"DE-Tuning" 2005 Hemi - This should be a first !

[JoshCP527]

Well the weather is finally good enough to do a real test drive. Car was just up on blocks before.

Regarding the Torque Management issue, I am testing fooling the APPS with a couple of resistors to simulate reducing throttle pedal position. Seems to work but am getting a DTC P2138 - APPS Voltage Correlation. I need to refine my resistors !!

Todays question is - Engine idles at approx 2000 rpm when I am coasting to a stop sign , foot off Accelerator Pedal. When I actually stop (or just before) RPM drops to 624 rpm just like is set in the idle tables. On a 2800 lb car, 2000 rpm is enough to keep it moving and you really need to use the brakes to stop. On startup, engine starts and immediately drops to 624 rpm as expected.

Any help is appreciated ! Thanks .

Attachment 130350

The rolling cruise is from trq table stuff. Pull friction trq out where it coasts down at and the tb base voltage will follow for the less trq. Torque Model/Loss/Base table 12882.

It is a jugle also so you might have to re do ve decel mapping and what not.

[TaylorJ]

rays04gtx -- sent you a PM !!

Ray can be a nite mare to get a hold of, nothing personal..........Azerbaijan starting Tuesday and he'll be there till 5/1 on his Consulting Gig,then off to Miami week of 5/3, at least he'll be state side till 5/15, then off to Emilia-Romagna region of Italy.......don't know about you but I would like a 6 figure retirement gig myself.

[TaylorJ]

Well the weather is finally good enough to do a real test drive. Car was just up on blocks before.

Regarding the Torque Management issue, I am testing fooling the APPS with a couple of resistors to simulate reducing throttle pedal position. Seems to work but am getting a DTC P2138 - APPS Voltage Correlation. I need to refine my resistors !!

Todays question is - Engine idles at approx 2000 rpm when I am coasting to a stop sign , foot off Accelerator Pedal. When I actually stop (or just before) RPM drops to 624 rpm just like is set in the idle tables. On a 2800 lb car, 2000 rpm is enough to keep it moving and you really need to use the brakes to stop. On startup, engine starts and immediately drops to 624 rpm as expected.

Any help is appreciated ! Thanks .

Attachment 130350

Posting a Log will help a lot,

Need Channels : Calculated Load, Powertrain request, Accelerator Voltage, Throttle Position (both Voltage and Percentage( ratio) and at least on of the Total Ve (bank 1 preferability).

Couple of things going on here.

your OS is getting mixed information as it's deaccelerating, it's been told it's a manual trans , which doesn't correlate with Tq request and load calculations feedback it's receiving........your sideways 904 has more "drag" then any manual trans.

your APPS "mods" are disagreeing with Power%Request and Expected pedal tables, which on the way up is fine but once you let off the gas , it's acting like a chicken with it's head cut off.
you set all Idles to 624 in 35500/35502/35504/35506 which is fine but Tables 35526/35528 have to match......... do your self a favor and tables 35520/35523 have values Higher then 624......which will confuse the computer when it needs those values.
you say it's dropping to 624 just as you stop.......that's because @3 MPH the OS jumps to the Idle tables.......up the MPH in table 44216 and 12393 same value (IE 5MPH in 44216 and 12393) that'll help.
P0700 is still checked in Mil column.


Looking at your " Tune history there are some things that were changed prior to you buying/Receiving this ECU.
[ECM] 12981 - Fuel Trim Cell RPM Hyst: RPM hysteresis value; is an issue............should 64000 RPM , no need to mess with it.
[ECM] 44448 - FA WOT Delay VSS Min: Above this vehicle speed, WOT Delay is active; needs to be 127.5MPH , Not 15. the 04s by nature don't have a WOT delay, but with this table being Mapped out if the value is changed it negatively affects the WOT table.
Idle>Air flow ............it ALL needs to go back to stock

[acln99]

Thanks for reply!! - I looked up table Torque Model/Loss/Base table 12882. Don't actually understand it or why it exists. In my setup there is very little load on engine, A/C, alternator, ps and a very light car.

