Hello. I have 2007 Toyota alphard hybrid  witch one have no starting problem.  When you trying to start engine works for few seconds and cut off and not starting again. When I disconnecting all batteries and he stay for a while till he reset and it same again( Engine works for few seconds and cut off). A lot off lites on dashboard. I done diagnostic and I get code P3125.  I know it's inverter   malfunction. When I dig deeper I get sub code 496. Maybe someone know what's meen? Maybe someone have same problem? I done a lot off research and looks like everyone have different problems with same code. Maybe someone know exactly where problem can be? Water pump making noise and I think it working fine. Someone said it could be thermostat ,but how thermostat can be problem if engine is not even worming up.

Edited June 26, 20241 yr by Remigijus

2 hours ago, Remigijus said:

Hello. I have 2007 Toyota alphard hybrid  witch one have no starting problem.  When you trying to start engine works for few seconds and cut off and not starting again. When I disconnecting all batteries and he stay for a while till he reset and it same again( Engine works for few seconds and cut off). A lot off lites on dashboard. I done diagnostic and I get code P3125.  I know it's inverter   malfunction. When I dig deeper I get sub code 496. Maybe someone know what's meen? Maybe someone have same problem? I done a lot off research and looks like everyone have different problems with same code. Maybe someone know exactly where problem can be? Water pump making noise and I think it working fine. Someone said it could be thermostat ,but how thermostat can be problem if engine is not even worming up.

 

Hello Remigijus,

 

Welcome to the Forum.

Check inverter cooling pump 

Inverter colling pump is working. I saw in some video it could be currents sensors or  modules inside inverter,but still can't find what exactly this sub code means.  

I don't have P3125-496 on the list of diagnostic codes I have. I have found THIS, which points to the problem being more complex than the coolant pump sadly.  You'll need to use chrome to translate it from Russian.

I'm already watched Russian videos, they saying what most common problem is green module and this module is responsible for starter generator motor and they showing how to test them. I tested all modules and they are good. If is bad current sensor maybe someone know how to test them?

P3125-496 is a starter generator fault, "Load short circuit due starter motor inverter abnormality" not much help really. If DTC P3125-448 is also shown then goto related diagnosis, however I can't find what this code is.

Thanks for information 👍 I will do more research on this 

On 6/27/2024 at 4:06 PM, Remigijus said:

Thanks for information 👍 I will do more research on this 

Hi, how did you resolve your car's starting problem?

I have a 2007 Alphard, and it refused to start a few days ago. I suspect it has the same problem. I have tried to find a garage to fix it with success:(.

I tried to swap some parts from donor inverter but was same problem car starts run for a while and then shut down and cooling fan comes on. Then I realised maybe inverter getting overheated so I tried to put new cooling paste under modules and problem was gone. Also I changed few cells in battery and was no more faults. 

I've considered cleaning and renewing the heatsink paste as it must be getting crusty by now. How much work was it to get to the modules off?

To the top three modules is not so difficult to get access but is one more module underneath and you need to take inverter  out of the car completely. My advice take some pictures step by step and it will be much easier to put everything back together, put all screws separately do not mixed up. For me it took one day no rushing. Also check other parts where needed cooling paste.