2018 CX-5 Low Speed Transmission Hesitation/Jerk/Lurch

sskali did give an update in this thread, post #131:
Hi All. Its been a long time since I first started this thread. Just wanted to update regarding the lurching/ jerking nature. I feel that the transmission is fine and is doing what it is supposed to do. To make sure that the transmission is not causing the issue, I put my car in manual mode at around 40 mph and slowed down to a complete halt at a stop sign. The transmission automatically downshifts in manual mode when there is no user input. I noticed the shifts were smooth with no jumps.

After lot of thinking, I was able to come up with replicating the issue. It basically happens during engine braking. When you let go off the throttle, after a couple of seconds you can start feeling the engine braking happen. At this point when you apply slight dab on the throttle, you can feel the car jerk or rather make a clicking noise. My thinking is that jerk or clicking noise is coming from the opening / closing of the throttle valve.

So in my opinion the transmission is ok. It might be due to how the throttle valve opens and closes.

Thanks.
 
Guys, I was given the attached TSB from another member in this forum.

My car was made in Nov 2020 in Japan and I live in NZ. Hard to tell whether mine is applicable but still a good knowledge to know nevertheless.

I did find this YouTube vid below explaining how Mazda introduced a clutch on their automatic tranny, so this may have contributed to it as well?
 

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Guys, I was given the attached TSB from another member in this forum.

My car was made in Nov 2020 in Japan and I live in NZ. Hard to tell whether mine is applicable but still a good knowledge to know nevertheless.

I did find this YouTube vid below explaining how Mazda introduced a clutch on their automatic tranny, so this may have contributed to it as well?
So another problem related to cylinder deactivation?

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.
 
Just picked up a 2018 CX-5 FWD 2.5 Touring for my daughter. It had been a while since I owned a FWD vehicle, but I assumed they would be much better at this point with low speed torque steer and jerkiness. The problem(s) described here with regard to the jerkiness at low speed in parking lots, especially turning, is definitely affecting our vehicle. It is really annoying. It does very much act like trying to slow roll in a standard transmission vehicle without using the clutch, especially when turning... so I'm guessing it's the torque converter and ECU? This thread was the first thing that popped up in my search, but I also noticed a few posts about the newer models as well, and this one automotive professional newletter caught my eye describing the issue on 2019 and 2020 models and that a PCM update is the fix. Makes me think it could easily be smoothed out with tuning, but I don't know anyone tuning for just this (usually performance tunes for turbo cars).

"Some owners of 2019-2020 Mazda3 and CX-5 vehicles 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.

Reprogram the PCM using the Mazda Diagnostic and Repair Software (MDARS), refer to MDARS ECU reprogramming procedures."

 
Just picked up a 2018 CX-5 FWD 2.5 Touring for my daughter. It had been a while since I owned a FWD vehicle, but I assumed they would be much better at this point with low speed torque steer and jerkiness. The problem(s) described here with regard to the jerkiness at low speed in parking lots, especially turning, is definitely affecting our vehicle. It is really annoying. It does very much act like trying to slow roll in a standard transmission vehicle without using the clutch, especially when turning... so I'm guessing it's the torque converter and ECU? This thread was the first thing that popped up in my search, but I also noticed a few posts about the newer models as well, and this one automotive professional newletter caught my eye describing the issue on 2019 and 2020 models and that a PCM update is the fix. Makes me think it could easily be smoothed out with tuning, but I don't know anyone tuning for just this (usually performance tunes for turbo cars).



Mazda modified its transmission to fight vibration from cylinder deactivation since 2018 MY. You should bring your CX-5 to a Mazda dealer with the TSB mentioned above and ask for the fix on this surging at low speeds issue under warranty.
 
Mazda modified its transmission to fight vibration from cylinder deactivation since 2018 MY. You should bring your CX-5 to a Mazda dealer with the TSB mentioned above and ask for the fix on this surging at low speeds issue under warranty.

TSB 05-002/20 states the PCM needs to be updated, and it covers the following Mazda models:

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.


TSB No.: 05-002/20 SURGING AT LOW SPEEDS AND DURING ACCELERATION
 
This vibration may be similar to what Honda owners have dealt with for years re: VCM. When cylinder deactivation is added to an engine, a common engineering approach appears to be suppressing vibrations by decreasing the durometer of engine, transmission and rear drive axle shaft and assembly mounts. The down side is that under certain conditions (usually low speed, moderate load and certain ambient temps), the softer mounts let the drivetrain oscillate where it can be felt. I'd bet the PCM update changes engine torque management and 1st lockup behavior.

