ROM Table Discovery & Definitions

[ztan]

Originally Posted by bur****jp

That thread actually had this a few posts from where you linked in:

Ja. The initial post was the raw data that I was seeing intially over CAN, the second post was what I had cleaned up after having a bit of time to fiddle with the CAN bus over the weekend, setting Techstream to log one parameter at a time whilst sniffing the bus.

I couldn't find a Techstream parameter for IAM anywhere, so I figured that it was likely not easily available on the CAN bus.

[burdickjp]

Originally Posted by ztan

Ja. The initial post was the raw data that I was seeing intially over CAN, the second post was what I had cleaned up after having a bit of time to fiddle with the CAN bus over the weekend, setting Techstream to log one parameter at a time whilst sniffing the bus.

I couldn't find a Techstream parameter for IAM anywhere, so I figured that it was likely not easily available on the CAN bus.

Did you ever get the VSC logging with the openport 2.0? I'm having trouble deciphering how to get those addresses into a logcfg.txt

[ztan]

Originally Posted by bur****jp

Did you ever get the VSC logging with the openport 2.0? I'm having trouble deciphering how to get those addresses into a logcfg.txt

No. I asked Mike and Colby a couple of years ago and again more recently.
The OP2 is configured to send its requests to 07E0 (ECU), not 07B0 (VSC). I think to get control of that, we'd need to get a firmware rewrite from Colby.

I think we would have much better CANbus access to all modules at the moment using an Arduino and CANbus shield; I haven't the time to crack it at the moment.

This CANbus talk is getting a bit off topic, but if anyone can point to where the ECU interfaces with the VSC unit; and if the VSC data is put in RAM on the ECU, we can pull the data straight off the ECU with the OP2.

[burdickjp]

Originally Posted by ztan

This CANbus talk is getting a bit off topic, but if anyone can point to where the ECU interfaces with the VSC unit; and if the VSC data is put in RAM on the ECU, we can pull the data straight off the ECU with the OP2.

I apologize for dragging the conversation in the wrong direction. I agree on the arduino, and am in the process of doing that.
I'm eager to hear if this is in RAM in the ECU anywhere.

Sent from my XT1045 using Tapatalk

[ztan]

<Off topic> Examples of CAN requests to ECU using Drew Tech Canbus tools:

Engine on idle, requesting MAF data

OBD Mode 01:
Send:
00 00 07 e0 01 10 (mode 01, PID 10)
Response:
00 00 07 e8 41 10 03 b8 (repsonse 41 (01+40), PID 10, Data 03 B8 (7.68 g/s)

OBD Mode 23:
Send:
00 00 07 e0 23 14 ff f8 7c 70 04 (mode 23, 14:?number of parameters + data length, RAM address FFF87C70, 04:?bytes expected)
Response:
00 00 07 e8 63 41 15 e6 66 (response 63 (23+40), data 4115e666 (IEEE 754 float = 9.37 g/s)

[ztan]

Anyone have any idea what this (FFF884F4 for A01G) may be? I was looking at how data calls are made to get 16 bit sensor data and this one came up: a voltage value gets read from the 16 bit routine and then scaled by a table (defined at 0B1FA8) which reads like a temperature scale; 100 to -40 in 10 degree increments.

Does not match with any other temperature sensors that I log.

[Kodename47]

Not much help with yours @ztan but more of a question for those who are good at discovery.

Been trying to work out why the throttle closes under WOT and am doing some digging around. I don't suppose anyone fancies digging into the throttle angle routines. It's definitely nothing to do with requested angle, however there must be something that causes this. It seems fairly uniform between FI and NA cars too. I've tried testing Requested torque and calculated tq tables but nothing there has yet made any difference.

[ztan]

Shiv asked me to look at an RPM limit problem under boost and there is something interesting in the code worth noting:

Rev Limit A and B have their cut and resume values in different directions (see disassembly pic). No reason for the engineers to do this and Rev Limit B works without hysteresis in the stock ROM which is has 7400 as the first (resume) value and 7200 as the second (cut).

A01G def:

    <table name="Rev Limit A" storageaddress="10C524" />
    <table name="Rev Limit B" storageaddress="10C52C" />

    <table type="2D" name="Rev Limit A" category="Miscellaneous - Limits" storagetype="float" endian="little" sizey="2" userlevel="1">
      <scaling units="Engine Speed (RPM)" expression="x" to_byte="x" format="#" fineincrement="50" coarseincrement="100" />
      <table type="Static Y Axis" name="Rev Limit Fuel Cut" sizey="2">
        <data>On Above</data>
        <data>Off Below</data>
      </table>
      <description>These are the engine speeds at which the rev limiter is engaged and disengaged. When engine speed is equal to or exceeds the 'On' value, fuel cut is active, after which, if engine speed drops below the 'Off' value, fueling is resumed.</description>
    </table>
    <table type="2D" name="Rev Limit B" category="Miscellaneous - Limits" storagetype="float" endian="little" sizey="2" userlevel="1">
      <scaling units="Engine Speed (RPM)" expression="x" to_byte="x" format="#" fineincrement="50" coarseincrement="100" />
      <table type="Static Y Axis" name="Rev Limit Fuel Cut" sizey="2">
        <data>Off Below</data>
        <data>On Above</data>
      </table>
      <description>These are the engine speeds at which the rev limiter is engaged and disengaged. When engine speed is equal to or exceeds the 'On' value, fuel cut is active, after which, if engine speed drops below the 'Off' value, fueling is resumed.</description>
    </table>