Shut off TCS for a day!

:
Ottawa, Ontario
:
17 Mazda 6 GT
Before having TSB 05-002/20 applied, I would most often and routinely encounter it in turns, especially right turns--brake going into the turn. RPMs drop, then lug as I accelerate out of the turn. Also from a stop at a traffic light where accelerating then letting off the gas when realizing the guy in front is lollygagging, then reaccelerating. In short, 2nd. gear failing to drop to 1st. or 3rd. gear failing to drop to second.

That's in routine driving. In sport mode, or just zoom-zooming around, the RPMs wouldn't drop low enough to get the lug.

This was my #1 issue with the vehicle without a close second. Given the number of posts I've made on the subject you can it is my #1 obsession. The TSB has all but eliminated the lugs even though the TSB description does not address this problem.

My experience seems somewhat unique among normally aspirated 2.5L owners. I think more folks have complained about jolts into gear than lugs and some who have had the TSB applied see no difference. This is hard to account for. Perhaps the TSB is a patch not a re-flash of the entire PCM with different years or AWD vs. FWD having different base code. Or the performance adjustments that are stored don't get cleared out when the software update is applied. Or maybe the dealer blew it off in some cases--they probably don't make any money doing TSBs.

It occurs to me now that if the TSB doesn't yield any difference, maybe disconnecting and reconnecting the battery might do some good--just a wild guess not knowing what the TSB does or the procedure for applying it.
What exactly is this TSB all about, and is it mandatory? When was it issued?
Also, does it apply to all models, or just the CX-5?
Thanks.
 
:
CX5 GT
2.5 non-turbo only.


BULLETIN NOTES
Bulletin No.: 05-002/20 Last Issued: 12/18/2020
This bulletin supersedes the previously issued bulletin(s) listed below: The changes are noted in Red.
Previous TSBs: Date(s) Issued: 05-002/20 09/24/20 and 06/04/20
APPLICABLE MODEL(S)/VINS
2019-2020 Mazda3 (Japan built A/T only) with VINS lower than JM1BP******163205 (produced before January 11, 2020)
2019-2020 Mazda3 (Mexico built A/T only) with VINS lower than 3MZBP******131964 (produced before January 11, 2020)
2018-2020 CX-5 with VINS lower than JM3KF******856447 (produced before July 20, 2020)
NOTE: This TSB only applies to US spec vehicles with cylinder deactivation. Mexico spec vehicles are not applicable since they do not have cylinder deactivation.
DESCRIPTION
Some customers may complain about a surging at low speeds and during acceleration. This surging is in the longitudinal direction, felt about 2 cycles per second, and occurs in the locked up 1st gear. This may be caused by the torque fluctuation and the torsional resonance in the torque converter. To correct this concern, the PCM software has been modified to reduce the torque fluctuation.
 
:
2020 CX5 AWD
OK, so here's a quick unscientific TCS-off test.

Left the house with 3/4 tank with the MPG meter having been reset at the last fill-up. It was reading 28.6 MPG and I left it as is.

Drove 10 miles to Home Depot with TCF off, about 4 miles on surface roads at 40-60 MPH, and about 6 miles on expressway getting up to 70 MPH. The reading dropped to 28.1 on that leg. That's with one stop sign and three traffic light stops

On the return trip. with TCF on. I took all surface roads with four stops for lights, about 1/2 the distance at 40-45 MPH and 1/2 at 55-60 MPH, again not resetting the MPG meter. The reading went up to 28.3 MPG as I arrived home.

In my case this suggests (1) the same or worse MPGs with TCF off or (2) the MPG meter is unreliable over short runs which I would not rule out.

I detected no difference in the car's feel or handling with TCF off on this dry day but I was not driving aggressively so how it handles ripping a turn would be a test for another day.

I won't draw any firm conclusions unless and until I run a couple of tanks following the procedure in post #17 above. I've got a rain/snow mix in the near-term forecast so that might not happen for quite a while.
you changed the baseline by using two different routes..
 

HardRightEdg

US 2020 CX-5 Touring AWD Soul Red
you changed the baseline by using two different routes..
Right. I said it was unscientific. But it wasn't some slight of hand. The left turn to get on the expressway going home is dangerous unless traffic is very light so I often take the surface roads at the expense of 5 minutes.

