bclexus

@Hues10 ► Post #19 Yes? No?

What's the closest auto parts store that can read the DTC codes on their code reader?

Lwerewolf

Nope.

As mentioned above - AutoZone/O'reilly/whatever free scan service is around, make sure that you get the codes and that they won't clear them. Skimmed a few threads on priuschat and they seem to be able to pull hybrid codes? Regardless - if it's "free" (minus time/fuel) and it's nearby... might as well.

Alternatively, what I said earlier - get a good bluetooth obd2 adapter (by good I mean vetted - obdlink, carista, vlinker, etc) and use torque or whatever else works for pulling codes off of the hybrid ECU (torque did work for me on a 3GS 450h). Check whether anybody in your surroundings has one already. Also check that whatever you're getting works with iOS if you don't have an android device around. The main hybrid apps list "recommended" adapters:
http://hybridassistant.blogspot.com/p/obd.html
https://priusapp.com/ ("OBD2 to buy" section from the menu at the top)

Alternatively - techstream. You'll need a Windows PC (VM works for me), a compatible adapter ($$$, especially if you go for the recommended Mongoose units) and a license.

bclexus

@Hues10 - I still want to know if you had the fuel pump replaced under the Lexus Support Program. The fuel pump that needs replacing could be what triggered your problem.

My 2018 GS 450h had the inferior fuel pump that needed to be replaced, so I suspect yours might need replacing too - unless you've already had it replaced, which is what I'm trying to find out from you...

Nevada

Your scan tool is only reading PCM faults, the fault causing the warning message is in the Hybrid control module. You need a scan tool that allows you to select each individual module for analysis, you won't find one at Auto Zone.

Hues10

Sorry BCLexus. I never did have the fuel pump replaced as for the past five years, I have not had anything go wrong except the 12V battery going bad in early 2021. That was replaced at the dealer for a cool $500. Oh, I did replace the sunroof seal as well on my own. Other than that, I have done two oil changes on my own since my CPO ran out in May of 21 and a set of Michelin tires from Costco. So, a typical Lexus car so far as far as reliability. See below for the latest update.

Hues10

So here we go. The one last thing I did with the scan tool yesterday (if you look at the picture of it), is the big red "Erase" button. I figured without any error codes detected, what could it hurt to hit the red button. The scanner did its thing, hate to say it, but to me, the messages on it read like when you get a Windows error message. They basically mean nothing to me. So did it do anything to clear the code? I do not know since it does not say, "Hey, I cleared a code that I initially didn't find". I mean it looked like the message had cleared on the display, but I ended up shutting the car off yesterday in disgust since I didn't have anywhere to go. This morning, time to go to Pickleball, start it up, and the Check Hybrid message is now gone. Drove the 10 mile round trip with no issues. So now I have to wait for something to happen, though I do not want it to. All I know, is that I had only driven the car 80 miles in the last two weeks, so was the 12V battery getting low, and tripped some error message? I will keep the charger/tender handy and make sure I charge it up at least once per week. It is interesting that it does not seem there are any 4G GS 450h owners that have said they received the Check Hybrid System error message. At least I somewhat know the car is not kaput right now. Glad I am recently retired, and do not need the car on a daily basis since we have another vehicle to drive. It reminds me of my ML stereo not working when I was using the Mode/Mute button to silence it. I have not used this button since then, and the stereo has had no issues. Lastly, thanks everyone, and I mean everyone for listening, patience with my story, and advice. Sorry I can't pinpoint the issue yet. Will update again if/when it occurs. I only hope it is a long time from now....

bclexus

Next time you take your GS 450h to your Lexus dealer's service department you really should have the fuel pump replaced under the support program at no charge. Read the information in the attached.

2014 – 2015 GS 450h with production date from Mid-September 2013 – Late February 2015 (It might very well include your 2013 GS 450h) and may have triggered your message...

bclexus

We may never know now what caused the message unless it displays again.

I rather doubt your car's 12 volt battery was what triggered the 'Check Hybrid System' message because you said you were already on your way on a trip when the message first displayed. At that time the battery would have been receiving a charge and unlikely at that time to be sensed as weak.

You may want to spend $13 and get this nifty USB adapter with a (±1% accuracy) voltmeter just so you can check on the 12 volt battery by opening the console to see if it's getting weak.

Hues10

Alas, mine is a 2013. So "No Soup for Me". But thanks BCLexus for the thought.

spineman

I replaced my 12 volt battery with an aftermarket Duracell that several members on here said worked for them. 10 years 125k on original battery. I have now been experiencing starting issues as well periodically, and the power tilt seems "slow." I was not aware of the sensor that needs to be connected. Do I need to switch to the OEM battery? If so, is Lexus the only place to buy them?

Does the regenerative braking charge the 12v? TIA!

Im2bz2p345

To be courteous to the OP, unless you're having hybrid error messages/issues, I would create a new topic on your 12V battery issue(s). That way you're not hijacking his topic and readers who are researching hybrid battery error messages don't get confused.

Btw, I am trying to convey this in the most respectful manner - please don't take my message/tone the wrong way,

~ im2bz2p345

spineman

No worries. There was significant writing on the 12v battery here so I was clarifying about what bclexus had posted.

Lwerewolf

If it's a HV battery code, it will come back. If you want to "test" it - try driving it in EV with the AC on until it forces the engine on to charge it - then drive it with a not-so-smooth throttle.

@bclexus there were no engine ECU DTCs so it's extremely unlikely that it was the fuel pump at fault in any capacity.

bclexus

@Hues10 - Here is a neat little device available from Amazon for $28 that reads the battery's voltage and device temperature via Bluetooth on a free app for your smart phone.

Hues10

Wow BCLexus. That little device would save me from checking with the voltmeter and writing down voltage readings on a regular basis. I am going to have to get it as I sent my Bluetooth Scanner back to Amazon since I didn’t realize it would not check Hybrid system error messages. I know, I need Techstream for that. As an update, I have been somewhat diligent in keeping the 12V battery charged, and “knock on wood”, no further issues. Not complaining at all. Just wish someone else would have had such an issue with the Hybrid System error message being related to a low 12V battery. Oh well, I can only hope it was a fluke item like my stereo not working, then all of a sudden working since I no longer use the mode button to mute the system.