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WANTED! NAG1 (300C 5-SPEED) EXPERT ON LONG ISLAND, NY

2K views 8 replies 3 participants last post by  markmcbx 
#1 ·
I'm looking for a NAG1 expert on Long Island, NY who can resolve a problem that has shown me that most shops simply don't understand. Keep in mind that when this started happening a couple of months ago, I immediately had the fluid and filter changed. No difference. Adaptive learning has been reset. No difference. No codes set.

Apparently, the torque converter lockout clutch is coming on at the wrong times, BUT ONLY when the car is cold and apparently, it starts with a right-hand turn, which to me would indicate a low fluid issue, but fluid is ok, and once the car warms up, it shifts normally. The Challenger folks have seen this with a bad wheel sensor on AWD, but this is RWD, and that cause is pretty exotic in my understanding.

After reading through the NAG1 service manual, it seems to me that the most relative input to the TCM is the transmission temperature. I believe that the TCM is for some reason, getting an incorrect temperature that is causing this, or there is some other item gone bad in the valve body such as the conductor plate, Park-Drive hall effect sensor TCM temperature input switch, etc. Since no codes are set, I think the temperature value may be "legal", but just wrong. Perhaps the TCM is still getting the engine temperature after going into drive or reverse? I don't trust taking it to a dealer because I might not get the real cause and it will result in a tremendous repair bill.

Each time someone has looked at it, they've come up with a different diagnosis. The last being that the seals on the converter are bad. I'm not convinced of that, especially after the vehicle warms up. My head is spinning.

So, I am simply looking for someone here on Long Island that really knows what they are doing to get to the source of the problem and resolve it. This is a 2011 300C with 150k on the clock. Hopefully someone out there can contact me or point me to a really talented shop.

Thanks very much!!!
 
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#2 ·
I can't help with the actual question. But I'm curious what you mean by "the torque converter lockout clutch is coming on at the wrong times"? In pondering this the big question that I think first needs to be answered is. Is the issue that the computer is commanding lockup at the wrong time, or that the converter is locking without being commanded?

Secondly, it's worth noting that the TCC on these isn't on/off. The computer modulates the TCC based on a series of desired slip parameters. Throttle position, engine rpm and output rpm are key inputs on when and how much TCC lockup the TCM commands.

It appears to me that you have a good understanding and a head to figure it out. But that you lack diagnostic information. Information it's unlikely even the best mechanic will have either. Might I suggest a different next step. Get yourself a HP Tuner, depending on what options you choose it'll cost you between $400 and $650. But it'll give you the ability to monitor, log, and change just abut everything. This includes the issues in your other post about MDS and throttle response. It's an amazing tool, pricey but I think very likely to help you save a lot of mechanic costs with this issue.
 
#3 ·
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I can't help with the actual question. But I'm curious what you mean by "the torque converter lockout clutch is coming on at the wrong times"? In pondering this the big question that I think first needs to be answered is. Is the issue that the computer is commanding lockup at the wrong time, or that the converter is locking without being commanded?

Secondly, it's worth noting that the TCC on these isn't on/off. The computer modulates the TCC based on a series of desired slip parameters. Throttle position, engine rpm and output rpm are key inputs on when and how much TCC lockup the TCM commands.

It appears to me that you have a good understanding and a head to figure it out. But that you lack diagnostic information. Information it's unlikely even the best mechanic will have either. Might I suggest a different next step. Get yourself a HP Tuner, depending on what options you choose it'll cost you between $400 and $650. But it'll give you the ability to monitor, log, and change just abut everything. This includes the issues in your other post about MDS and throttle response. It's an amazing tool, pricey but I think very likely to help you save a lot of mechanic costs with this issue.
Interesting. One of the people who looked at it and drove it, and supposedly ran diagnostics on it told me that the TCM was commanding the lockout clutch to engage at the wrong time. Now, reading your second sentence, I would look to a bad TPS, but the strange part is that once the engine warms up, or perhaps the transmission starts to warm up, the car runs absolutely normal. So throttle position, engine rpm and output rpm don't come to mind as the problem, as it seems to me that they would continue to be issues even once everything warmed up.

