Help needed with a non running / non powered on gs450h

Trosini · February 27, 2023

Hi all

I have a 06 GS450h, that doesn't run or powers on.

It had a few cells replaced throughout the years, some of it was done by not very reputable service providers, some has been changed by me and it's a bit of a mess.

Last time I had a check hybrid Battery notification, I thought I will change the cells as usual and it will be fine.

When changing the cells, I checked the voltages, the connections and it all seemed to be fine / nothing abnormal.

I started it up and all of the previous error messages were still present, I managed to scan it with proper software and it gave me P0AFA P3004 C1259 C1310 B2243 errors.

Within a minute or two, the car powered off and since then I was never able to power it on.

The car doesn't register the key fob, although the 12v Battery works.

We tried changing the 12v, checking most of the fuses, cables and we are thinking that it's the hv inverter now.

Likely there is a cable shorting somewhere?

Anyone has any tips?

Steven Lockey · February 28, 2023

Hmmm, odd.

The high voltage circuit shouldn't even try and power on if you just press the power button without pressing the brake.
That suggests the issue isn't with the hybrid system. Even if that is completely dead, you should be able to turn the car
on, just not actually start the engine or get it into ready mode.

Kinda suggests you might have a computer or wiring issue.

Herbie · February 28, 2023

On 2/27/2023 at 2:34 PM, Trosini said:

The car doesn't register the key fob, although the 12v battery works.

There's two functions of the key fob. One is the central locking and the other is the immobiliser, so when you say that the car doesn't register the fob, what exactly do you mean?

I know from memory that P0AFA is Hybrid System Voltage Low, so check that you've connected the voltage sensor back up correctly. Also check that the Service Plug Grip is replaced correctly.

You say you managed to scan it "with proper software" - was that Techstream? As far as I know, Techstream is the only one that gives the sub-codes as well as the main codes and this is very important. If you look at the screendump below, you'll see that P3004 covers six different problems and only the sub-codes differentiate them for you.

NemesisUK · March 1, 2023

What happens (if anything) if you hold the Lexus emblem side of the key fob against the face of the Power button?

Trosini · March 3, 2023

On 2/28/2023 at 10:06 PM, Steven Lockey said:

Hmmm, odd.

The high voltage circuit shouldn't even try and power on if you just press the power button without pressing the brake.
That suggests the issue isn't with the hybrid system. Even if that is completely dead, you should be able to turn the car
on, just not actually start the engine or get it into ready mode.

Kinda suggests you might have a computer or wiring issue.

Odd indeed.

EDIT: Found text logs of our troubleshooting.

This was the first thing we found:

All of the pins were intact, but the orange connector to the orange plug had signs of charcoal.

EDIT: I had a few sparks from this black cable upon plugging it all back in.

Luckily I was wearing HV gloves.

The actual pictures are from google, as we didn't take pictures of any of the troubleshooting.

The bus bars and connectors are intact and showing correct voltage in series.

We tried changing wiring frame harness #2, that didn't do anything.

On 2/28/2023 at 11:13 PM, Herbie said:

There's two functions of the key fob. One is the central locking and the other is the immobiliser, so when you say that the car doesn't register the fob, what exactly do you mean?

I know from memory that P0AFA is Hybrid System Voltage Low, so check that you've connected the voltage sensor back up correctly. Also check that the Service Plug Grip is replaced correctly.

You say you managed to scan it "with proper software" - was that Techstream? As far as I know, Techstream is the only one that gives the sub-codes as well as the main codes and this is very important. If you look at the screendump below, you'll see that P3004 covers six different problems and only the sub-codes differentiate them for you.

By not registering the fob, I mean that I can not start the car or unlock the steering lock with the key, as when I am hovering the key above the start button, there's no response.

Which voltage senser are you referring to?

Yes, that was scanned with Techstream and the codes provided were accurate representation of the car's short, but upcoming future...

On 3/1/2023 at 7:19 AM, NemesisUK said:

What happens (if anything) if you hold the Lexus emblem side of the key fob against the face of the Power button?

Nothing at all, I'm afraid.

I have spoken to some other enthusiasts and their suggestion was that it's likely related to bus bars and connectors, but our troubleshooting suggested that those were fine, albeit not perfect as the copper bus bars have seen some use.

NemesisUK · March 3, 2023

Have you changed the Battery in the fob?

Trosini · March 3, 2023

2 minutes ago, NemesisUK said:

Have you changed the battery in the fob?

Yes, I have done all the basic troubleshooting straight away both the Battery fob and the 12v were fully charged and new.

Steven Lockey · March 6, 2023

Yeah, what you've posted suggests either a issue with the computer or the wiring.

Computer should boot up regardless of the state of the hybrid system. It runs happily off the 12V.
That sounds like a fun one to try and fix. Good luck!

royoftherovers · March 6, 2023

On 2/27/2023 at 2:34 PM, Trosini said:

Hi all

I have a 06 GS450h, that doesn't run or powers on.

It had a few cells replaced throughout the years, some of it was done by not very reputable service providers, some has been changed by me and it's a bit of a mess.

Last time I had a check hybrid battery notification, I thought I will change the cells as usual and it will be fine.

When changing the cells, I checked the voltages, the connections and it all seemed to be fine / nothing abnormal.

I started it up and all of the previous error messages were still present, I managed to scan it with proper software and it gave me P0AFA P3004 C1259 C1310 B2243 errors.

Within a minute or two, the car powered off and since then I was never able to power it on.

The car doesn't register the key fob, although the 12v battery works.

We tried changing the 12v, checking most of the fuses, cables and we are thinking that it's the hv inverter now.

Likely there is a cable shorting somewhere?

Anyone has any tips?

Why don`t you have a telephone conversation with Richard of Hybrid Battery Solutions, he is based near to you at Northampton and is a Member of this Forum ? https://www.hybridbatterysolutions.co.uk/