2023 ES350 multiple system errors and root cause

dnewton3

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Location
Indianapolis, IN
I traveled to KY recently. Arrived at my friend's farm on Thursday evening. Parked my Lexus and didn't start it again until Sunday morning for my return trip home.
When the car started, it immediately displayed 6 (six!) warning lights on the dash. (see attached photos).

The engine ran OK, and the car seemed fine other than the obvious display of malfunctions. No "red lights" were present; they were all just cautionary for system failures. But the brakes worked fine. Steering OK. Engine ran OK. Hmmmmmmm ......

Drove the car home; about 2.5 hours drive. I arranged with my neighbor to put the car up on the his lift and see if we could find any issues. I suspected that perhaps a rodent had perhaps chewed on some wiring, causing all the error codes. But we found nothing out of sorts; no obvious damage, no evidence of nesting, etc. Further, the error codes displayed indicated that several of the malfunction codes were based on the radar systems; pre-collision, secondary-collision, radar cruise control, etc. But when I had the neighbor's wife walk in front of and behind the car, the sensors worked perfectly fine (detecting her presence). And, though the EPB showed error, the electronic parking brake worked perfectly fine. So it was a real conundrum. Why all the error codes when the systems were actually working???

Took it to the dealer on Monday; dropped it off and got a loaner. The next day, I got a call from the service rep. He asked if I had got gas recently ...
I said "Yes - filled up when I arrived in KY, just before I parked." He then explained that the only failures they could find stored were multiple misfire codes in multiple cylinders. The knock sensor values were waaaayyy low, he said. He offered to drain the gas and refill it; I declined. I said I'd just drive it and burn out that load of gas and then refill from a known good source.

When I picked it up, there were no codes present on the dash. It drove fine, as it had before. I ran it down to 1/8th tank and refilled with premium, just to get the octane at a high value. (I normally run regular gas, and have never had problems using regular in that car). The codes never came back.


This is my assessment of the reality of what happened.
- purchased gas; filled from a local station in KY (about 14 gallons)
- the gas probably had a slug of water and/or poor quality gas (not the full volume of 14 gallons, but some small portion)
- the car was driven only a few miles (enough that the existing good gas in the fuel line was expended) and then parked for extended time
- when started, the bad stuff (water, or whatever) had been primed up towards the fuel rails by the short drive a few days prior
- after starting, the bad stuff continued to be consumed, and all manner of Hades broke loose and error codes aplenty were on display
- the long drive home ran out all that crap, whatever it was, and the stored codes were still present (car drove fine; had decent power and no sensible misfiring)
- there were only a couple of start cycles after the bad fuel, and so the system hadn't reset itself yet
- it's possible that if I had simply refilled with good gas on the way home, I could have avoided a trip to the Lexus dealer



I can certainly understand why bad fuel would set a CEL, but why all the other system error codes? It's like the whole car was freaking out just because the engine computer couldn't compensate for the slug of bad fuel.

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Not the battery; I checked both the static and dynamic voltages. And drop from battery to ground. They were all fine.

You're missing the point. It was bad gas that caused the problem. There were no other stored codes and no other damage.

My question is WHY would the CEL also cause all the other error codes?
 
Not the battery; I checked both the static and dynamic voltages. And drop from battery to ground. They were all fine.

You're missing the point. It was bad gas that caused the problem. There were no other stored codes and no other damage.

My question is WHY would the CEL also cause all the other error codes?
Maybe on the same BUS? ON my BMW, if the water pump goes bad, the oil level sensor will throw a code too. I had a TPMS module failure, and everything on that line threw a code.
 
On the same network CAN line; that could be plausible.

I had a similar experience with a friend's 4Runner. We changed spark plugs, and forgot to connect one of the many vacuum lines. So when we started it, it threw not only a CEL, but also codes for the A-Trac and Hill Descent functions. Why would the traction control systems be tied to the ECM?

If all these are tied on the same CAN network, and one of the modules freaks out, it may affect all the others?
 
My question is WHY would the CEL also cause all the other error codes?

I've seen this on newer Honda/Acura and newer Mazda: one discrete fuel system issue (one a simple, cost-free fix, other high pressure fuel pump failure) causes the Apocalypse Dash with unrelated alerts chiming (radar cruise, lane-keep, etc)

My wild a. guess is that this is on purpose because drivers ignore the CEL nowadays (thinking loose gas cap, etc). And the car doesn't know if it's a cost-free fix or you need something major, it just is programmed to light up the dash when certain codes go off.

it does a great job of scaring you to the dealer. i did just what you did, but turned around when the line was too long and the codes did not reappear

YMMV.
 
My question is WHY would the CEL also cause all the other error codes?
This is how Toyota structures their warning system; Honda is doing the same now.

Their thought process is -- if there is a powertrain malfunction it could impact the ability for any safety or adaptive driving systems to function effectively, so those will generate faults as well.
 
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BTW your dealer service department is either excellent or this is a secretly known problem that's just seeing the light of day.
 
On the same network CAN line; that could be plausible.

I had a similar experience with a friend's 4Runner. We changed spark plugs, and forgot to connect one of the many vacuum lines. So when we started it, it threw not only a CEL, but also codes for the A-Trac and Hill Descent functions. Why would the traction control systems be tied to the ECM?

If all these are tied on the same CAN network, and one of the modules freaks out, it may affect all the others?

Not sure how Toyota does it but on my RAM there are 2 buses, one for "interior high speed" (think lighting, accessories, radio, etc) and the other for the "mission critical" stuff (ECU, TCU, ABS, transfer case, etc).

I would think Toyota smart enough to keep the powertrain stuff separate from the accessory type stuff.

ABS (which is how traction control works) and ECM are mission critical, probably on the same bus, so it kinda makes sense.

I would have thought it was a battery issue too, if the bad gas caused a drop in voltage and lit up all the lights that didnt clear afterward, but it look like you ruled that out pretty well.

This is kinda a timely thread because we'll probably be in the market for a new ES350 in the next few months. Gotta get in before there are no V6s left!
 
It was programmed that way so it would scare the driver to get it immediately checked out by the dealership. This is the agenda.
 
Not the battery; I checked both the static and dynamic voltages. And drop from battery to ground. They were all fine.

You're missing the point. It was bad gas that caused the problem. There were no other stored codes and no other damage.

My question is WHY would the CEL also cause all the other error codes?

The battery is the right thing to consider as the first culprit. Good that you tested it.

I have to wonder if the misfires cause a change in the excitation of the alternator, and operation of the loads, and thus there was some fluctuation in voltage, or just a eco-mandated deactivation for self protect.
 
It was programmed that way so it would scare the driver to get it immediately checked out by the dealership. This is the agenda.
Nah, Critic's spot on. The car was signalling "I can barely keep running, I can't do any of that special stuff you desire." Sometimes they even shut off the AC and/or cruise control!

When I got my first Prius with a bad battery module, the dash was a xmas tree with ABS/ VSC/ CEL lights on as well as the giant red exclamation point triangle.

Another true story, wife had her HHR valet parked. Guy was rolling backwards in reverse when he slammed it in drive. How do I know? It threw an invisible code and disabled cruise control.
 
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