dwchapmanjr

Got a ciphon tool at Autozone and drained it. No the solo cups aren't the permanent storage for them. Going to properly dispose at local auto parts store. Left it a bit above full as I'm not sure it was completely cold. I'll check it again in the morning. It wasn't on a level surface either but much better.

I did a bit more driving and research and its a bit interesting/confusing. The "Front" goes to the radiator. i'm assuming the radiator has a pressure switch in there to shoot excess into the tank. The "Rear" goes to the water pump which I imagine has a similar high pressure switch for the same. Where it gets really interesting is the CAP has a pressure switch on it too which seems to relieve pressure from the front chamber into another chamber. Seems like this reservoir is both an extension of the radiator and a reservoir with multiple chambers. It of course has a bottom hose that T's into the water pump's hose going to the lower part of the radiator. this is presumably where the vacuum sucks back in fluid when it cools. I believe its been sufficiently driven to burp any air. I even drove around with heat on high even-though I don't believe it has a heater core valve. The heater core tubes seem to go directly into the engine and I can't imagine there is a valve in the block.

I was at the dealer the other day getting a tire replaced and I noticed I needed a coolant flush as its been 5 years and no previous one. When I got home I checked the reservoir and it was grossly overfilled. I doubt there's room for 7oz of expansion in it. I know sometimes this happens because it needs to burp out some air so I've driven it a couple of times but it hasn't gone down yet. I've got one of these coming tomorrow to suck the excess out if it hasn't gone down tomorrow but wondering if anyone knows about burping these or how to remove air. There doesn't appear to be a radiator cap which is likely why the reserve tank is pressurized. https://www.amazon.com/gp/product/B07CP8R9MS Since these are pressurized reservoirs, it seems that a grossly overfilled can cause damage as there's nowhere for the pressure to go except the weakest link which is likely a hose or fitting. My question is do these heater cores have a valve or is coolant running to them constantly? It is dead summer and I want to avoid heat on full to see if it clears out if I can. Also judging by design, it seems like it would naturally burp itself fairly quickly. Before the flush my needle almost always stayed constant at 210 when warmed up, now it seems to fluctuate between the 197.5 mark and 210 which leads me to think either there's still air in there or the overfill is causing excessive pressure that is altering the temp.

I brought mine to the dealer Monday. They couldn't find anything wrong and recommended a road force balance. Interesting thing when I pulled out of the dealership and got onto the highway. Hard pull to the left. I didn't have time to turn around. Figured it was an alignment issue. Brought it to a local shop to check alignment and any ESCM calibrations. They said alignment was perfect and calibration was on the latest. Dealer must have updated the calibration when doing the other shock. They road forced it again and rotated and the pull went away. I'm fairly sure I have what's called Tire Conicity. The pull started immediately after the first rotation of these new tires. I'll be calling the dealer to see if I can get that tire replaced under warranty. Thought I'd share since I never heard of conicity before. https://artsautomotive.com/home/art-icles/shop-articles/hunter-gsp9700-road-force-balancer/

I took it in and they did not seem to find anything so I took it in with the calibration sheet but I'm not sure they did anything with it. I asked the service advisor about the calibrations and either the vehicle didn't need it or they didn't check so I may check with another local shop to see if they can check the calibration. They did a road force balance upon my request and it seems a bit better but the alignment is off. Could be from doing the front shock. It was noticeably worse after the rotation and balance though which may point to an issue. I'll go in for an alignment this week or next and see if they can check the calibration ID on the suspension module since I'm not confident the dealer did.

Yes, get an MDI or MDI 2 and then buy the necessary subscription for your needs. If you just need to load a calibration its $40. If you need to do diagnostics they have plans that start at 3 days for relatively nothing. The cost barrier to entry is obtaining an MDI / MDI 2. They have clones but I don't know that I'd trust programming on one. MDI too seems to cost around $900 for an authentic one. http://www.acdelcotds.com/

I'm wondering if anyone has had luck going to the dealer and getting a new calibration. There seems to be one specific to address this and mine likely doesn't have it since I've never had a ESCM calibration loaded. Second one from bottom. Note the most recent one is the top so there have been quite a few revisions. Took a bit of research to find out these are not sequential. Going to ask the dealer to try to load this and possibly a road force balance and diagnostic. Thought I'd share https://tis2web.service.gm.com

I think I may have found the answer. Previously I went into "Operating system" but going into "Real Time Dampening" it shows what seems to be the progression and they are indeed not sequential My scan tool won't tell me the calibration ID but my guess is I have 2343983 due to the MFG date and no other suspension programming being done on it.

I'm looking, haven't found it yet but the dealer has been great so I'm likely to keep going for some of the more advanced stuff. I would love to find a local shop that can though and support a local business. I don't mind paying a premium for it by going to the dealer though, my issue with them is they're a bit of a hike. Not to be argumentative but my guess is since this is a 2015i and going by my service records my guess is I don't have any of the calibrations other than the original released one since any new calibration hasn't been loaded for this to my knowledge. So my confusion on this was the TIS site (which anyone can go to, lists them all and the one I marked "current" in the picture is the latest one but they're not numerically sequential but do seem to be listed from most recent to oldest (top to bottom) as the top one is the one TIS is saying is the current one that will be released/programmed.

