• Sign Up! To view all forums and unlock additional cool features

    Welcome to the #1 Dodge, Jeep and RAM Forum dedicated to FCA owners and enthusiasts. Register for an account, it's free and it's easy, so don't hesitate to join the SRT Forum today!


Cylinder de-activation is driving me insane.

fumanchu182

3000 Posts Club
Vendor
Premium Account
U.S. Navy Veteran
Donating Member
9 Second Best E/T
HFCOTM
Member ID
#2366
Messages
3,489
Reactions
8,487
Likes
302
City
Pasadena
State
MD
Country
United States
Vehicle
2015 Challenger SRT Hellcat
#1
So if someone has .02 cents they'd like to share I'm all ears. Today once again after a pull, cylinder 8 said bye bye. Pulled over, shut the car off, turned it back on and it came right back. There are no mechanical issues with the cylinder at all. The PCM is doing something it shouldn't be doing and I don't know how to stop it.

Here is a screenshot of the logs.
1686275046848.png
They are also attached as a log. In the tune I have turned of everything I can think of.
1686275355622.png
[ECM] 45667 - Misfire RPM Min: Below this value Misfire will be disabled. - As you can see I never see 8160 rpm so this should be moved out of the way.
1686275523802.png
[ECM] 4049 - Catalyst Damage Noise Threshold: Noise threshold per cylinder to trigger fault.
[ECM] 4049 - Catalyst Damage Noise Threshold: Noise threshold per cylinder to trigger fault.
^^^^^ I have no ideas what these tables are and left them alone... Does anyone have any tips or trick for this?

1686275599225.png
[ECM] 39209 - Weighted Catalyst Misfire: Weighted Catalyst Misfire vs RPM vs MAP. - I maxed out these values, HP Tuners will not let me go any higher. This could be a cause, I managed more than 255 misfires while fucking around and well here I am.

1686276026851.png
This table is a clusterfuck. Even with parameter access I still can't edit it, maybe a bug in HP Tuners? This could be interfering but my hands are tied. Also updated today to 5.1.1220 beta and it is not editable still. I'll reach out to HP Tuners on this one, also reached out on the @ostmike thread to see if he can edit this able. @Jon-MooredPerformanceLLC can you edit this table?

1686276237137.png
I have no idea wtf this is for. I know the hellcat firing order is:
1686276329483.png
These are intimately linked but I haven't figured it out, can someone explain this?

1686276662016.png
Raised temps to 300F, definitely not seeing this temperature. For some reason the labels in the table are not correct, wonder if this is an issue.

If anyone can help it would be appreciated. Kinda at my wits end...
 


Attachments

1971demon

Poster Club Hall of Fame
Founding Member
Member ID
#1122
Messages
18,477
Reactions
40,662
Likes
352
City
Orchard Park
State
NY
Country
United States
Vehicle
2018 Demon 2016 Hellcat
#2
Way above my pay grade....somebody must be able to figure it out for you GL
 


Bobo

2000 Posts Club
HFCOTM
Member ID
#14500
Messages
2,280
Reactions
6,434
Likes
302
City
Fremont
State
OH
Country
United States
Vehicle
2022 Dodge Challenger Super Stock
#3
Didn't know these cars had cylinder deactivation???
 


MiHiHemi

500 Posts Club
Founding Member
Member ID
#1016
Messages
805
Reactions
2,425
Likes
132
City
Parker
State
CO
Country
United States
Vehicle
2015 Challenger SRT 426
#4
Time to deactivate deactivation?
 


EricG

1000 Posts Club
Premium Account
10 Second Best E/T
Member ID
#1385
Messages
1,541
Reactions
3,109
Likes
162
City
Albuquerque
State
NM
Country
United States
Vehicle
'19 Hellcat Redeye
#5
I think he's being sarcastic? Only 5.7 and 6.4s with the A8 have intentional cylinder deactivation.
 


Bobo

2000 Posts Club
HFCOTM
Member ID
#14500
Messages
2,280
Reactions
6,434
Likes
302
City
Fremont
State
OH
Country
United States
Vehicle
2022 Dodge Challenger Super Stock
#6
I think he's being sarcastic? Only 5.7 and 6.4s with the A8 have intentional cylinder deactivation.
I hope that's the case.
 


Slowpoke387

2000 Posts Club
Founding Member
Donating Member
HFCOTM
Member ID
#969
Messages
2,271
Reactions
5,315
Likes
302
City
Somewhere
State
CT
Country
United States
Vehicle
2020 Challenger Hellcat Redeye WB
#7

Magnified

Poster Club Hall of Fame
Founding Member
Member ID
#1155
Messages
11,710
Reactions
19,827
Likes
352
City
West Texas
State
TX
Country
United States
Vehicle
2017 Charger HC (once upon a time)
#8
I personally have never even heard of that before, but I'm not longer into the nuts and bolts of tuning (not for more than 10 years). Don't understand why it would be just 8. And it reactivates immediately with just a key-out and restart cycle?
 


ostmike

Active Member
Vendor
7 Second Best E/T
Member ID
#1481
Messages
129
Reactions
329
Likes
37
City
Portersville
State
PA
Country
United States
Vehicle
2015 Hellcat
#9
I bet you had a "compare" tune opened and then closed it while viewing this table marked "Read Only".
Exit VCMeditor and then open only the tune you want to edit. Do not open a compare file. I have had this same issue happen on other tables that are normally editable and the above was what I had to do.
 