I haven't looked, but do 2018 and newer use one or more active engine mounts (which could be PCM tweaked)?
 
Yeah, no doubt the torque converter is source (where the engine torque meets drivetrain resistance) and the resonance being "felt" is exacerbated by drivetrain mounts at particular conditions.
 
This vibration may be similar to what Honda owners have dealt with for years re: VCM. When cylinder deactivation is added to an engine, a common engineering approach appears to be suppressing vibrations by decreasing the durometer of engine, transmission and rear drive axle shaft and assembly mounts. The down side is that under certain conditions (usually low speed, moderate load and certain ambient temps), the softer mounts let the drivetrain oscillate where it can be felt. I'd bet the PCM update changes engine torque management and 1st lockup behavior.
The TSB says the surging at low speeds and during acceleration is in the longitudinal direction, and occurs in the locked up 1st gear. It’s caused by the torque fluctuation and the torsional resonance in the torque converter. The PCM is modified to reduce the torque fluctuation.

I haven't looked, but do 2018 and newer use one or more active engine mounts (which could be PCM tweaked)?
Based on this engine mount TSB, the revised #1 engine mount, KN3L-39-040 which replaces K157-39-040A, is applicable to all gen-2 CX-5’s, including 2017 CX-5 2.5L without cylinder deactivation. Thus having active engine mounts controlled by PCM should not be the case on CX-5.

TSB 01-022/18 - BODY VIBRATION WHEN ENGINE STARTED AFTER PARKING IN EXTREMELY COLD TEMPERATURES

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3F9FFD63-C352-44CD-9805-281C536A602D.jpeg
 
This vibration may be similar to what Honda owners have dealt with for years re: VCM. When cylinder deactivation is added to an engine, a common engineering approach appears to be suppressing vibrations by decreasing the durometer of engine, transmission and rear drive axle shaft and assembly mounts. The down side is that under certain conditions (usually low speed, moderate load and certain ambient temps), the softer mounts let the drivetrain oscillate where it can be felt. I'd bet the PCM update changes engine torque management and 1st lockup behavior.

I haven't looked, but do 2018 and newer use one or more active engine mounts (which could be PCM tweaked)?

The CD models definitely have the vibration issues because of CD. It’s just not dramatic enough for most people to notice it. It’s most noticeable below 2k. I have a few posts about where I’m questioning if the stupid CD can be disabled.
 
I have this issue with my '19 GT. Got the ECU software updated (TSB repair NOT covered under drivetrain warranty) and it fixed the problem for a couple hundred miles. Now it has returned, unfortunately. Very annoying.
 
I have this issue with my '19 GT. Got the ECU software updated (TSB repair NOT covered under drivetrain warranty) and it fixed the problem for a couple hundred miles. Now it has returned, unfortunately. Very annoying.
Mazda is the only hope to resolve this issue. Call Customer Experience Center, Mazda North American Operations and complain.
 
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Low speed wonkiness can be caused by a dodgy PCV valve (cycling open/closed, most noticeable at just off idle throttle). On these SkyActiv, not very easy to gain access to change, but maybe worth looking into.
 
Yeah, no doubt the torque converter is source (where the engine torque meets drivetrain resistance) and thet resonance being "felt" is exacerbated by drivetrain mounts at particular conditions.
I believe you are right in focusing on the issue of torque. However, in my experience the mounts would not account for a noticeable lug-then-jerk in 1st. or 2nd. gear, for example decelerating into a right and reaccelerating out of it. Despite the fact the TSB referenced in post #202 is intended to address a very specific circumstance, an unmistakable double-jerk, something I only experienced once over 4,000 miles, attributed to torque resonance, that TSB has sharply reduced low gear lugging in my experience--less frequent and when it occurs the lug is milder and briefer.
 
I just finished running errands in the local village in low speed driving (30 mph limit) with several traffic lights, stop signs, turns.

My final conclusion (unless the TSB affect "wears off", which I view with some skepticism, is there is a meaningful difference post-TSB in smoothing out low gear shifting and reducing low gear lug even though the TSB addresses only one very specific behavior.

It's where it ought to be now, not perfect (what is?), but given the limitations of a 187 hp, 4 cylinder, 6 speed set-up it meets my expectations.

Eventually I'll habituate myself to not obsessing about the vehicle's past behaviors, stop monitoring for every little trans blip and bump, and just drive. Probably won't take long.

I'm talking here about a 2020 AWD, and for that I highly recommend this TSB if the VIN qualifies. Other years or FWD? I imagine experiences could vary.
 
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