Could I change all values to zero ??

[acln99]

TaylorJ thanks for all the info - I didn't see your response when I posted just 2 hours ago.

Yes - this is a used PCM that purchased with what I thought was a factory 56030033AI Flash. ( 2004 Ram 2500 manual trans )

It was flashed into a PCM that was originally 56029161AC ( 2004 RAM 1500 Automatic without AWD transfer case. )

I'm surprised that you can tell all that in the "tune" I uploaded !!

LOL "sideways 904" - I agree ( actually - straight 904 in this model ) .
Still do not understand why they take into account "drag" - unless they are trying to avoid - "engine braking" . I suspect that is a whole other topic with torque convertor lockup etc.

I have disconnected the APPS mod for for further testing. I found the high idle while testing APPS mod.

I changed the 35526/35528 to match and also changed 35520 & 35523 to 648 rpm.

I changed 44216 to 5MPH - can I actually increase it to 10mph ?
I can't find a 12393 !!

Thanks for pointing out MIL P0700 !

I corrected 12981 and 44448. I will look for a "stock" tune to compare more settings.

Thank you for ALL your input !!

Earlier today I tried to Flash PCM with a few changes suggested by JoshCP527 - ie 12882 .

The Flash process failed on the ERASE phase. I now have to solve that issue first. It worked fine on the last update !!

[PurpleRam]

VSS idle speed…… yes you can go to 10pm, don’t go any higher, what I would do is try 5,then 7,if need be 10mph,
12882 , is a complex set of algorithms that includes, calculate load, power trainrequest, Tq airflow ……… those #s in the table represent the total Tq loss the engine is theoretically experiencing, since you have less “drag” now , you can decrease some of the lower rpm area’s in the table.

Try decreasing some of the lower #s by 5%, see how it reacts BUT YOU CAN NOT zero the table. Also tq/airflow tables will need some attention eventually.

[PurpleRam]

VSS idle speed…… yes you can go to 10pm, don’t go any higher, what I would do is try 5,then 7,if need be 10mph,
12882 , is a complex set of algorithms that includes, calculate load, power trainrequest, Tq airflow ……… those #s in the table represent the total Tq loss the engine is theoretically experiencing, since you have less “drag” now , you can decrease some of the lower rpm area’s in the table.

Try decreasing some of the lower #s by 5%, see how it reacts BUT YOU CAN NOT zero the table. Also tq/airflow tables will need some attention eventually.

There will be spots on the 12882 table that can be 0 , but you can not zero the table, wanted to clarify that last post.

[acln99]

It stopped snowing again and was able to test the updated tune. At startup idle immediately returns to 650 rpm. Turning on A/C - idle becomes 800 rpm.
This is all good !!
When driving at 40 -50 mph and let off on gas and put car in neutral - rpm stays at approx 2000 rpm until Vehicle speed drops to about 10 mph. Then drops to 650 rpm.

Again - I would like rpm to drop when you take foot off gas pedal. Could this have anything to do with a "clutch" dis-engage switch. On a 2004 Ram with Manual transmission, does engine idle down when you press in the clutch at highway speed ??

attached is my last tune.

Thanks again for any and ALL help...

2001hemiprowler-write3.hpt

[acln99]

I looked up a 2011 5.7 Ram tune and saw that table 12882 was completely different.
2011 values are a lot smaller but is based on Torque as opposed to MAP.

Could this be my problem ?


12882.png

[rays04gtx]

I looked up a 2011 5.7 Ram tune and saw that table 12882 was completely different.
2011 values are a lot smaller but is based on Torque as opposed to MAP.

Could this be my problem ?


12882.png

No,

Try this tune, the changes are listed in the calibration details,

as for the "loss table" what you'll have to do there is trial and error

Attached is your current table, I would try and reduce Tq values by .95% in the red circled area, if that makes it better, go another .95% reduction.