Did you note what my changes were going and coming? Expressway with one fewer stops at lights should have yielded the same or higher MPGs but I got the opposite.
 
Last edited:

HardRightEdg

US 2020 CX-5 Touring AWD Soul Red
2.5 non-turbo only.


BULLETIN NOTES
Bulletin No.: 05-002/20 Last Issued: 12/18/2020
This bulletin supersedes the previously issued bulletin(s) listed below: The changes are noted in Red.
Previous TSBs: Date(s) Issued: 05-002/20 09/24/20 and 06/04/20
APPLICABLE MODEL(S)/VINS
2019-2020 Mazda3 (Japan built A/T only) with VINS lower than JM1BP******163205 (produced before January 11, 2020)
2019-2020 Mazda3 (Mexico built A/T only) with VINS lower than 3MZBP******131964 (produced before January 11, 2020)
2018-2020 CX-5 with VINS lower than JM3KF******856447 (produced before July 20, 2020)
NOTE: This TSB only applies to US spec vehicles with cylinder deactivation. Mexico spec vehicles are not applicable since they do not have cylinder deactivation.
DESCRIPTION
Some customers may complain about a surging at low speeds and during acceleration. This surging is in the longitudinal direction, felt about 2 cycles per second, and occurs in the locked up 1st gear. This may be caused by the torque fluctuation and the torsional resonance in the torque converter. To correct this concern, the PCM software has been modified to reduce the torque fluctuation.
That's the one. I had this TSB applied even though my issue was lugging. I figured it couldn't hurt. It's the only TSB I could find or have seen posted that addresses unpleasant transmission behavior. The TSB got rid of about 95% of the lugs. Oddly enough, Pre-TSB I had encountered the double bump in 1st. described in the TSB only once. Now I get it occasionally when leaving my driveway at a crawl. I also now get little bumps into gear when upshifting, more noticeable than pre-TSB, but not unpleasant. Net-net, I'm happy where I'm at now.
 
Last edited:
:
CX5 GT
The CD-issue TSB from 2019 fixed most of the 'lugging'and it was prior this TSB.

Depending when you had this TSB applied you may actually have even newer PCM calibration file as after this TSB above there is another newer PCM version from early 2021 but for another issue.
When the PCM is updated it always goes to the latest version available by Mazda at the time of the update. Only way to verify which you have is to connect to the OBD with a tool that shows the version on the PCM, not that it matters much.

That was back in June when I was checking the PCM updates available. Today there may even be a newer version. Each newer version has the fixes from the prior ones.
 

HardRightEdg

US 2020 CX-5 Touring AWD Soul Red
The CD-issue TSB from 2019 fixed most of the 'lugging' and it was prior this TSB.

Depending when you had this TSB applied you may actually have even newer PCM calibration file as after this TSB above there is another newer PCM version from early 2021 but for another issue.
When the PCM is updated it always goes to the latest version available by Mazda at the time of the update. Only way to verify which you have is to connect to the OBD with a tool that shows the version on the PCM, not that it matters much.

That was back in June when I was checking the PCM updates available. Today there may even be a newer version. Each newer version has the fixes from the prior ones.
In referring to the 2019 CD-issue TSB do you mean the stalling recall? That fix was for 2018-2019 models with CD. My 2020 with CD lugged quite a bit.

In looking through the TSB list once again for the 2020 model year, I find nothing under the engine / power train categories that addresses unpleasant shifting except the TSB you quoted in post #43 which I had applied in June 2021. That went a long way in eliminating lugging in my vehicle as mentioned earlier.


You mention a new PCM version released in early 2021 to fix another issue. I'm not seeing any 2021 TSBs for the 2020 model year related to shifting and none that jump out as requiring a PCM update. Also, there are no recalls for the 2020 model year.

Do you have some reference to that new PCM version released in 2021? Did it apply to 2020 models? I'm curious to know if that might have fixed my lugging issue, along for the ride when I had the post #47 TSB applied.
 
Last edited:
:
CX5 GT
these free sites are not listing everything.

01-004/21 from april 30 2021.
yes applies to 2018-2020 and early 2021 cx5 with CD only. doesnt seem to apply for the turbo.
its for another issue as mentioned but is the latest update ver. file for the PCM on thay date.
 

