RomRaider

Searched and couldn't find this discussed before...
Did some logging recently, and I'm almost sure that during cranking ECU manages mixture by 'backward' logic, i.e. opening throttle according to Cranking IPW. Searched through ROM in IDA, looking for functions that modify Throttle Opening Angle, and found reference to this table

In A8DH100F address is DBBB0.
However I can't trace X Axis values, they do look like IPW, but in miliseconds, not in microseconds like elsewhere in the ECU.
Can anyone confirm/deny this?

Engine Running Status / Thresholds
Came across this while looking at Cranking throttle, it may be useful for diagnosing hard engine starts. There is a variable that determines if engine is running or cranking and 2 RPM thresholds that set this variable.
In A8DH100F

Raw value is 0 when engine is running, 192 when not, but ignition key in IGN ON/ Craniking position

It's pretty straightforward:
if RPM>500 ECU decides that engine is running
if RPM<300 - it's not, cranking tables are used to determine IPW
Plus some transition logic inbetween.

Tested..
Apparently, values in that table affect both cranking throttle AND initial idle throttle, modifying it can be little dangerous
Assuming x axis values are ipws, I multiplied them by 0.6, factor for ID1000 vs stock 565c. Yes, it increased throttle angle while cranking, like I wanted to, but also made a lot of other weird stuff. Car started to rev match during shifts... sort of))) Which was fun until I found during this throttle blips there is too little vacuum for braking. Now back to stock values, looking forward how to modify cranking throttle only.

Hello There! Sorry for not responding to this earlier. The table data you found is actually a target throttle opening angle at idle while running. The axis here is target throttle idle airflow. So by changing the axis values you were essentially increasing the target throttle opening for a given target airflow number, and that is why you saw the behavior you did. I hope that helps!

I've found the lower tables or data rather in my rom as well. A8dh202x.

I'd like to have a crack at the top table. I'll be looking for it in mine now.

Thanks for the replies.
I've also found 'initial' maf and load tables - ecu uses them when RPM = 0, so if X axis is airflow (really hard to trace here) it would be very simple task to modify throttle at cranking. I'll look the way to describe how to find them.

A8dh202x:
C82A8
C82A4

Edit:
Found the table too! Time to investigate.
Table address:
96470

I may have found the routine that calculates target airflow while cranking in my rom. Haven't looked at it much.

In your rom it's the subroutine at 41d14

So, there are 2 groups 6 16x1 tables each, coolant temp is x axis. Also looking at logs I was under impression, that 0RPM MAF Table (84740 for A8DH100F) is used for cranking, but now it looks much more complicated.

If it's the same tables i saw, I believe they all had the same values. If so then it could be possible to change them all and check. But sounds like neither of us have looked too deep into the ramifications.

Tried this table out tonight. Didn't do any logging, was mostly looking into its throttle hang effect. Was wondering if it would effect idle rpm, but the idle target code I'm sure negates any possibility.

Tried 20% higher in the target throttle angle side.

Also wondering if lowering these will decrease throttle hang as well as it increases it. I notice the throttle doesn't drop as fast as non DBW cars, and it's always bothered me.

It probably will. Also this throttle hang lasts like half second or so before closed loop idle logic kicks in, must be delay set somewhere.
Also, modifying this table didn't help me solving hot start issue.

Small update.
This idle throttle table comes handy when tuning for lightweight flywheel and/or pulley. On a friend's car engine stalled, esp. after reset, so I increased throttle values 25% on lower part of the table and ~10% up top - problem solved!

Works nicely!

Been doing some digging in this area lately. Those tables I found do determine Cranking TPS.

I believe they can be narrowed down to whether the vehicle is stationary and which Idle Map Selection is made.

Basically find out which Idle Speed Map is used when you are cranking by logging the parameter (you should find it's map 1).

Then I should be able to tell you which table specifically is for your cranking.

ONLY problem with this is it may effect your Idle Air Target, and therefore your TPS. It should be able to adapt so you don't notice though.

Damn, forgot a variable. Edit: TGV related.

I've narrowed it to 4 tables for you.
I believe these two are while stationary: 86588, 86600 so it should be one of these, but don't quote me on that.
I believe these two are while moving: 8659C, 86614

I will attempt to track down the variable that picks which of these. That will narrow it down to 2(1).
Edit: Yeah, that's a TON of work. I'll go ahead and say don't count on this ANY time soon.

Don't have my car with me right now, will record some logs in a few days.