LX 570 randomly dies while driving (1 Viewer)

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Yesterday evening while driving on the highway at about 70 mph, my LX suddenly died. Lights turned off, dash goes dark and the engine stopped for a second or two. While still moving, the car started again everything came back on and driving continued as normal. About 30 minutes later, the same thing happened again. No warnings came on after either of these two instances. I have a blue driver scan tool and no codes were thrown either. The vehicle had over 1/2 a tank of gas and has a newer odyssey group 31 battery. It was not raining, and the weather was about 70 F out. Beyond some BFG KO2 tires and upgraded battery, the vehicle is completely stock.

I found some similar issues in threads on here, but it seems like most cases the vehicle remained off until the driver pulled over and started it again. I have spoken with a few Lexus service departments but none of them had ever seen an issue like this before. Wanted to check here and see if anyone has experienced something similar.
 

radman

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It started again on its own??

If you're in Drive, the starter won't initiate unless you shift to P or Neutral.
 
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Agreed. Symptoms sound battery related. Sounds like you're losing all power.

Most likely issue is a battery connection. Connection to the terminals. Or ground strap from the battery to the chassis.

Start with the battery terminals. Even if they seem connected, worth taking them off and check to see if the connection is secure. Clean any residue or corrosion.
 

CharlieS

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Sounds a little like when my fuel pump ECU died. That was a fun one to troubleshoot...
 
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While plausible, I don't believe the dash will go dark in a situation where the fuel pump stops.

Is the Odyssey batt you have a center post setup? Are you using a Slee kit? Those have been known to cause connection/corrosion/heat cycling issues due to the extension being made of aluminum. You can clean and re-secure the connections but it will rear its ugly head again.
 

radman

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whether it's battery or fuel, the starter isn't allowed to crank (under normal conditions) if the transmission is in D.

Unless it's fuel.... and everything seems like it's dying/starving.... knock sensors subdue the engine to make it seem like it's dead.... and then fuel pump kicks back in and engine revives without the starter.

ok, i just convinced myself that it's a fuel issue.
 
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I've never seen a fuel pump cause the dash to go dark - maybe light up like a xmas tree but not dark.

"Lights turned off, dash goes dark and the engine stopped for a second or two. "
 
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Thanks for the replies everyone, this is definitely a weird issue. It seems like it would be electrical related since the dash went dark and the lights shut off for a second. I'll try to dig further into that area tomorrow. I am running the Slee kit for the group 31 battery and it has standard posts. I drove around a bit today and everything seemed normal again. I would think if it is fuel pump related I would get some sort of code but who knows. I might bring it into the dealer and have them take a look at the fuel pump/ fuel pump ECU since I'm still covered under the extended warranty for 3k miles.

When the vehicle died and then started again, it almost felt like I was in a manual transmission car coasting down the hill and then popped the clutch to get it started. Very weird...
 

FrazzledHunter

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I know how you feel. It can be terrifying to have your vehicle just go dead unpredictably.
All you can think about is stuff like "Well is it going to die in this tunnel? On this bridge? On this highway with no shoulder?"
Once it does that you can't relax. Driving becomes a nightmare.

Had any service work done on it like a timing belt, water pump, alternator etc?
This is what an excellent mechanic asked me when I finally found a place that fixed my 100 series LC that did almost the same thing.
It's not that I think a bad timing belt would be causing your symptoms like the dash going dark. What I'm suggesting is that you might have an issue due to service work damaging or bumping a wiring harness loose. And it wouldn't have to be recent either.

So how could replacing a timing belt and water pump result in the car dying suddenly and unpredictably?

What happened to me on my 100 series was that the metal shroud at the base of the fan slowly wore through the wiring harness to the crank sensor 2 years after the replacement of a timing belt & water pump. It turns out that the mechanic didn't attach the wiring harness properly leaving the wiring bundle to slowly wear through. When this bundle made contact with the shroud it shorted causing the LC to instantly stop; it might or might not restart.

The computer also threw all kinds of random codes indicating cylinder spark issues depending on where the engine was when the short occurred.
My poor wife had to get towed out of a busy intersection at rush hour. I had it die on the Capital Beltway commuting to work in rush hour.
It took a long time to figure it out and fix.
These types of things are no fun and dangerous.

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I know how you feel. It can be terrifying to have your vehicle just go dead unpredictably.
All you can think about is stuff like "Well is it going to die in this tunnel? On this bridge? On this highway with no shoulder?"
Once it does that you can't relax. Driving becomes a nightmare.

Had any service work done on it like a timing belt, water pump, alternator etc?
This is what an excellent mechanic asked me when I finally found a place that fixed my 100 series LC that did almost the same thing.
It's not that I think a bad timing belt would be causing your symptoms like the dash going dark. What I'm suggesting is that you might have an issue due to service work damaging or bumping a wiring harness loose. And it wouldn't have to be recent either.

So how could replacing a timing belt and water pump result in the car dying suddenly and unpredictably?

What happened to me on my 100 series was that the metal shroud at the base of the fan slowly wore through the wiring harness to the crank sensor 2 years after the replacement of a timing belt & water pump. It turns out that the mechanic didn't attach the wiring harness properly leaving the wiring bundle to slowly wear through. When this bundle made contact with the shroud it shorted causing the LC to instantly stop; it might or might not restart.

The computer also threw all kinds of random codes indicating cylinder spark issues depending on where the engine was when the short occurred.
My poor wife had to get towed out of a busy intersection at rush hour. I had it die on the Capital Beltway commuting to work in rush hour.
It took a long time to figure it out and fix.
These types of things are no fun and dangerous.

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Wow! I’m sure that was quite scary having your 100 act up like that. You’re, right it definitely does not give me confidence when driving around.

I have actually had a few big repairs over the past 3 years. First was the valley plate leak. Shorty after that, the radiator went out. Then about 7 months ago, there was a leak from the transmission to transfer case that I had repaired. I also had the oil changed last week. Something definitely could have been moved or not put back correctly.

I have the skid plates off in preparation to install some new plates from Bud Built. Before I put the new ones on, I’ll look around underneath and see if I can find anything that may be related to a recent repair.
 
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Thanks for the replies everyone, this is definitely a weird issue. It seems like it would be electrical related since the dash went dark and the lights shut off for a second. I'll try to dig further into that area tomorrow. I am running the Slee kit for the group 31 battery and it has standard posts. I drove around a bit today and everything seemed normal again. I would think if it is fuel pump related I would get some sort of code but who knows. I might bring it into the dealer and have them take a look at the fuel pump/ fuel pump ECU since I'm still covered under the extended warranty for 3k miles.

When the vehicle died and then started again, it almost felt like I was in a manual transmission car coasting down the hill and then popped the clutch to get it started. Very weird...

FWIW, please check that your terminal extensions are tight on the military terminals. We have also seen some cases in high corrosion areas where the terminals corrode between the aluminum and the military terminals and cause a bad contact. If that is the case, the military terminal typically gets pitted. If so, clean, dress with a file, apply di-electric grease and re-install. You can also measure voltage while starting on the terminal directly, and then on the terminal extension to see if there is a voltage drop.

As for the winch, not sure on why the ground would get hot on the winch with no load on the winch.
 

edwardg

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I had a problem with the wiring at the fuel pump this past summer which caused the truck to spontaneously stop running on the highway. There was some corrosion on the connector causing intermittent connectivity.

HOWEVER, the rest of the truck’s electrics remained on and it didn’t throw any codes whatsoever.

A bad/shorted ground will cause everything to die as you’re describing though.
 

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