HardRightEdg

US 2020 CX-5 Touring AWD Soul Red
these free sites are not listing everything.

01-004/21 from april 30 2021.
yes applies to 2018-2020 and early 2021 cx5 with CD only. doesnt seem to apply for the turbo.
its for another issue as mentioned but is the latest update ver. file for the PCM on thay date.
This TSB is listed in the free site I linked but the incomplete info had nothing to suggest PCM reprogramming and the problem being fixed is unrelated to shifting issues.

You are correct per the following complete TCB that there was a PCM update and it applies only to CD non-turbo versions:


I found that full description link in another thread. I don't know how that poster laid his hands it.

So, when I walked into the dealer in June 2021 complaining of lugging with a print out of the TSB from 12/18/20 referenced in your post #47, perhaps the actual fix was not related to that TSB at all but instead in the 4/30/21 PCM code changes.

That's a strong possibility. But it would be bizarre. I see no TCBs identifying consumer complaints about lugging in 2020 models while I'm not alone in having this issue. The earlier TCB is the one and only that references a shifting issue. A 4/30/21 fix to lugging then becomes a secret fix to a problem unacknowledged by Mazda. It makes one wonder whether the lugging fix is in fact a secret or just a happy accident, an unintended happy byproduct of PCM updates fixing other problems.

Either way, this is not good for owners less fortunate than myself. I had a very accommodating dealer. I didn't even purchase the vehicle from them. I complained of lugging, the TCB I referenced was for the bump-bump 1st. gear lockup issue, but they went ahead and updated the PCM anyway. They put 6 miles on it in testing before and after per the write-up, though I cannot imagine the tech actually reproduced the issue identified in the TSB since I encountered it once in a year of ownership. I can imagine other owners complaining of lugging may not be so fortunate. Based on two experiences with this dealer they appear to operate under the rare philosophy that bend over backwards service sells the next car. Go figure.

In one of the several threads on this and related issues, a guy said his dealer charged him $200 to apply the PCM update though he was under warranty. That might have been one of those instances of a dealer saying, "we'll do it at your cost because it is not an identified problem with an identified fix."
 
Last edited:
:
CX5 GT
pcm version updates are cumulative.
The one from April contains the prior fix for the lugging (as well as all other other updates) but it may also contain any other interim code changes not publicly advertised. What exaclty only Mazda Japan knows.
Whats ironic is that all these pcm updates are primarily for the Cylinder Deactivation models.
 
:
2017 Mazda 6 Sport
We're talking about the 'this trip' mpg reading on the main screen, not the avg vehicle mpg.
My commute last night with TCS on this time avg'd 32.9 mpg, so the mileage increase is holding (I had never seen over 30mpg). I'm guessing that this has to do with the PCM programming adjusting/resetting after running with TCS off (kind of like the effects of doing a couple of Italian tune-ups)
33.6 mpg on the commute home tonight with TCS off (12 miles with lots of lights). That beats the 32.9 I got in the post above
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Whats ironic is that all these pcm updates are primarily for the Cylinder Deactivation models.
Not surprised. Cylinder deactivation is a complicated system and many components got redesigned and modified including transmission and exhaust system. And too many TSBs and a recall have been issued so far for the 2.5L with cylinder deactivation.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
33.6 mpg on the commute home tonight with TCS off (12 miles with lots of lights). That beats the 32.9 I got in the post above
I finally had a chance to drive our CX-5 this morning for the 3rd 4-wheel alignment at Brakes Plus. It’s the coldest temperature so far since summer at 37°F at 8:00 AM but I had to go early as wife needed the car later in the morning.

I drove away for a minute then I remembered I should press the “TCS Off” button. Once pressed, I could tell the car definitely felt peppier like wife told me. Then I checked the Avg MPG display, it said 26.8 MPG. This’s the best MPG rating I’ve seen by the computer for daily driving as usually it’s 24.x. I’ll see how many miles I can drive for this tank of gas, usually the low fuel light is on at 300 ~ 320 miles after the fill-up.

Just need to remember to press the “TCS Off” button.
 

