Dark9t316

My car was towed to the dealership just earlier and i provided them link to this post. I was assured that they will run extensive tests, but there was no promise of ecu replacement.

toan626

i just got my car back... they not even bother to replace the battery for mine. It seems like they just test out the battery with GR-8 and recharged to 100% again ... Will see if it happened again -,-

Dark9t316

Bruh, even these 2 service advisors at Magnussen Lexus who also have this issue with their IS got their battery replaced (even tho they think their nightmares are over bc they've only had the car die on them once), so all i can think is they gave you the short end of the stick and sent you off to test your luck. I get the feeling that most Lexus techs are unaware of how to handle this issue properly (Magnussen Lexus denied giving me a new battery until i spoke to Corporate). As common as this issue is, every dealership is handling it differently with absolutely no consistency.

LeapFrog

If this happens to my new 3IS I'll get my $75/hour mechanic (not a Lexus tech, BTW) to put a DC voltage and current logger on the battery at splice point 1A and leave the logger in the car until the next failure. Either the battery voltage will drop precipitously without any current draw (bad battery) or something will discharge it. In the latter case we'll know how much current is involved and how long the current draw continues before the battery is discharged. With a bit of intelligence in the data logger we could even get an alert when the current draw is occurring.

Note to Lexus: This is 2016, not 1950. Time to get your mechanics the tools and training they need to do a proper diagnosis of electrical systems.

Dark9t316

I hate to say this, but you have to take it to the dealership. It is under warranty, and should you ever consider taking any legal action regarding this matter, you need to show that they tried to fix the problem.

LeapFrog

I'd do that too, after I had the root cause diagnosed - or at least could eliminate the battery as the cause of the issue. (In reading through the past posts on this topic it seems that some 'Lexus factory' folks already did something similar with several customer vehicles, but it wasn't clear if their diagnosis was what led to the gateway ECU replacements.)

J3ffrey

Just left my car for 9 days in the garage while on vacation.. it started right up, 2016 IS350

Dark9t316

I'm not sure any 2016 models are affected...

Dark9t316

A quick update, i just received a call from the service advisor. They claimed that they can't find anything wrong with the car, and recommended that I go buy a trickle charger. Simply put, they basically said my driving habit is the cause for the battery drain. They said my car does not require a new gateway ecu based on the tests. It is totally unacceptable in my mind that I have to go buy a trickle charger cause the car possibly cant replenish enough power back to the battery based on normal driving habits? Sounds like a bad design if thats the case. I plan to talk to corporate tomorrow to let them know that i am getting my car back without a solution and that if this problem persists, i will purse the lemon law.

rL-gT

Same

Picked mine up Dec 10th. Drove it once on Dec 24th and its been parked since

Started up like a charm just now.

J3ffrey

What are your driving habits? Just so I can compare them to my own..

Dark9t316

Most of my driving are during weekends both saturday and sunday 90%, and once or twice during the week. I'm not taking 5 min drives here, it's usually average 100+ miles during the weekend. It doesnt make sense that my battery would be drained like so.

AndyL

It indeed doesn't make sense. My in-law's Honda Accord has a similar driving habit as you do but even worse -- once or twice during the week and all are short drive -less than 30 minutes local drive and yet they didn't experience any battery drain.

Now back to IS - my 2014 IS finally experienced the battery drain a few days ago-- the car was left in the garage for vacation. I even covered the card keys entirely with aluminium foil and made sure the car did not respond to any of the keys.

3 weeks later, the battery was dead --- even the red security light on the dash was off. I first attempted to resolve the problem with the milder way -- using a battery charger that supplies 2A, 8A or 12A to the battery but to no avail ---- the battery charged only at 2A but the security came back and thought there is a break in. So the taillights and the headlights were flashing with the alarm. Then I contacted my dealership and they determined it is the gateway ECU that needs to be replaced and they said they will order it.

Then next day I tried to jumpstart it with NOCO GB30 which is a jumpstarter battery that I bought a little while ago to prepare for this event. I had to use the manual override as my battery was less than 2V (which the NOCO states that I need to use manual override to jumpstart). Cranked the engine a few times and it worked. (I also waited till the Infotainment reloaded properly before I attempted to crank the engine). I drove the car straight to my dealership in the evening time before they closed. Glad they could manage to provide me with a courtesy car.

It didn't take them too long and I got back the car during the morning today. They replaced Gateway ECU and kept the same battery as the tests were okay. When I returned to my garage, the battery voltage was about 12.9V. After 8 hours, the battery voltage now drops back to normal which is about 12.65V. I hope the problem gets resolved...

FYI -- the gateway ECU is somewhere behind the glove box. The technician needs to remove the glove box in order to replace the ECU. I took the precaution by covering the trim on the glove box with plastic wrap.

Also note that this is indeed a very common problem among 2014 IS which my dealership is aware of it. They didn't argue with me after I explained the situation. Also the part number for the gateway ECU for 2014 IS is different than the one for 2015 IS.

Dark9t316

AndyL, I'm glad that they gave you an ecu replacement without a battle. As for me, Magnussen Lexus plans to send me home with my 2nd new battery, they denied that my problem has anything to do with the ecu. I don't even think the ecu costs very much, they couldn't have handled the situation any worse. I have a feeling my car will die again within the next year.

Which dealership do you go to? I need some references when i talk to corporate tomorrow. Thx.

AndyL

Dark9t316, the dealership is Lexus of Richmond Hill in Canada where their service department is superb. PM'd you for more details of my experience with the battery drain.