and only once have I seen a cell disconnect from the others, and that battery failed completely in less than 30 minutes. To have four seems a bit unlikely - change brands for sure eh? Quote Link to comment Share on other sites More sharing options...
SW03ES Posted September 1, 2006 Share Posted September 1, 2006 Yeah, my dad had his 98 for 6 years 160k miles and never had that happen, he's had his 04 for 3 now and never has had that happen... Quote Link to comment Share on other sites More sharing options...
1990LS400 Posted September 1, 2006 Share Posted September 1, 2006 . As to the battery issue, thats odd I'd never heard of that before. I agree - I have replaced a lot of batteries in customer cars over the years, and only once have I seen a cell disconnect from the others, and that battery failed completely in less than 30 minutes. To have four seems a bit unlikely - change brands for sure eh? Two of the batteries that failed were the OEM batteries that were installed at the factory or when the two new LS400's were unloaded from the boat - whenever the OEM battery gets installed. At least one of the other batteries that failed was an "Interstate". I have provided this same information on this and several other Lexus forums over the years and have have seen that several other LS owners have replied and said that replacing the battery resolved the problem. But of course the cause of the problem could be something else. Quote Link to comment Share on other sites More sharing options...
SKperformance Posted September 1, 2006 Share Posted September 1, 2006 I am pretty well lost ,glad the year was mentioned as it was another oddity. Does as you say the car shuts down like you never put the key in leave the dash gauges on or does the car go dead that not even an interior light turns on? I can only think by your description to the dealer thy looked at the throttle body because it kept the systems going but the engine stopped. Please clarify. Quote Link to comment Share on other sites More sharing options...
SW03ES Posted September 1, 2006 Share Posted September 1, 2006 Weird... Quote Link to comment Share on other sites More sharing options...
johnstonls430 Posted September 1, 2006 Author Share Posted September 1, 2006 Thats definatedly bizarre, sorry I can't be of any advice. There is no such beast as a 2000 LS430 though. The 2000 was an LS400, the first LS430 came out for 2001. Thanks--had a syntax error on the year. I appreciate all the help. I am shocked a certified lexus tech AND a lexus rep cannot figure it out...or care for that matter. Please help help!! I've got a 2000 LS430 that, while driving [with the a/c on and in auto] at any speed, will just shut off for no apparent reason--you never know when it will 'strike'. I mean everything shuts down immediately--like you never put the key in. I've had several lexus mechanics attempt to diagnose and duplicate without success. Throttle body cleaned and replaced, throttle gasket replaced, etc etc. Once the vehicle stops and sits for a moment...it starts back up and runs normally. Any ideas?? Nothing is more dangerous that traveling at highway or surface street speeds and you lose everything...left lanes are a thing of the past for me. I really appreciate any help here. It sounds like it could be something in the ecu that expands and disconnects, Then cools down and reconnects like a crack in a circuit board or something on those lines. Just a guess, I had a car back in the 80's that did this and it reminds me of my few times going down the road then WHAM totally off, disconnected, shutdown. 5 min. later it would start and I never knew when it would happen again. I agree, it sounds like it's the ecu unit. I'm SUPRISED the lexus dealership didn't check that, but instead spent their time on the throttle body. You say it only happens with the A/C unit on??? I wonder if the alternator is bad. The a/c electrical pull could be too much for the alternator, which kills the car. Maybe the battery is strong enough to restart the car, but once the alternator gets loaded down, it kills it again.... I'm printing the last two and marching up to the dealership--this hasn't been approached. Thanks folks. Quote Link to comment Share on other sites More sharing options...
johnstonls430 Posted September 1, 2006 Author Share Posted September 1, 2006 I am pretty well lost ,glad the year was mentioned as it was another oddity. Does as you say the car shuts down like you never put the key in leave the dash gauges on or does the car go dead that not even an interior light turns on? I can only think by your description to the dealer thy looked at the throttle body because it kept the systems going but the engine stopped. Please clarify. - I did take a nose dive on the year--oops...i meant 2001 new body style but it was manuf in mid-2000. Anyway, that's right, nothing comes on or stays on. Yesterday, sitting at a light, A/C on as usual, briefly accelerated and then everything just shut down. No hesistation or anything. Just off. I turned the car off briefly, then back on and it started back up in [less than 2-4 minutes of wait time]. Quote Link to comment Share on other sites More sharing options...
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