Milone

The car I have is a 2009 GS350 with 180,000 miles on it.

I was driving about 75 and went to pass a car. While passing, the car hit what felt like a power surge and dropped down to 60 mph and continued decreasing. The check engine light started blinking and the traction control came on.

I switched the lever over to the sport or "S" mode to see what gear I was in, and found myself in 4th running about 4,000 rpms. Pedal was to the floor and it was struggling to go any faster and kept declining speed, only speeding up slightly as I started to gain speed coasting downhill in addition to the engine being pinned.

I'm aware that anytime the check engine light comes on, that the trac control light automatically comes on with it as well.

Not very mechanically savvy, so I'm trying to get an idea of what to expect as potential problems before going to a mechanic shop and getting reamed out of the ***.

Thanks for the help!

potatomon

I think when it flashes it means you really shouldn't drive. Get it scanned for codes all we know is you went to pass someone and it surged..once there's actual codes you get a direction to go on.

That's how I fixed my transmission the car gave me a code p2757 I googled it it said one of the reasons is faulty solenoid it seemed like most likely boom tranny fixed.

Then my engine had like 10 codes when I worked in it it told me the timing chain was off, which connectors are disconnected. Scanner is a must have.

Milone

I will admit to having previously been going slightly faster until I turned on that road

potatomon

It's probably just a loose connector or something. Get it scanned asap.
Buy a scanner. The most you should pay anyone to scan your car is $10. Maybe 20 if they spend 10 minutes and tell you how to fix it

ibidu1

iTrader: (1)

When you lost power, did you attempt to restart the car? Was there enough battery juice to start the car? Have you ever replaced the alternator?

Im thinking its your alternator may have crapped out, killing or feeding really low voltage to the whole cars electronics, putting the car in safe mode, therefore the loss in power.

If after you test to see if the alternator is bad. When shopping for a new alternator look for a denso brand, or oem

This video will help you with trying to diagnose it

Milone

The car was still turned on and driving when all this happened. It never killed itself.

I replaced the alternator about two months ago, way before the incident ever actually happened. I've talked to a few people and have come to suspect a solenoid went out as well as transmission fluid/filters needing to be changed even though it is supposedly supposed to last a life time.

I went to dinner after parking the car, then came back an hour later, cranked it up and drove it and it never showed those problems. It was perfectly fine which is what led some friends of mine to believe its a solenoid problem.

tghw

All you and your friends are doing is guessing. It could be at least a dozen different things that caused the problem. These cars are very complex and your chances of being right are slim to none. Get it scanned to find out what's really wrong instead of guessing. It will save you a bunch of time and money.

ibidu1

iTrader: (1)

Did you use a denso/oem or an aftermarket alternator? As tghw stated its best to use a good scanner, and do a drive with it data logging

pbateson

I had on my car had an alternator problem when on the highway. My car had been in the shop for 2 months and replaced the new alternator it Denso brand. It was last year in October.

dramabomb

I agree you should get it scanned, but it doesn't hurt to have a direction so one can plan one's finances. Also, if the problem remedied itself or masked itself on the drive home, it's good to have an idea in case you end up chasing red herrings.

Wouldn't an alternator gradually lose charge ability? Even if your new one is a dud, isn't there some threshold at which the computer senses low output and flashes the battery light? Would that really trigger a limp? Also, you didn't lose electrics. Seems odd.

Was the transmission fluid ever changed? "Lifetime" for Lexus doesn't mean forever. Despite their longevity Lexus is steeped in lease culture like every other manufacturer and have little stake in post-warranty owner satisfaction. The transmissions are overengineered so they will make it past the warranty without Lexus having to shell out free labor, but they won't make 200k. The fluid's detergents and lubricants break down like everyone else's. People generally change it every 60-100k. Have you noticed rough shifts lately or sputters on acceleration? I've noticed from reading the forums that 180,000 miles is about when transmissions that were never serviced start to pop solenoids. It sounds like the car slipped when it was dropping gears. Sorry but if this is the case it's bad news, since the transmissions are "sealed". You might have to replace the whole thing.

Just my two cents though, and it's worth about as much. Definitely get it scanned and looked at.

Best of luck to you.

jahsma

This happened to me! My battery needed replaced. Then about a month later it happened again and I need a new alternator. It more than likely just the battery!

potatomon

These transmissions are tanks. It's never too late to change fluid on it. I essentially ressurected mine with new Toyota atf, slu solenoid.also dropped a crappy paper filter in there for now

FLYIN4D

Most of the car companies say the trans fluid doesn't need changed. That is BS. CHANGE THE FLUID!

Jontay

2010 GS350 AWD, 152k+ miles: Just had the exact same thing happen to me last week. Was cruising along on the highway and then loss of power (significantly reduced), steering wheel vibrating, "check engine" light came on and "traction control" light came on. Immediately pulled car over and left it sit for a couple minutes. Started up normal, lights all cleared and car worked fine. Then, later that day (about 250 highway miles later) it did the same exact thing except this time the engine and traction light did not clear when I restarted.

Took it to the dealer today ($140 diagnostic check) and they said it is an ignition problem and they want to start with changing out the spark plugs as they said they are original and only spec'd fro 120k miles (I'm at just over 150k). Stealer wants additional $520 (that's after they apply the $140 diagnostic charge) to change the 6 plugs and they said plugs cost $18/ea with approx 3 hours labor. Stealer said if not better after replacing plugs then they would start looking into the ignition coils. Seems like they should be able to pinpoint whether it's plugs or coils(?).

Anyway, I'm thinking I'm just going to order some good plugs from RockAuto (or wherever) and have a mechanic friend replace them and go from there.

btw, does anyone know if the scanner is just the ordianary OBD2 scanner that typically connects under the dash below the steering wheel (like most cars) or does Lexus require a special scanner? Any idea where I can find out what the codes mean?

Anyone have plug recommendations?

tghw

That dealer is going to rip you off further. They did not diagnose anything and will charge you $140 for it.

Dealers are a total rip off regarding plug replacement. You can do them yourself in about an hour. There are several very good Youtube tutorials that show you exactly how to do it. Save yourself over $400. You can find plug recommendations in the DIY sticky thread at the top of this forum. You can also buy the plugs from Advance auto.

Yes, the OBDII socket is standard and any auto parts store will scan it for you for free.