84Elky

Have read much here and on other forums about IAC/Throttle Follower logic, especially this thread [https://www.thirdgen.org/forums/diy-...llower-8d.html], where RBob and Traxion discussed this issue, but I’m having difficulty connecting the dots. Would appreciate some additional insight.

The attachment shows my IAC and Throttle Follower settings.

Some Questions:
1. Looking at my logs, Commanded IAC Steps max out at approx. 200 during PE. Knowing that, it would appear this max amount might be the sum of:
- 160 IAC Throttle Follower Max Steps
- 40 IAC Throttle Follower Max Steps in Drive
While cruising, Actual Steps minus Commanded Steps approximately equals 40, which is the Max Steps in Drive setting.
Is this a correct interpretation of how “Actual Steps / Commanded Steps” works?

2. At no time do Actual IAC Steps ever exceed 80 in the log, regardless of whether in PE or cruising, even when Commanded Steps = 200. If Throttle Follower Max Steps are 160, why is 80 the max Actual Steps?, Is there something else that needs to be set in the calibration to get more than 80 steps?

None of my reading appeared to cover this.

84Elky

Wow! 60+ views and no one? Many smart people here that know the AUJP code. Interpretation would be appreciated if known.

84Elky

OK, let’s try this. $8d AUJP. Max TF Steps set at 160, Max Steps in Drive set at 40. Both are stock AUJP values. Engine runs and idles great and IAC is at desired level at idle and parks correctly. What could cause the IAC to never exceed 80 steps when commanded steps = 200+ and Max TF Steps = 160?

84Elky

Solved ------------------

The $8D 1227730_8D.ads file downloadable at tunerpro.net has an error. The Value in this file labeled “IAC Commanded” is defined incorrectly. It is referenced as being associated with “Packet Offset” 0x17, 23d. But that offset in the Data Stream is “TPS %”. So when viewing a log file, the column in the log labeled “IAC Commanded Steps” is actually reporting the native TPS % value so it is meaningless. TPS % is reported as (X * 0.3921) and IAC Commanded as native (X). This is not an issue in AUJP_4 as the value is not referenced.

Bottom line, Commanded Number of IAC steps is not reported in the $8D data stream, despite it being a variable in the code defined as L011F.

RBob

iTrader: (1)

The IAC steps for the ALDL stream is in the variable at address $2B (L002B). And is at byte #23 in the data stream. The TPS% is in the next byte at location #24 of the data stream.

The variable L011F is just the added IAC steps from the fans.

RBob.

84Elky

Agree, but that's not the issue I believe he is having. The Log File produced when using the 1227730_8D.ads file downloadable at tunerpro.netreferences a variable labeled "IAC Commanded". As stated in Post #4 above, this variable is incorrectly reported bcause it is not in the datastream and thus not available (see below). Rather, raw TPS% is being reported as "IAC Commanded Steps" because the .ads file is pointing incorrectly to 1-based Byte #24 (0-based #23) of the data stream (see attachment). L002B=IAC Position is correctly reported as 1-based Byte #23, but that is not by definition "Commanded" Steps. This is not a problem with Super AUJP_v4 because "IAC Commanded Steps" is not referenced.

RBob

iTrader: (1)

That is strange, as the 1228830_8D.ads file on Mark's site (Tuner Pro), doesn't have the "IAC Commanded" entry. Only the "IAC Motor Position" entry, which is correct.

I downloaded it on 10/24/2012, and just again checked the current version. They are both identical and correct.

Being you are using an ADX file, maybe the commanded entry was added somewhere else along the way.

RBob.

84Elky

Ok, I’m losing my mind & you sir are correct – BUT - the $8d definition file currently available for download at tunerpro.net (1227730_8D.ads) appears to have been changed. The ads file I downloaded and converted to an adx in Tunerpro was downloaded on 6-22-2011. The “Values” in that file are shown in the attachment and there is one entitled “IAC commanded direction”. My change notes show I later changed the description to “IAC Commanded” since the log file clearly did not show direction – just a value which at the time I “assumed” was Commanded Steps. And as can be seen in the attachment, “IAC commanded direction” is associated with datastream 0-based Byte #23 (#24 1-based) = TPS%.

But what the heck, “Commanded et-al” is now not in the currently available file and all is good. But it could be an issue for anyone still using an older file containing “IAC commanded direction”. I'd be interested if anyone has a file with “IAC commanded direction” as one of the Values. It would save me from pulling out some hair.

Think I’ll have a glass of wine to relieve the brain cramps.