Hunter

8000 Posts Club
Staff Team
Founding Member
Premium Account
U.S. Army Veteran
Donating Member
HFCOTM
Member ID
#957
Messages
8,970
Reactions
23,651
Likes
402
City
Moss Point
State
MS
Country
United States
Vehicle
2019 Challenger Hellcat
HFCOTM
View Images
#10
I think he's being sarcastic? Only 5.7 and 6.4s with the A8 have intentional cylinder deactivation.
My 5.7 had the MDS. My 6.4 did not.
Is the MDS what you are referring to?
 


Unholy707

5000 Posts Club
9 Second Best E/T
HFCOTM
Member ID
#11903
Messages
5,079
Reactions
4,205
Likes
402
City
Orlando
State
FL
Country
United States
Vehicle
2015 Dodge Challenger Hellcat
#11
Is it completely deactivating? Cyl 8 is always an issue in these cars. Pull the plug and check for bad blow by. There’s an oil fill port right in front of Cyl 8. I used to get misfires like crazy and #8 was always off the charts. It was due to a warped whipped 4.5 plenum. Also, I have heard the heads on the older hellcats we’re just thrown on and not well aligned, so supercharger doesn’t sit square. Once I got the FI o ringed spacers it solved all my issues.
 


Unholy707

5000 Posts Club
9 Second Best E/T
HFCOTM
Member ID
#11903
Messages
5,079
Reactions
4,205
Likes
402
City
Orlando
State
FL
Country
United States
Vehicle
2015 Dodge Challenger Hellcat
#12
If you pressurize the crankcase it’s going to come out there and bleed right over to the cylinder. Have personally have it happen. Same if it’s not sealing by the oil fill provision in the head by cyl1, which will pressurize crank case and force oil out of the oil fill provision in the head by cyl 8.
 


Unholy707

5000 Posts Club
9 Second Best E/T
HFCOTM
Member ID
#11903
Messages
5,079
Reactions
4,205
Likes
402
City
Orlando
State
FL
Country
United States
Vehicle
2015 Dodge Challenger Hellcat
#13
Horrible design, considered having mine welded up
 


Unholy707

5000 Posts Club
9 Second Best E/T
HFCOTM
Member ID
#11903
Messages
5,079
Reactions
4,205
Likes
402
City
Orlando
State
FL
Country
United States
Vehicle
2015 Dodge Challenger Hellcat
#14
Also, I believe you can log MDS in your channels to see if it’s activating. If HPT doesn’t have it, I’m pretty sure Alfa does, and you can record as well - it’s not the best at logging, but it will give you info. Even though you don’t have the solenoids. Could be lifter related? My money is on oil shutting down cylinder 8. Just because you have the misfire thresholds maxed doesn’t mean it’s not misfiring
 


EricG

1000 Posts Club
Premium Account
10 Second Best E/T
Member ID
#1385
Messages
1,541
Reactions
3,109
Likes
162
City
Albuquerque
State
NM
Country
United States
Vehicle
'19 Hellcat Redeye
#15
My 5.7 had the MDS. My 6.4 did not.
Is the MDS what you are referring to?

Yes MDS, was your 6.4 a manual? All A8 6.4s have MDS I believe.
 


Unholy707

5000 Posts Club
9 Second Best E/T
HFCOTM
Member ID
#11903
Messages
5,079
Reactions
4,205
Likes
402
City
Orlando
State
FL
Country
United States
Vehicle
2015 Dodge Challenger Hellcat
#16
Idk, my service manual for my 6.2 hellcst says 6.2 supercharged MDS 😅
 


Hunter

8000 Posts Club
Staff Team
Founding Member
Premium Account
U.S. Army Veteran
Donating Member
HFCOTM
Member ID
#957
Messages
8,970
Reactions
23,651
Likes
402
City
Moss Point
State
MS
Country
United States
Vehicle
2019 Challenger Hellcat
HFCOTM
View Images
#17
Yes MDS, was your 6.4 a manual? All A8 6.4s have MDS I believe.
No mine was an A8.
No MDS on the 485 hp 392 hemi.
MDS on the 5.7 though
 


Unholy707

5000 Posts Club
9 Second Best E/T
HFCOTM
Member ID
#11903
Messages
5,079
Reactions
4,205
Likes
402
City
Orlando
State
FL
Country
United States
Vehicle
2015 Dodge Challenger Hellcat
#18
Idk, I removed eco mode from my car so don’t have to worry about it (besides it not actually having kids) lol
 


Slowpoke387

2000 Posts Club
Founding Member
Donating Member
HFCOTM
Member ID
#969
Messages
2,271
Reactions
5,315
Likes
302
City
Somewhere
State
CT
Country
United States
Vehicle
2020 Challenger Hellcat Redeye WB
#19
No mine was an A8.
No MDS on the 485 hp 392 hemi.
MDS on the 5.7 though
My 2015 392 SRT had it. A8. Hated it. Under light acceleration/cruising it would drop a couple of cyls. Heavier accel would wake it up. I think it depended on mode too.
 


Magnified

Poster Club Hall of Fame
Founding Member
Member ID
#1155
Messages
11,710
Reactions
19,827
Likes
352
City
West Texas
State
TX
Country
United States
Vehicle
2017 Charger HC (once upon a time)
#20
Why did you hate it, specifically?

I dont even own one, but the killing the motor for stoplights gets my attention when i have the window down. Disconcerting for me to hear several engines fire up as the light turns green.
 




Top