Hi All,

I've been searching for answers on this one but am looking for a sanity check before I go and dump a ton of cash into the car

A couple Sundays ago I was merging onto the highway at the end of a long mountain driving trip, and my gas pedal cut out. At the same time, my dash showed "Check hybrid system. Stop the vehicle in a safe place immediately. Contact a dealer". I think there was also a VSC or traction control error (dash flashing between the two) but I don't remember and it wasn't persistent.

I coasted up the nearest off ramp, threw the car in park and restarted it. There was an awful smell - like either something electrical going bad (or how burning clutches or ATF is described) and I was able to limp it into a nearby parking lot.

I tried scanning with Dr. Prius and found no issues with the battery. After giving up on a tow truck driver I gently drove into the nearest parts shop and used their scan tool - no codes found. I also used their 12v battery tester and it checked out fine (it's only 6 months old - no surprises). The smell was worse on the drive over, but now the dash message was gone.

Being in the middle of nowhere, I let it sit overnight at a hotel and had the nearest Toyota dealer pull codes. The drive to the dealer did not make the smell or any error messages or performance issues return. They claimed it was a P3147 info code 239 and quoted $20k for a transmission. They didn't do any diagnostics other than the scan tool - I'm a little incredulous that a transmission would fail on a 145k mile 2008 LS600hL - what do you guys think? (at this point I just put the car on a U-Haul trailer and towed it 300 miles home). I will also note I checked for codes again after getting home using my Blue Driver scanner but could not find that code - just older stuff that I've already resolved. Is that also a red flag on the dealer diagnosis?

There's no wear items or clutches or slipping bands like a normal car. It seems like the error is most commonly associated with the transmission input damper going bad on Priuses and other Lexus Hybrids based off forums but I don't know how much to trust that - it definitely seems more likely to fail. I suppose it could also be the engine or flywheel being cracked but I also have no reason to suspect those as failures.

The issue I'm running into is I don't see a way to check other than dropping the transmission and inspecting the damper and flywheel. I've had two shops turn me down for a 2nd opinion, and I don't think my local Lexus dealer is going to want to do anything other than throw a transmission at it either (for an even crazier price I'd bet). I did manage to get a local hybrid-only shop to give me an appointment for a 2nd opinion next week so I'm not completely stuck for now, and can live without the car.

If the shop also just says replace the transmission - should I drop it myself and check? Put a used unit it? Put a new one in??

Anyways I appreciate any help or advice you guys can add here. Seems like I'm in the right place. Thanks for reading and thanks in advance for any advice

 

my 600 has 213,000 miles on it and never had a issue with the transmission. I Looked in my repair manual, pretty lengthy process to diagnose. I suggest you buy the manuals for your car on eBay. I googled P3147–239 scroll down to charm.li this might help you. good luck

 

Hi Bear2023, Thanks for the advice.

Sounds like actual issues with the transmission are rare on these cars.

Seems to be a slightly different troubleshooting tree than the one I looked at before - looks like there's also a connector that could be bad, or the ECU. It's interesting - this one doesn't mention the damper at all. I wonder why not. Anyway here's the link in case anyone needs it to the charm.li manual
charm.li manual

Looks like I'd need to invest in a techstream setup and figure out how to access the crankshaft pull in this thing to try these myself. Might wait and see if the shop can do it. Seeing more small things that could be the issue is probably good. ECU or connector could definitely explain the smell.

 

Some of those cars had problems with the damper crapping out and causing a problem like yours, this video has some info about it and the second video in that thread shows the damper and flywheel. Of course the dealers automatically want to order a trans...cvt in your case, the assy will have to come out and be diagnosed so that will suck for you.

https://www.clublexus.com/forums/hyb...failure-4.html

 

If you need just the transmission there is one 2nd. hand for an LH600 in Oregon for $1,500:

https://imageappky.car-part.com/imag...ck%23%201293-1

Also, a good number more in other states for less:

https://www.car-part.com

 

Got the car into the local hybrid shop today - codes were not present (cleared 29 miles ago) & they were unable to reproduce. So going to just drive it and see if more problems come up for now. Will probably try and keep the car in town in case it needs a tow.

I did try and floor it, use sport shift to engine brake, etc... a couple times to try and replicate the original issue but got nowhere. I did however notice a few very faint whiffs of the bad smell when starting the car and when getting out. I am not 100% sure but I popped the hood after getting home and I think it may be coming from near the inverter coolant reservoir. Can anyone confirm if this is the approximate location of the inverter? Page 8 of this document shows it there but I found conflicting data on some other documentation while researching. link Should I be worried that the inverter coolant level was at the "low" line after a ~30 minute drive on a level surface?

A note on the smell - I'm not familiar with the smell of burnt coolant but a quick search says "burnt syrup" which does not sound like what we smelled when I had the original issue. It smells more like very hot or burned electronics or insulation (which I'm fairly familiar with as an EE). This makes me suspect that the issue may really be in the inverter. It seems possible it could have gotten inadequate cooling during prolonged mountain driving and overheated. The code being thrown still seems odd, unless it's the inverter which is used to determine that there is a transmission issue?

On the bright side, got great vibes from the shop. They seemed to really know their stuff and didn't charge for a diagnosis and test drive, and were willing to work on it if I need to tow it in (including installing a used transmission if needed). They also mentioned reading this post.

Also thanks all for the help!

 

Can you request the inverter coolant pump to run to confirm it's functioning?

 

Is it the same as a prius where I just out it in IG on mode (press start twice no brake pedal) and look for fluid movement at the fill port?

I was thinking the same thing and planning to check it after work tonight

 

If that would get the pump to turn on sure, I use a scan tool to both command it on and check to confirm the requested state is happening or not

 

Here's a free online manual. I have a bluetooth obd2. BlueDriver. Seems ok. Might be helpful

https://workshop-manuals.com/lexus/l...pand_article=1

 

Alright, with the coolant topped up I ran a pressure test on the inverter reservoir at all 5 psi - no leaks. I also checked it with a test strip - tested fine. Then I tried checking for the pump running using just IG-ON mode - there was absolutely zero fluid moving and I could hear something spinning/ticking very quietly from somewhere under the engine coolant reservoir. Supposedly that is where the inverter pump is located, and I could potentially see the ticking sound being the broken pump.

There was some floaties on the surface of the fluid, but they were tiny and clear, could just be dirt from the engine bay getting in. Not sure if that means anything.

On the other hand, I am not 100% that was enough to get the inverter pump to run on this model. I tried my bluedriver scan tool but it doesn't have any way to force the pump on/off or even see if the computer thinks it's running. Is it time to invest in a techstream setup to check for sure? Another option might be to put the car on jackstands to pull the skid plate off to check for sure if the ticking noise is the pump, but I'm not sure how obvious it will be once I get under there. And if there's any traffic I won't be able to hear it. Maybe a mechanic's stethoscope would work?

Going to try and drive the car to work (~30mi) tomorrow to see if anything happens.

 

Actually, instead of jumping to a techstream, it looks like if I can get to the pump and unplug it I can either put 12V on it to force it on. I bet I can measure the wire harness from the car with a voltmeter to see if it's supposed to be running in IG-ON mode manual page