HardRightEdg

US 2020 CX-5 Touring AWD Soul Red
pcm version updates are cumulative.
The one from April contains the prior fix for the lugging (as well as all other other updates) but it may also contain any other interim code changes not publicly advertised. What exaclty only Mazda Japan knows.
Whats ironic is that all these pcm updates are primarily for the Cylinder Deactivation models.
What prior fix for lugging? There is no TSB that addresses that. That was the concluding point of my last post.

I took a shot in the dark that the December 2020 TSB might fix lugging even though it was all about surging, something entirely different. I told the service writer I had a lugging problem but hoped this TSB might fix it since it is the only one that addresses shifting issues. I mentioned the fact that I had experienced the surging problem only once, which was true, but not the issue I was looking to get fixed.

There's no way of knowing if the lugging fix was in fact addressed in the TSB from December 2020 that addresses surging, not lugging, or whether it was slipped in subsequently and included in the April 2021 update. In fact, for all I know it could have been in any PCM update between the time my vehicle rolled off the line and when I had the PCM updated in June 2021.

I consider myself fortunate that a dealer would update my PCM for free under the auspices of a TSB that does not address the problem I presented. The receipt states, "Tech verified concern and found TSB pertaining to concern." I seriously doubt he experienced surging, a very rare occurrence in my experience, but he in all likelihood did find it lugging when he made a right turn out of the lot to test it. Again, there are no TSBs that address lugging.

The first moral of the study is this was a case of a fix for a problem that Mazda has not acknowledged. Again, maybe they fixed it as an accidental byproduct of other PCM updates.

The second moral of the story is if an owner under warranty has some shifting or engine performance issue not addressed in any TSB, he might try finding some pretext for getting the PCM up to date.
 
Last edited:

HardRightEdg

US 2020 CX-5 Touring AWD Soul Red
Not surprised. Cylinder deactivation is a complicated system and many components got redesigned and modified including transmission and exhaust system. And too many TSBs and a recall have been issued so far for the 2.5L with cylinder deactivation.
No doubt. Complex systems are hard enough to get right at out of the box. When you start laying patch upon patch, software together with hardware modifications, unexpected things can happen. We used to call it spaghetti code in my prior life when so many modifications had been done it was extremely difficult to work in an update without breaking something else. However, barring a complete rewrite, persistence over time can get you to a point where the number and severity of issues that remain are narrowed to acceptability or better.

This illustrates why I avoid buying vehicles until at least the 3rd. year of a generation or new powertrain with CD qualifying as such. Fewer problems, longer runway to work them out.

I'm pretty happy now at 15 months and 12,000 miles with my only pet peeve 95% resolved. Cylinder deactivation or not, no matter, I regard my version in its current state to be a lot of bang for the buck.
 
Last edited:
:
CX5 GT
my bad then, I thought that the lugging and surging were kind of the same issue that we all know the car has with the shifting.
I dont have the fix done (my 3/36 warranty has expired anyway) so I cannot comment on real live experience with the car and the TSB fix for surging.
Most of my surging was fixed after the CD update but again mine is 2018 with Denso PCM.
Was thinking of applying the latest PCM update myself but with the TCS discovery I am happy overall so no updating for me for now.
Its like a different car now :) just have to not forget to turn the TCS off or find a way to turn it off upon start automatically.
 
Last edited:

BWJ

:
CX5 Optimum 2020
It's just a shame, that lane keep assist does not work when TCS is turned off.
But luckily stop n go with radar assistant still works´.
 

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Was thinking of applying the latest PCM update myself but with the TCS discovery I am happy overall so no updating for me for now.
Its like a different car now :)
Yes, indeed! With TCS off, I have exactly the same feeling on my 2016 CX-5 AWD! It’s that much difference on engine response even my wife can tell! Although the transmission of ours has no issues may be that’s because our CX-5 doesn’t have cylinder deactivation.


just have to not forget to turn the TCS off or find a way to turn it off upon start automatically.
This may be difficult to do as the control may be reside in the PCM programming. We just have to put a sticker to remind driver pressing the “TCS OFF” button when the road condition is fine.

From 2021 Mazda CX-5 Owner’s Manual:
NOTE

• If the TCS is off when the engine is turned off, it automatically activates when the ignition is switched ON.