Honda CR-Z Hybrid Car Forums banner
61 - 80 of 94 Posts

IMA Enthusiast
Joined
1,635 Posts
Discussion Starter · #61 · (Edited)
There are a few potential deal breaking issues putting an HCH2 IMA into a CR-Z.

The CAN messages may be incompatible and un-correctable.

The CR-Z Rotor position sensor may not be exactly the same as the HCH2. (They look the same electrically etc)
Both IMA motors have 18 stator coils so should be compatible. .

The HDS will not let us do the rotor position calibration if there are any IMA dtc's
Might get lucky with the alignment.... 馃

Probably other stuff I haven't thought about yet..

Almost certainly need a CAN message faker of some sort as the HCH2 has an electric air-con compressor driven by a special IMA powered inverter.
If we take that out something is bound to complain about it being awol!
 

IMA Enthusiast
Joined
1,635 Posts
Discussion Starter · #62 · (Edited)
OK Let's look at the 5v bidirectional battery current sensor. (2.5V = 0A)

Passive circuit component Circuit component Hardware programmer Electronic component Electronic device


Circuit component Passive circuit component Hardware programmer Computer hardware Electric blue


The 20 pin chip is ISC101E (061012) (Google doesn't come up with anything very useful)

If we fool the 3 phase sensors we have to fool the battery current sensor by the same % amount. (let's use 20% for example)

The battery currents sensor has two outputs ISOC- and ISOC+
These are driven directly from the sensor opamp chip outputs. (no series resistors in the sensor)

Inside the BCM is a 4.7k resistor between ISOC- and ISOC+ (Blue marks on pic)

ISOC- line has an 11.8k resistance to ground inside the BCM.
ISOC+line has an 7k resistance to ground inside the BCM.

Circuit component Hardware programmer Passive circuit component Electronic component Electronic engineering


There is then a collection of high precsion resistors in some sort of matrix. :unsure:

Circuit component Hardware programmer Electronic engineering Electronic component Engineering


Rectangle Schematic Font Parallel Pattern


I measured the voltage swings on both sensors outputs in both directions with known currents 10,20,30A

Font Material property Number Screenshot Pattern


Looks like some sort of differential sensor.

Anyway we need to reduce the current it sees (output voltage swing) by 20% to match the phase sensors for the initial current hack testing. :eek:
 

Registered
2014 Honda CR-Z EX CVT
Joined
311 Posts
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.
 

Registered
Joined
48 Posts
There are a few potential deal breaking issues putting an HCH2 IMA into a CR-Z.

The CAN messages may be incompatible and un-correctable.

Almost certainly need a CAN message faker of some sort as the HCH2 has an electric air-con compressor driven by a special IMA powered inverter.
If we take that out something is bound to complain about it being awol!
Both of the above issues can be handled via modification of the rom.
I don't have a module to test writing yet, but i have the assumed code taken care of already. However it would require us to make some modifications to the code side of things for it to work.
Changing canmessages comes really easy once you have a data dump, provided we have enough free space in the rom to hook what we want send to a new function that would either overwrite the data that it sends regularly with what we want to send, then add our data to the rom in the specific packets or just constructing our own canbus packets however we see fit :)
But before i can get there, im going to need that ROM and Ram dump :)
 

Registered
Joined
48 Posts
OK I have a cheap scrap HCH2 on my drive now for data gathering.
It's not driveable on the road but the IMA works and it does move under it's own steam (just)
It will be going to the scrapyard in the spring after I have gathered any data we need and taken the IMA out.
Im currently working on the utility to be as foolproof as possible :D
I might not have it finished this evening(its 1am my time) but i will have it to you by tomorrow at the latest.
 

IMA Enthusiast
Joined
1,635 Posts
Discussion Starter · #71 · (Edited)
You mean when the HDS is talking to the IMA?

The HCH2 has three separate CAN modules in the IMA box.

The BCM (Battery control module)
The MCM (Motor control module/inverter)
The Air Con compressor module.

I assume you want the MCM module ID..
 

IMA Enthusiast
Joined
1,635 Posts
Discussion Starter · #73 · (Edited)
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.
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.
 

Registered
2014 Honda CR-Z EX CVT
Joined
311 Posts
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.
 

Registered
2014 Honda CR-Z EX CVT
Joined
311 Posts
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:
Code:
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
 

IMA Enthusiast
Joined
1,635 Posts
Discussion Starter · #80 ·
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:
Code:
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
R5 & C10 are in parallel and unmarked.
R5 in circuit measures 24R but that may well not be right.

R5 connects to pins 2,3,4 of the IC assuming pin 1 is nearest the dot.

I can't tell which pins are connected to which side/s of R5 due to the very low resistance of the circuit.

My meter says continuity basically between any of the pins 2,3,4 and either side of R5.
 
61 - 80 of 94 Posts
Top