The direct manual link is below (aws), start reading page 547. I would just charge (or jumpstart) the 12V battery as per the manual, the gas engine should start and then the normal drive cycles will start charging the hybrid battery.

https://s3.amazonaws.com/lexus.site....U/OM0E213U.pdf

 

How will the 12v battery start the gas engine without a starter motor? All the 12v battery can do is power up the hybrid system, which can then start the engine, but only if the hybrid system is working and there's sufficient charge in the traction battery.

 

I am confused. The NX450h+ has a starter motor (Part Number: 2810024140) so why wouldn't the OP's 500 have one? And if there was no starter motor, what exactly turns over the engine?

 

Err... https://www.lexuspartsdirect.ca/p/Le...8100F0140.html

 

Well the hybrid motor could turn the eCVT gearbox to start the engine I guess. I would follow the sections in the manual, get the 12V battery charged up first (assuming it can still hold a charge) and then proceed with the sections about starting the hybrid system and/or starting the car.

 

Well now I'm confused too.

As I understand it, an electric motor is used to spin the crankshaft and start the engine, which is powered by the traction battery, with the 12v battery just being used to power up the hybrid system. Here's a quote from Lexus Europe website "Significant maintenance savings can be made in the long-term as the hybrid system does not have a clutch, timing belt, starter motor, alternator etc"

https://www.lexus.eu/electrified/sel...ybrid/benefits

I think the OP's best option is to contact Lexus and ask them what the possible options are for getting his particular car started and charged.

 

They also have alternators. Part Number: 270600W020 I don't know what Lexus.EU is putting out there. I do know there is an inverter/generator, but AFAIK it is for charging the traction battery and MAYBE the 12v battery although is more likely charged by the alternator.

 

I'm pretty sure that the EU info is correct, and can only imagine that the alternator part number is for the non hybrid version. I have an RX 450h (2009) and there's definitely no starter motor or alternator. In fact I can't see how an alternator would be much good to run things as they're belt driven from the engine and the engine doesn't always run in a hybrd, and besides, I have no belt for one. Which is also why the power steering is also electric and not hydraulic. Thinking alound, if the engine was started by a starter motor, then you'd not only hear it when you start the car (which I don't), but would also hear it every time the engine restarted while driving (which I also don't).

My limited understanding is that (at least in my hybrid) the 12v battery fires up the hybrid system, which spins the engine when needed, and the 12v battery is charged by the hybrid battery, via the inverter/generator. As a consequence, there's no need for an alternator as the engine and braking system only charge the traction battery, which in turn charges the 12v battery.

I will caveat all thsi by saying that this is how my car works, and have no idea if these hybrid fundamentals have been changed on newer cars.

 

FWIW, the alternator part number says it is for the hybrid version. I have to take a look under the hood.

 

That would be interesting to know. I take it you have a newer model year. As a matter of interest do you hear a starter motor turning over the engine when you start the car?

I've always thought it would make sense for the engine to have the capability to start/run independently from the hybrid system, as if the hybrid battery/system failed then you could still drive the car like a regular one. Maybe that's been done on newer models.

 

I definitely hear something when the ICE engine starts up. 2023 350h.

 

My understanding is that MG1 acts as the starter and that the inverter supplies 12v for the low voltage system and charging the 12v battery. I've watched WeberAuto's and The Car Care Nut's videos on how the RAV4 hybrids work, and they both say MG1 starts the engine. I'd be surprised if they added a seperate starter motor and alternator to systems otherwise based on the RAV4 hybrids.

I do know that, when I tried doing a 12v battery test on our RX450h+, to establish a baseline, the tester never recognized that the engine had started, I'm assuming because there was no drawdown on the 12v system, because the starter motor(MG1) draws from the High Voltage battery, not the 12v battery.

 

Just looked under the hood of our RX450h+. The spot where an alternator would go is empty and there is no belt drive.

 

I wonder if the OP ever got this sorted?