Shut off TCS for a day!

:
2017 Mazda 6 Sport

technology_active-safety_bk-ebd_en_1st-row_img.ts.1602150246006430.jpg
 

HardRightEdg

US 2020 CX-5 Touring AWD Soul Red
As far as I know all CX5 gen2 have the same specs except the Turbo which has larger front discs and most likely pads. I have somewhere the discs dimensions if you are interested let me know and I can take a look.
The idea that the CX-5 EDB is designed with rear bias, causing excessive rear brake wear, is not borne out by the smaller rear pads. I was curious to know if rotor specs reinforce that assessment. Larger front rotors on the turbo would further indicate the traditional front bias.
 
:
CX5 GT
inches/mm
rear Solid disc (11.9/303) diameter
front non turbo Ventilated disc (11.7/297) diameter;
front turbo Ventilated disc (12.6/320)

It does have lots of rear braking bias. I tested stopping 60 to 0 in the past and observed that the car does not plunge forward as much as in other cars I had in the past.
 
Last edited:

yrwei52

2016 Mazda CX-5 GT AWD w/Tech Pkg
Contributor
:
Plano, Texas, USA
Are those specs for a particular gen, year, trim? AWD vs FWD or turbo vs. non? I know, that's a lot of questions. Anyway, for the version(s) you're quoting I'd be curious to know the OEM rotor spec differences between front and rear.
The specs are for gen-1 CX-5 FWD and AWD but should be the same on gen-2 CX-5’s except the 2.5T with bigger front brakes.


The specs on rotors:

Front brake (disc)
Pad dimensions (area x thickness) (mm2 x mm {in2 x in}) 6,000 x 10 {9.300 x 0.39}
Disc plate dimensions (mm {in}) 297 x 28 {11.7 x 1.1}

Rear brake (disc)
Pad dimensions (area x thickness) (mm2 x mm {in2 x in}) 2,800 x 8.5 {4.340 x 0.33}
Disc plate dimensions (mm {in}) 303 x 10 {11.9 x 0.39}


Mazda CX-5 Service & Repair Manual: Brakes
 

HardRightEdg

US 2020 CX-5 Touring AWD Soul Red

technology_active-safety_bk-ebd_en_1st-row_img.ts.1602150246006430.jpg
That's pretty interesting. Except for full loads, the braking is front biased. This is consistent with the video I posted--light load, panic stop, nose diving. It is also consistent with smaller rear pads under a Mazda assumption most drivers don't drive will full loads most of the time. The larger rear rotors is a counterpoint. Drivers who do not fit the low-load profile might see more rear brake wear.

At 8,000 miles on the OD, 4,000 of which were mine and 4,000 dealer loaner miles, my front and rear pads showed equal wear per a dealer check. Now at 12,000 on the OD, I've only had a heavy load for about 150 miles over my 8,000 total and I expect that to be typical going forward. Hauling people and stuff is almost always the Sienna's job.

I'll see where I'm at with the next oil change around next June at about 18.000 miles. So far so good. I'd say the over/under bet is equal wear.
 
Last edited:

HardRightEdg

US 2020 CX-5 Touring AWD Soul Red
The specs are for gen-1 CX-5 FWD and AWD but should be the same on gen-2 CX-5’s except the 2.5T with bigger front brakes.


The specs on rotors:

Front brake (disc)
Pad dimensions (area x thickness) (mm2 x mm {in2 x in}) 6,000 x 10 {9.300 x 0.39}
Disc plate dimensions (mm {in}) 297 x 28 {11.7 x 1.1}

Rear brake (disc)
Pad dimensions (area x thickness) (mm2 x mm {in2 x in}) 2,800 x 8.5 {4.340 x 0.33}
Disc plate dimensions (mm {in}) 303 x 10 {11.9 x 0.39}


Mazda CX-5 Service & Repair Manual: Brakes
That's interesting. So, slightly larger discs on the rear to go with smaller pads on the non-turbo. Seems like an odd choice.
 
:
Ottawa, Ontario
:
17 Mazda 6 GT
Ok, so getting back to the -TCS and my cruise control not working- post I made earlier. I did some testing this afternoon.
Result (drum roll please) is that the radar cruise does indeed disengage when turning off (disabling) the traction control system (TCS). If I have it (TCS) disabled already, and then try to engage my cruise control, it won't let me.
Conversely, if I am driving using the radar cruise, and push the TCS button, the cruise will disengage and it gives me a message that says my radar cruise has been disabled.
The key factor here is ...radar cruise. If I run with the regular, non-radar, cruise option enabled, it will not disengage when I push the TCS button. That was my ah ha moment.
-In a nutshell, it is only the radar cruise option that doesn't work when the TCS is turned off.
Regular cruise works fine either way.
I guess if your model doesn't have radar cruise control, then there is no issue.
Hope that helps.
 
:
Ottawa, Ontario
:
17 Mazda 6 GT
My default on start up is the TCS off light is on..
Mine is the opposite.
The TCS light is off, meaning traction control is enabled.
If I want to turn off the traction control system, I have to do it every time I start the car.
It can be a little confusing. If the light is off, it means the TCS is enabled.
If the light is on, it means the TCS is off. Takes a little getting used to.
 
:
Ottawa, Ontario
:
17 Mazda 6 GT
It does have lots of rear braking bias. I tested stopping 60 to 0 in the past and observed that the car does not plunge forward as much as in other cars I had in the past.
I would have to concur with those observations.
My previous older vehicles had a much more pronounced nose dive effect, especially those that still had drums in the rear.
My 6 seems to brake pretty level. Much improved over earlier vehicles I had.
 
