[Prestone]

I turned off MDS with my trinity tuner and all was well on my drive to work. I started the car with the remote start and when i got out there the cel was on. The car ran fine all the way home. So I get home and read the codes and it was something about a knock sensor bank 2 ? Is this related to me turning of mds ? I cleared the codes and turned mds back on, and I have yet to take it for a spin to see if that fixed the problem. I guess my question is, has anybody else that has turned of mds got a check engine light ? any info will be greatly appreciated.

 

[Evolv0]

hmm did you also get a power tune with that tuner? and if so, did you upload both the tune and the mds shut off at the same time?

 

[Prestone]

Well I got the tuner from hemifever about 5 months ago. I installed the tune that Sean gave me for the 89 octane. Ran beauifully for about 4 months. Then over the last couple of weeks I have been noticing when cruisng around 40 mph the jeep feels like its feels kinda like its in the wrong gear. So I contacted Sean at hemifever to see of he could tune for that and of course he said no, but he also asked me to see if it does it with mds off. So you can modify the "canned tunes" or modify the custom tunes and one of the parameters is turning of mds. So essentially I'm running Sean's 89 tune with modification of mds off. I drove around with the 89 tune and mds back on today and it did not trip a mil/cel .So I will monitor it over the next couple of weeks see if the light comes back on. I wish some ones would chime in that has disabled mds on their wk2. I'm hoping the check engine light is not connected to me turning of mds, because i still would like to do that, but I guess only time will tell.

 

[LTrainGC]

I'm going to bump this thread and add my experience (sorry for the long read in advance):

I also got the same code when I would run any tune (a canned tune or Sean's 93 tune) which had MDS turned off in the parameters. The code would trip whenever I got on the throttle a bit aggressively. The code was P0330 for knock sensor bank 2 circuit. I double checked the wiring to the passenger side knock sensor, and even replaced the knock sensor. If I drove normal for three to four drive cycles it would clear itself, or I could clear it through the tuner.

Also, when the MDS was turned off via the tuner it drove as if MDS was still activated - I could feel it drop into 4 cylinder mode when cruising and when I gave it light throttle it would lug in 4 cylinder mode until I gave it enough throttle for it to kick the other 4 cylinders on. This happened with both canned tunes with MDS off and Sean's tune which came with MDS off - and Diablosport looked at the tunes and confirmed MDS was off in both of them. To circumvent this, I drove around with the electronic range selector set to "6" as MDS would not activate unless the gear selector was in "D".

I did some data logging and noticed that when I was stock the knock sensors were giving out normal voltage readings and were registering some short-term knock. But, when I loaded any tune which had MDS off the knock sensors did not produce any voltage readings (read 0.0v the entire logging period) and showed no short-term knock - basically it appears that they were not working properly when a tune was loaded with MDS disabled.

I wish I would have done the data logging earlier. I'm not pointing a finger at DS, but I had to have my driver side cylinder head replaced last week (performed under warranty so no cost to me). My dealer said that the head cracked from what looked to be severe detonation, and that one of the rocker shafts had broken and the other was cracked (each head has 2 rocker shafts).

Don't get me wrong I'm not definitively saying that the tuner issue caused the detonation issues - but the fact that the knock sensors were not giving readings when a tune was loaded that had MDS off leads me to believe that the engine never retarded timing when it sensed knock.

My Jeep is back up and running great again, and there were PCM, DTCM, and ABS module updates available that the dealer applied as well - and now my PCM is 6817042AC instead of the previous version I was running (AB). Later this week I am going to try reloading a tune that disables MDS and see if I get data from the knock sensors.

 

[Evolv0]

Wow, thanks for reporting in... Honestly I probably wouldn't have even bothered putting any of those tunes back on.

 

[LTrainGC]

By the time I realized that the knock sensors weren't giving readings at all when a tune that had MDS was disabled was installed I think it was too late. I'm not overly upset because everything was fixed under warranty, and like I said I can't say with 100% certainty that the tuner was the cause.

I just think its really weird because there are plenty of other guys out there that haven't had a single issue with their Trinity/inTune and they are running around with MDS disabled. Not sure if maybe the old revision of my PCM was part of the issue as well.

I don't want to deter anyone from getting a tuner or custom tunes from Sean because it really woke the engine up. Just want to provide a "cautionary tale" to make sure things are working as they should when you're running a custom tune.

 

[Prestone]

My jeep is showing all the exact same symptoms as your was, but I had no issue running Sean's 93 tune ( granted I only ran it 1 tank) . My issue is only when I ran Sean's 89 tune with mds off. Needless to say I have not tried to turn off mds since. But like you said there is plenty of people with mds off and no issues. What are we doing differently? . Dealer never mentioned you having a tunner before they performed the warrantied work? keep us updated on what you find. Is your jeep still lugging at low speeds? I really notice mine at 40 mph. I really have to give a nice amount of throttle imput to get it to go.

 

[LTrainGC]

My jeep is showing all the exact same symptoms as your was, but I had no issue running Sean's 93 tune ( granted I only ran it 1 tank) . My issue is only when I ran Sean's 89 tune with mds off. Needless to say I have not tried to turn off mds since. But like you said there is plenty of people with mds off and no issues. What are we doing differently? . Dealer never mentioned you having a tunner before they performed the warrantied work? keep us updated on what you find. Is your jeep still lugging at low speeds? I really notice mine at 40 mph. I really have to give a nice amount of throttle imput to get it to go.