I really like your 3rd sentence. Yeah, that's why I gave up on the standard search and solicited on here. The nonsense I'm getting fed out there is ridiculous. The one thing that I figured is this...(and I'm pretty sure you already know this, but I'm just illustrating where I think the problem may be) there is a hall effect reed switch that is activated by the shifter position. When the car is in park, then the TCM gets fed the temperature of the engine. When the shifter is moved out of park into drive or reverse, that switch will engage (or disengage - not sure), to feed the TCM the transmission temperature. Since this problem goes away in about 5-7 minutes I suspect that the TCM is still getting fed the engine temp and shifting the transmission as if it is warmer than it actually is. Since the temp is not out of range, no code is set. Once the transmission temp starts to rise, then it begins to match the parameters for the way the TCM is controlling the shifting. Now, I realize there are speed sensors with hall effect sensors in/on the valve body too, which leads me to another thought... the conductor plate. I saw some youtube videos regarding that and it seems that conductor plates are doomed to fail at some point. So much so, that their replacement seems to be done proactively out in the field in some shops. I also see that many of the Challenger/Charger folks change those. I am not 100% clear on what the conductor plate is, but it seems to be the "circuit board" that connected the computer(s) to the valve body so it gets all the info and so it can do things to modulate the TCC and other items in the transmission.

So, I am wondering if the conductor plate is cracked or otherwise not intact, as that would interfere with temperature, speed in/out telemetry, which I think this problem is centered on.

As to your suggestion on a tuner, right now I have obdwiz and a smart obd connector. That helped me find a bad purge valve, and that's fine, but it's not enough to diagnose this. I guess you have experience with one, so is there one that you can recommend? I know there are a few, but I don't know which is the one that most people are satisfied with.

Again, any thoughts - pointers - help, much appreciated!
 
#5 ·
I hadn't heard of obdwiz before, looks like a good deal. A lot like what I suggest with HP tuner. Have you used the logging features to log temps and TPS? Unfortunately it looks like obdwiz is limited to reading engine parameters so only so much can be done with it. The VCM scanner does all that with the transmission as well.
 
#6 · (Edited)
I will check that out. I watched the video (link below) and that really gave me a good understanding of how this works. It really isn't difficult. Now I see that there isn't any way for the lockout to come on unless the solenoid for it engages. I think if we're keeping the car, and I think we are because of how well we maintained it and how it is setup (bilstein shocks, pirelli tires, rare color combo, etc), the the tuner/diagnostic tool makes sense. At this point, I think it's something to do with the conductor plate, perhaps fluid leakage in the plug, etc. The common issues, not the exotic ones.

Here is the video link. Very informative! (and thank you!)

 
#8 ·
(Thanks markmcbx) Just updating with what it was for others. I found a good shop here who said that it would either be a valve body issue ($900) or a rebuild ($2900). They found the issue in the valve body. It had to be rebuilt. Balance of tranny in very good shape. The lockup clutch solenoid was bad, and the conductor plate was replaced. New fluid & filter. It shifts perfectly (up and downshifts) and the time from reverse to drive, etc., has really improved over what it originally was when new. Very smooth. Had I bought the kit and debugged the solenoid issue, I would have saved several hundred, but it took them 2 days (good considering the amount of cars and trucks they had stacked up) and I didn't have to get all sloppy under the car. Wife is happy and I get my truck back, so I'm happy. 1 year, unlimited mileage warranty. Centereach Transmissions. BTW, owner of the shop really likes the 300C. ;-)
 
#9 ·
Sounds good!
I put a Transgo shift improvement kit in my valve body(which eliminated any slop in the spool valve bores with new inserts and different springs), made a world of difference. Ohmed out all my solenoids while it was apart to make sure all was OK, all checked good, replaced all o-rings on the solenoids upon assembly as they tend to leak after awhile. Conductor plate was replaced while it was apart this far, kept the old one as it is still good.
I can get a 1-2 shift "chirp" upon hard acceleration in sport stick mode, and regular auto mode was like night and day. Would have been nice to put M-B AMG blue top shift solenoids in, but cost @ over $200 apiece is prohibitive and they downshift kind of firm too.
Glad you got your ride sorted out!
 
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