I was looking at calibrations for my 2015 GMC Yukon Denali's ESCM (Z95) and noticed there's a listing but the calibration ID's are not sequential and the latest one it recommends is a lower numerical value than the one that may fix an issue I have. Is this normal? Any explanation for the ordering? I posted this in the K2XX forum but this one appears more appropriate so sorry for the spam. I believe I have the original calibration and think 23452750 may fix my issue. Does the "current"/top one include all the fixes in the below or are they all different and you pick the one that addresses your issue? I won't be applying this, likely taking to the dealer and just want to be informed.

Anyone familiar with GM Calibrations and their numbering? I'm having some rough ride issues on my 2015 GMC Yukon Denali w/Z95 and looked up the calibrations and there appears to be one that may address my issue. But I also noticed the calibration history on TIS doesn't seem sequential and the "current" calibration offered is not sequentially higher than the one to "reduce suspension shake" Are the numbers usually somewhat random like this or did they revert to an old calibration due to issues with the higher sequential numbered ones? TIS Site for those not familiar - https://tis2web.service.gm.com/tis2web/

@page1 - Thanks! I saw similar although I had no codes, my ride height voltages seemed normal and fairly symmetrical. My command current (mA) seemed normal for what I would suspect. I drove around for a while but didn't see much stick out while reproducing it although 1 strut or the other would randomly jump up to 1900-2000 mA. The rears seem to stay around the 200's for most of the driving and but the fronts jump all over the place likely taking the brunt of the shocks.

I did the trim and no dice yet but I'm starting to think it may be a tire or balance issue at this point. I'll stop spamming here until I find a resolution (if I do). I could just be expecting too much out of the truck or have terrible roads near me. Seems to happen more at 60mph or so than 30-40.

jmac - I scanned mine and mine are fairly close to yours, 1.77 rears and 2.6 and 2.4 fronts.

I imagine the ride height is whatever it is. What matters is that it adjusts tot he up and down while you drive so the shock signal is sent accordingly

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@Russ Swift If you're curious about what the inside of the rear shocks looks like I posted some pics at the end of this blog - https://blog.woohoosvcs.com/2020/07/gmt-k2xx-magnetic-ride-control-shock-inspection/ Pretty neat. They have to be leaking for a while to start to break through the air bladder and show visible signs.

I ended up getting two OE replacements off Rock Auto for about $310 a piece and paid a mobile mechanic to install. Here's a pic of how bad they were, looked worse after they were removed. https://imgur.com/a/SX5uu8f Compared to the new ones https://imgur.com/a/LNSOOeF

@Russ Swift - Crazy. I don't have any issues like that. My drive is just a little rougher than expected lately. I did find some OEM replacements for the rear and they seem economical compared to dealer price $310ish. I'm just curious if a non dealer can properly diagnose them since they're so complicated. Dealer charged me $900 for the failed front one. I may have them check the rears next time I go in although in these times you always worry they're hurting for business and may recommend it a bit earlier than necessary.

I have a 2015 GMC Yukon Denali @ 36k miles. It was Magnetic Ride Control. About 6 months ago dealer indicated my right front strut was leaking and I found out quickly how much it is to replace one! Driving the truck now on highway it has felt like possibly the shocks are not working so I took a look at the rears and noticed some moisture around one and debris on another. Not sure if this is normal or indicative of a failure. Anyone had one fail and see what it looks like? https://imgur.com/a/SX5uu8f

I'd be interested to know too. I mean, each case/issue can be unique but there is definitely a TCC/fluid issue that's known. My 2004 Canyon BPPS did go out a few times and was recalled 1-2 times. While it was less sophisticated, it only resulted in the break lights not working and cruise control being disabled but I could see where a pulsating signal may cause some issues. If this didn't fix the issue, since Boomer727 is in the metro area, I'd recommend Mack Haik Chevrolet. They did my last fluid flush and that seems to have fixed it for now. Its only been about 10 months though. Not sure what the cost would be out of warranty though. I still have about 9 months left on my powertrane warranty.

I'm about 7 months out. It had that "caddy" ride for about a month but back to factory normal now. Sometimes clunky shifts, etc but what I would expect from a truck transmission so no complaints. I noticed AFM stays engaged more even under slight pedal press so they modified the sensitivity on that with new programming so it has a slight vibration at even lower RPMs like 1100 if you have some slight acceleration which is what I think they were trying to avoid with the TCC pulsation to begin with.

I'm about 5 months out without any issues although it took a year or two last time for it to crop up again. What I have noticed it is shifted like brand new for about a month but back to the occasional clunky shifts (which is fine, its a truck). The interesting thing is I notice with AFM on, I get a slight vibration when slightly riding the gas at low acceleration at about 200 rpm lower than the shudder. What I think this is, is the shudder was them pulsating the TCC to avoid the V4 shudder and this is just the V4 shudder happening like you'd get with a stick shift 4 cylinder in too high of a gear to accelerate. I'm not concerned about it because it doesn't feel like something is generating friction that is going to wear a part but it was an interesting observation.

Not sure on price as all of mine have been no charge but I'd feel better taking it to a transmission shop first and seeing if they've done any before over a general repair shop. Its a special fluid that only dealers may be able to get(maybe not) with a special procedure and tool kit. It is also possible you may have to do this flush a couple of times to diagnose needing a new TC. I want to say I saw the price of the new TC they put in mine and it was only about $350 but not sure what labor would be on top of that.