What CalID do you have? You can find it by either looking at your xml file, or on the tuner itself in the vehicle info section. My old CalID (basically the PCM software revision) was 68170423AB, but after I had my Jeep in for the work they said there was an update for the PCM and now it is 68170423AC. I haven't tried installing a tune with MDS off (or any tune for that matter) again to see if I'm getting the same problems from my knock sensor so I'm not even sure if that issue is fixed yet. To really check if you're having the same type of problem log the knock sensor volts with a tune that has MDS on and one that has MDS off - if you get readings when MDS is on and none MDS is off then I'd guess we are having the same issue and it would be interesting if we both have the AB PCM revision.

To answer your other questions: the dealer never asked me about having a tune installed. I had the car towed to the dealer on a Sunday morning (they were closed) and they called Tuesday morning telling me they had found after tearing down the top end, and I picked it up on Saturday. In addition to replacing the head they updated my PCM, the DTCM, and my ABS module and it is driving much better now than it did before I first tuned it with the inTune.

 

[Raptor]

What CalID do you have? You can find it by either looking at your xml file, or on the tuner itself in the vehicle info section. My old CalID (basically the PCM software revision) was 68170423AB, but after I had my Jeep in for the work they said there was an update for the PCM and now it is 68170423AC. I haven't tried installing a tune with MDS off (or any tune for that matter) again to see if I'm getting the same problems from my knock sensor so I'm not even sure if that issue is fixed yet. To really check if you're having the same type of problem log the knock sensor volts with a tune that has MDS on and one that has MDS off - if you get readings when MDS is on and none MDS is off then I'd guess we are having the same issue and it would be interesting if we both have the AB PCM revision.

To answer your other questions: the dealer never asked me about having a tune installed. I had the car towed to the dealer on a Sunday morning (they were closed) and they called Tuesday morning telling me they had found after tearing down the top end, and I picked it up on Saturday. In addition to replacing the head they updated my PCM, the DTCM, and my ABS module and it is driving much better now than it did before I first tuned it with the inTune.

Is it driving much better now because they reflashed those modules? Especially the PCM to newer OEM parameters not the Diablosport tuned parameters?

What do you think caused your issues?
The Hemifever tune?
Faulty OEM knock sensors?
Faulty OEM PCM or it's code?

Have you tried loading a tune and running with your tranny in "6" instead of "D" to disable the MDS while still allowing the knock sensors to do what they were designed to do?

 

[LTrainGC]

Is it driving much better now because they reflashed those modules? Especially the PCM to newer OEM parameters not the Diablosport tuned parameters?

What do you think caused your issues?
The Hemifever tune?
Faulty OEM knock sensors?
Faulty OEM PCM or it's code?

Have you tried loading a tune and running with your tranny in "6" instead of "D" to disable the MDS while still allowing the knock sensors to do what they were designed to do?

It is driving better now than it was when I was stock originally (before I ever loaded a tune in the first place). Shifting is in general smoother (up and down shifting), and it firmed up my 2-3 shift which would have a slight delay previously. This is the TSB which was applied: http://www.wk2jeeps.com/tsb/tsb_wk2_1802713.pdf

I also had the ABS module updated and this DTCM TSB applied: http://www.wk2jeeps.com/tsb/tsb_wk2_2100313.pdf

My OEM knock sensors were/are fine, even though I replaced the passenger side sensor. The OEM PCM was fine as well as the Jeep had no driveability issues prior to ever installing a tune. It didn't matter what tune I loaded (Hemifever, Diablosport, or even modify stock tune), as long as MDS was turned off via the tuner the PCM was not picking up any readings from the knock sensors. Also, I am 100% sure that MDS still engaged. Driveability was not affected except for the P0330 code that would pop when I would get aggressive with the throttle (i.e. passing on a two-lane highway, merging onto the interstate), but it never missed a beat or hesitated. That code is related to the passenger side knock sensor circuit, but all of the wiring checked out. My guess is that the PCM never retarded timing because it never sensed knock. I developed an intermittent light tapping which followed engine RPM, which progressively worsened and became more consistent to a point that I stopped driving it and subsequently had it towed to the dealer.

And yes, once I determined that the knock sensors weren't operating properly when I had a tune loaded with MDS off, I went back to stock and would just use "6" to keep MDS off. I have not loaded a tune again since I got the Jeep back - but I am planning to load one this weekend with MDS off and log it idling sitting in my garage to see if I get a reading from the knock sensors. If I do, my guess is the old revision of the PCM (68170423AB) has an issue with trying to load tunes with MDS disabled.

The very first time I got the P0330 I wish I would have dug farther as to why I was getting it. I drove it for probably a month on the Hemifever tune with MDS off (which means that the PCM never sensed knock during that time) but it was driving great and I didn't get any other CEL's. However I could have had any tune loaded with MDS and had the same results - the problem wasn't localized to just Sean's tunes. Even when I developed the light tapping that turned horrid it never threw a CEL. Once the dealer got it they said there was a misfire on cylinder #5 and #7 which they diagnosed down to a broken rocker shaft, the other rocker shaft being cracked, and damage to the cylinder head that was bad enough to require replacement.