[da-coder]

So what IMA cars have higher voltage packs?
Do these dc-dc converters and inverters use the same data stream for control as the CR-Z etc? I bet they are similar.

So would a CRV 2019 or Jazz dc-dc and inverter work in a CR-Z????? Only one way to find out..

But before I start buying expensive parts.........

Do we know (yet) what the max possible power we can ask of the IMA motor is?
If you need any programming done, feel free to HMU. I have a lot of free time currently.

 

[da-coder]

@rockyola do you have 2013 wiring diagrams? I need brake and clutch switch for manual. Also ecu pinout and ima wiring. So prety much all of it.

You Can Get A FSM Online From Honda For Free

UPDATE: as of today (2/Feb/2023) this no longer works. Was nice while it lasted. So i was looking at maintenance information on owners.honda.com (where i usually keep my service history / get owners manual etc) and i noticed something interesting... If you go to Vehicle Info > Maintenance...

www.crzforum.com

@da-coder do you know arduino? I have 2 projects thst need coding.

I've dabbled. But I am by no means an expert. I do like programming in ARM assembly though.
The Arduino studio, iirc, is C.

 

[da-coder]

@PeterPerkins I am of the opinion that we just swap the entirety of the battery pack / inverter unit.
That way, we've only got things like current, voltage, and position sensor data to worry about.

Also the prices of just a used inverter is outrageous. Could buy a battery pack / PCU unit entirely instead.
They both are listed for around $500 USD. Not sure if this includes the inverter on the battery packs.
Examples: 2018-2020 HONDA ACCORD Battery hybrid battery OEM | eBay & 06-08 HONDA CIVIC HYBRID INVERTER IMA COMPUTER BATTERY CHARGER OEM DC DC | eBay
Prices seem to be all over the place. Guessing it depends on how much life is left on battery.

I spent most of today researching inverters for different Honda models and it seems there are two types: Mitsubishi and Keihin. I believe the use of Mitsubishi is part of their ongoing partnership with GM for electrification?
Ours seems to be Keihin. I think a good place to start is any of the newer models that use this same manufacturer.
I wasn't able to really verify this so disregard.

Seems a good way to find the voltages of the battery packs is this sticker I see on almost all Honda packs.
This is for a 2018 Accord Hybrid:

And this is for a 2014 Accord Hybrid:

Here in the states we have the Acura RLX which appears to also be a 260V battery.
Usually they get the more powerful drivetrains.
The CR-V appears to be a 260V battery as well.

 

[da-coder]

In these newer higher voltage (260V) packs the inverter is up on the engine asfaik.
In the couple of CR-V ones I have disassembled here in UK the battery unit only contains the cells, battery management, contactors/fuses and dc-dc module etc.

Update: I was a doofus and clicked on ILX instead of RLX...

The first Honda here in the us with the hybrid SH-AWD system was the 2014 RLX.
The sport hybrid is a DCT (stator in transmission) instead of the newer E-CVTs.
I suspect it's the same rotor / stator just put in the transmission instead.
They list it at 35kW.

The inverter is packaged like the nu-NSX, in the tunnel. It needs liquid cooling.
I couldn't find any pictures or more details about the PDU.

 

[da-coder]

18 coils just like ours.

The "stator resolver" (position sensor) for the 2014 RLX is 1A810-5P8-004.
Which looks like this:

Aside from the mounting portion, it looks similar and uses the same plug as ours.
I think our position sensors are just three coils (hence 6 pin plug).

I think Acura service data would be the best way to find if the pinouts for the front inverter, within the PDU, are similar to ours.

 

[da-coder]

HCH2 = Honda Civic Hybrid gen 2?

What is the IC on the sensor board? If it's got a part number maybe i can find a datasheet for it's pinout.
If the IC on the sensor board is a current sensor using a magnetic 'u', then there should already be an external resistor we can change to scale the output.
It will be in parallel across the current output and feedback pins.

I'd suggest we use a digital variable resistor in it's place so we can change the % current reading for all three at once.

 

[da-coder]

Can you share an up close picture of the sensor circuit board?

It might follow the same pinout as other current sensors.
On the ones i've used it's been pins 3 and 4.

 

[da-coder]

@da-coder I could send you a phase sensor if you want to play around with it on the bench and see how you can modify (reduce) it's output.

With how simple the circuit is, i don't think i need it in person. I think it's a 3 layer pcb. Could you desolder the IC so i can see the traces underneath it?

It's got to be a quad amp but i can't see where the outputs go.

