Engine overworking with little Turtle Sign on the left

Hi Guys,

reviving an old thread here - however I'm trying to get this hack to work on my NHW10

My NHW10 manual puts the red wire (Pin 22 - THA) and the green wire (Pin 14 - THW)
I tired putting the diode between these two pins, and clamping the voltage to 0.7v (from 2.6v)

however, when I checked the reported coolant temp with TECU, the ECU was still reporting coolant temp as 21 deg C (I hadn't started the engine, I just put it into ready mode)

I tried putting the diode between the green wire (Pin 14 THW) and one of the black ones (Pin 18 - E2), as in the NHW11 manual (which is in English) that was listed as how the temp sensor was wired

That also didn't work.

Can anyone point me as to where I may have gone wrong?

cheers,
Matt

 

I am seeing a pause before the ICE coolant temperature is read by the controller. Let me suggest letting the car start and the engine and see what shows up.

For grins, you might try a variable resistor and see if it doesn't change . . . after trying with the diode and running the engine.

Bob Wilson

 

ah ok - I'll give it a try
on my NHW10, the temp readings looked correct. so when I tried both combinations last night the coolant temp was reading 32 deg C - the engine was cooling down from a drive earlier in the day

this morning when i tried again, coolant temp was reading 20 deg C, again no change whether the diode was in place or not

but both times the engine wasn't actually running - I will try starting the car to see if the temp measurement updates

 

The NHW10 and NHW11 are as different as chalk and cheese, other than they look a like.

The NHW10 apparently has trouble managing it's cells and needed plugging in to a specialised machine to rebalance them. Finding those machines outside of Japan is virtually impossible. I believe one exists in New Zealand and one in the UK where the respective companies charge for their services.

It isn't impossible to resurrect a failing NHW10 but often the costs make it unviable. Try a specialist company in your home market. Maybe also check the 12v as that can throw some weird errors.

The Battery Clinic – Toyota Prius MK1 NHW10 Generation 1 Hybrids

This link also has a list of common NHW10 faults and errors with solutions;

The Battery Clinic – Prius Gen 1

 

For grins, measure the DC voltage at different engine temps. Want to make sure these are the right signals.

Bob Wilson

 

"The NHW10 and NHW11 are as different as chalk and cheese, other than they look a like.

The NHW10 apparently has trouble managing it's cells and needed plugging in to a specialised machine to rebalance them. Finding those machines outside of Japan is virtually impossible. I believe one exists in New Zealand and one in the UK where the respective companies charge for their services.

It isn't impossible to resurrect a failing NHW10 but often the costs make it unviable. Try a specialist company in your home market. Maybe also check the 12v as that can throw some weird errors."

for a bit more background to my particular NHW10 google antiscan aeva NHW10 - first hit
I can't post links just yet
anyway, I have a Lithium battery in my prius now

I have access to a Techno S2000 with the data card - but it's somewhat inferior to the TECU program for my purposes

The Techno S2000 is better for trouble shooting as it can access the data snap shot when an error code is recorded, but that's it's only advantage

The NHW10 and NHW11 both have the same engine wiring - at least according to their manuals - the NHW10 manual is in japanese, but the nhw11 manual is in English.
There are lots of pages that are identical - particularly for the engine

"For grins, measure the DC voltage at different engine temps. Want to make sure these are the right signals."

that's a good idea
I measured 2.6v @ 32 deg C
I'll wait till I go for a drive before I can measure the voltage at a higher temperature

Was Hannah's vehicle a NHW10 or NHW11 out of curiosity?