Hi All.
i have enjoed for a long time reading posts, i'm on .y third one now.
i've recently bought a dead rx450h, with the view of repairing it to keep it.
got techstream and other fault finding toys.
first set of codes were,
P0A1A no inf
P0A1B no inf
P0A1C 799
P0A40 500
P0A46 671
P0A4C 513
initially all pointed at the inverter,this was replaced with a working second hand unit. identical codes appeared (highly unlikelly assuming the inverter was faulty and a unit was sourced with identical internal faukts) this leads me to believe the replaced unit might have been ok.so more fault finding was done, following the repair menual. this lead me to the pcm (power control module) also replaced, no luck; last update the traction battery is arround 29% charge, low to start the ice.i am begining to think the battery condition might be an issue,at the beginning of my journey i did ooen the top of the battet
ry to inspect the junction box for water ingress damage, it looked ok and put back together!now feel that the issue is in other areas. reaching out for experience and or opinions. thanks in advance

 

From what I've seen, faults can be caused by something as simple as a weak/dead 12v battery, through to problems with the inverter, traction batttery, electronic control units and/or the wiring connecting them all.

My personal view is that the experience and opinion of others, whilst true for them, might well lead you to replacing more parts that might not resolve the problem. Ultimately, it may be cheaper in the long run to find a hybrid sytem specialist to accurately diagnose the issue, before throwing more parts at it, so you only have to replace what's necessary.

Just my opinion though.

 

Detect the inverter line, I hope the original owner did not install anti-theft equipmen.
Are there any other error codes?

 

When was the vehicle driven/functioned last time?

I do not trust the error codes before I am satisfied that the 12v battery [for the ice] and high voltage traction battery for hybrid side are in good working order.

Another thing about the hybrid vehicle is that if the traction battery falls below working threshold, then the vehicle is disabled and you have to take steps to charge up the traction battery. This discharged state can happen when the vehicle is not run for a long time [3 weeks or so]. Hybrid shops and the dealer should have the means and know how to charge the traction battery.

Salim
PS: You need working traction battery to spin the electric motor which acts a starter motor for the ICE. Once ICE runs, it spins the generator/motor to charge the traction motor. The hybrid and ICE are intertwined ... personally I wish Lexus had 2 independent systems, where if hybrid is not-functioning the ICE should have been sufficient.

 

Hi, how is your car now? did you fix the problem? i have exact same DTC with your car. can you help me fix my car? thank you

 

Hi.

There is another coder related to HV control system regeneration malfunction. this is normal when the inverter generator stops working. as the regen utilizes the electric motor front and back by turning the motors to generators....etc etc......

 

Hi Ianex.

No luck. little time to look into it.
Have you got techstream?
What codes do you get?

 

I scan With gscan. This are the DTC

 

Hi Ianex,

Thanks for sharing.
it looks like there is another page judging by the description.
do you have access to the inf codes that go along side the ISO diagnostics code?
the errors are the same at least what its shown of the picture.
will you be able to share the rest of the dtc description. i will capture what i have and share!
glad to collaborate to see if we have identical issue and can find the resolution!
one thing i have seen in the crankshaft angle oscillates, this suggests there is electrical noise ground, i have put an oscilloscope on the crankshaft signal, resolver signals both motor gen at front and the one at back........they all share similar electrical noise..........did your car just died on you?

 

Hi Ianex,
this are the codes I get with techstream. there are

 

Were you able to fix it? I have the same error codes!!!

 

Same error codes --> as in post #1 of this thread or the general fail warning in the dash?

A bit of history will help, like ode reading, when did it run without issues? what was done recently?

Salim

 

Hi Juthi,

do you have a screenshot of the error codes?
any other codes?

 

The car shows these codes. P0A1A, P0A1B, P0A1C, P0A40, P0A41, P0A46, P0A4B, P0A4C. Initially, there was a leak in the right axle, most of the transmission oil drained out while I was driving back from NY to PA. Now the car shows warning signs of 'check the hybrid system', 'check awd system' and 'check brake system'. I remember putting the traction off last time while I was driving. Now the car has a triangle of death sign. It does not start at all. I went to the dealership. They said it needs transmission replacement. One of the other garages said it's the inverter that is needed. I am at a loss what to do. I added transmission oil and sealed the leak. Still, the warnings are there. I tried manual resetting by battery disconnection, hybrid switch disconnection, and fuse removal for a while. Then the car initially shows it is reset but there is no ready button. But when it gets power from a jump battery, the system reloads and the same warning signs come back!

 

If the transmission was run without lubricant, it would lead to mechanical breakdown.

If the dealer really investigated the problem, then that is the most reliable diagnosis. If on the other hand, their diagnosis was solely based on customer telling them the trans was run with low/no fluid then it is a diagnosis based on verbal input. It might be worth confirming that the dealership actually made the diagnosis based on testing. Some test you can do is by shifting the gear in "N" and spinning the wheels and or drain fluid and see if the fluid is clear or has particles ... may require removing the pan.

Indépendant mechanic's diagnosis would be a secondary in my opinion. I am also aware that the dealership's diagnosis might be partial and they may find inverter as a problem after they replace the transmission.

You can get more input from the net, but at the end [expected] expert and professional mechanics who have done on hand inspection should be deemed to be more reliable than enthusiasts in diagnosing the issue(s).

Salim

PS: If I were you, I might like to get a third opinion.