Is it an open loop or closed loop sensor?

 

[da-coder]

Not quite sure what these tables are, but they are outputs of some sort.
X Axis being RPM, and Y axis is unknown, I haven't seen breakpoints like that, so its definitely something specific to the inverter.

Are you using Ghidra for disassembly or something else?
If you want to share the instructions which read this data, i might be able to help there.

Second one might be max regen with X being the battery temps.
This might help:

 

[da-coder]

If you have an Openport 2.0 i can send you app to dump a whole bin with, which would be greatly helpful for some of the context of the rom, since its missing the first 64kb of data.

Sadly I don't. Peter might though.

 

[da-coder]

Is this for the HCH2 or the CR-Z (Variant?)

Good point, it's for a CR-Z. I'm getting off topic.

 

[da-coder]

HCH2 Phase sensor front/rear with IC (ST?) 0540A1 0622 M56 removed.

So i think i've narrowed it down.

amp 2 operating shunt regulator with red thermistor (R3) and R1, R2, VR1, VR2, C1.
amp 3 being run as differential for the hall effect sensor output.
amp 4 not being used (both inputs are Vcc+).

The resistor and capacitor at the bottom (C2, R8) filter feedback for amp 3.

That leaves amp 1 which I think is changing the hall effect sensor's lower voltage input based on R4.
If not, I don't think it's a quad amp IC. It almost lines up perfectly but not quite.

 

[da-coder]

@da-coder so how would you modify that circuit to reduce the voltage swing for a given + or - current?

Can change the gain on amp 3 by changing R7 and R8.
Transfer function:
Vout = (R7/R5) (V1 - V2) ... R7 = R8, R5 = R6.
So it's a 1:1 change depending on R7.
i.e.:
change output by 2/3...
Vout1 = (2/3) Vout2 ... R7 is the only changing value --> R7.1.
(R7/R5) (V1 - V2) = (2/3) (R7.1/R5) (V1 - V2)
(R7/R5) (V1 - V2) = (2/3) (R7.1/R5) (V1 - V2)
(R7) = (2/3) (R7.1)

I'd suggest just soldering a new resistor in parallel over each.
A 660kΩ (or 680kΩ) on top of R7 and R8 should cause the output to decrease by the same amount as yours.

With desoldering we just need close to 220kΩ in their places.

 

[da-coder]

A variable solution would be good. I wonder if some SPI controlled digipots can be attached on a little daughterboard. Or some other sort of switchable stepped solution.

Well if we aren't worried about EMF interference we can just make one board and run wires from each digital potentiometer to be in parallel (or replace) those 6 resistors.
Then have one microcontroller run all 6.
Could possibly run shielded cables too.

Hacking some 270k resistors into the R7 & R8 positions instead of the 330K oem ones gave a current detection reduction of about 20% which equates to a current increase of +25%.
It's possible to do this mod as well with the inverter pcb in position which is great. A steady hand and good eyesight is needed..

Good to hear!

I think I might have just bought a whole car.

 

[da-coder]

If we want to go variable we should go with what you suggested earlier as it's much easier to wire up.
EDIT: removed for simplicity
I'd use an Arduino and an AD5206.

 

[da-coder]

I'm looking for the type of IC, i see UART (or SPI) pins on it with test points. Can you hook up an adapter and read from them while it's operating?

Ok it looks like a programmable differential dual amplifier. Should be able to reprogram the gain via SPI.

Also if it's a differential signal, can we just change R122 (BCM) to a lower value? If we put in something that's just a tiny bit lower we can remeasure and see the effect.

 

[da-coder]

Testing the battery current sensor on it's own with a 4.7k resistor across the outputs as per the pcb and then changing it to a 4.3k did not result in any voltage changes.

In hindsight the leads are connected straight to the output of an amplifier so i should have known it would compensate for the extra current...

I'm thinking reprogramming via SPI, or putting a voltage divider in are the next best options.

 

[da-coder]

About the IC, i spotted a resistor (R5) and capacitor (C10) on the back connected to two pins through vias.
What is the resistance of R5?
Can you check via meter to see which pins they are connected to?
So far I've got:

10 - ?        11 - ?
09 - ground   12 - ?
08 - ?        13 - ?
07 - ?        14 - vout -
06 - ?        15 - vout +
05 - ?        16 - clock
04 - in       17 - serial data in
03 - in       18 - load
02 - in       19 - chip enable
01 - Vcc      20 - serial data out

 

[da-coder]

Oh interesting 🤔
Thanks!