:
2020 CX5 AWD
Mine is the opposite.
The TCS light is off, meaning traction control is enabled.
If I want to turn off the traction control system, I have to do it every time I start the car.
It can be a little confusing. If the light is off, it means the TCS is enabled.
If the light is on, it means the TCS is off. Takes a little getting used to.
Im a idiot. Figured it out.
 
:
GA prior 16 CX5 GT
:
20 CX5 GT + Prem
I bet the brake pad size surface area is proportional to the brake wheel cylinder surface area so the same brake fluid pressure will give the same relative pad surface area braking pressure front vs rear. Anybody know the surface area of the wheel cylinders front and back and turbo? The greatest wear rate on the pads is in hard braking and ABS will limit rear braking or the back wheels would lock up.
 

HardRightEdg

US 2020 CX-5 Touring AWD Soul Red
Ok, so getting back to the -TCS and my cruise control not working- post I made earlier. I did some testing this afternoon.
Result (drum roll please) is that the radar cruise does indeed disengage when turning off (disabling) the traction control system (TCS). If I have it (TCS) disabled already, and then try to engage my cruise control, it won't let me.
Conversely, if I am driving using the radar cruise, and push the TCS button, the cruise will disengage and it gives me a message that says my radar cruise has been disabled.
The key factor here is ...radar cruise. If I run with the regular, non-radar, cruise option enabled, it will not disengage when I push the TCS button. That was my ah ha moment.
-In a nutshell, it is only the radar cruise option that doesn't work when the TCS is turned off.
Regular cruise works fine either way.
I guess if your model doesn't have radar cruise control, then there is no issue.
Hope that helps.
Your 2017 Mazda 6 manual (Mazda web site non-PDF version using the "Advanced" index search) answers a question and raises others.

It calls the switch "DSC OFF", not "TSC OFF" as in my CX-5, and the manual shows the switch having the swerving car icon instead of just "TCS OFF". The manual says, "Press the DSC OFF switch to turn off the TCS/DSC. The DSC OFF indicator light in the instrument cluster will illuminate." It looks like those functions are tightly integrated in your vehicle with the suggestion that both are either on or off. How integrated in my CX-5 with a "TCS OFF" function remains an open question in my mind.

Next, the section in the 2017 manual covering radar cruise says it will not operate unless the DSC is "operating normally". There's your answer if "off" constitutes abnormal operation. I think that's a good bet.

Also the Distance Recognition System will not operate if the DSC "has a malfunction". Would that including having it off? I'd guess so. The manual says that feature is in "some models". If you've got it I suppose it could be tested with care at the "far" setting to see if it squawks. The manual does not mention this system applying brakes, just warnings. If that's true, why DSC has to be functioning properly is a puzzler.

Not all versions of i-ACTIVESENSE are alike, if that's not stating the obvious. I also wouldn't count on brake assist / EBD (or anything else) working the same across all models or even different years within models. Undocumented tweaks are always a possibility going from year to year.
 
Last edited:
:
2020 CX5 AWD
Wow. improved pedal response. Shifts are precise and acceleration is improved to somewhere between sport and manual modes. The improvements under 2k rpm are the most noticeable.

Im not sure but the car idles and starts differently with TCS off under 2k rpm. Not like before when the cylinder deactivation would be enabled while stopped and then released once moving again. Or when before, youd be cruising and have to really depress the accelerator to get the trans to downshift and wait as it searched for a lower gear, whereas now just a slight tip of the accelerator gets a prompt down shift in comparison.

This makes me wonder what disabling TCS does, if anything to the cylinder deactivation? Do you think if i drove with TCS disabled, while viewing the MPG cylinder deactivation screen up i could determine if its still being deployed or not.
 

HardRightEdg

US 2020 CX-5 Touring AWD Soul Red
Wow. improved pedal response. Shifts are precise and acceleration is improved to somewhere between sport and manual modes. The improvements under 2k rpm are the most noticeable.

Im not sure but the car idles and starts differently with TCS off under 2k rpm. Not like before when the cylinder deactivation would be enabled while stopped and then released once moving again. Or when before, youd be cruising and have to really depress the accelerator to get the trans to downshift and wait as it searched for a lower gear, whereas now just a slight tip of the accelerator gets a prompt down shift in comparison.

This makes me wonder what disabling TCS does, if anything to the cylinder deactivation? Do you think if i drove with TCS disabled, while viewing the MPG cylinder deactivation screen up i could determine if its still being deployed or not.
The caption under your handle says 2014. Cylinder deactivation was introduced in 2018.
 
:
CX5 GT
Wow. improved pedal response. Shifts are precise and acceleration is improved to somewhere between sport and manual modes. The improvements under 2k rpm are the most noticeable.

Im not sure but the car idles and starts differently with TCS off under 2k rpm. Not like before when the cylinder deactivation would be enabled while stopped and then released once moving again. Or when before, youd be cruising and have to really depress the accelerator to get the trans to downshift and wait as it searched for a lower gear, whereas now just a slight tip of the accelerator gets a prompt down shift in comparison.

This makes me wonder what disabling TCS does, if anything to the cylinder deactivation? Do you think if i drove with TCS disabled, while viewing the MPG cylinder deactivation screen up i could determine if its still being deployed or not.

Thats what I am wondering too. Can you turn off the TCS and open the monitor app (assuming yours is 2020) while driving and see what it shows?
 
:
2018 CX-5 Sport
I tested mine with TCS off and noticed no mpg improvement and no acceleration difference. Mine is the sport trim which doesn't have all the whistles and bells that other trims have. No radar, no lane assist etc. It does have CD.
 

HardRightEdg

US 2020 CX-5 Touring AWD Soul Red
Thats what I am wondering too. Can you turn off the TCS and open the monitor app (assuming yours is 2020) while driving and see what it shows?
I did about 70 miles of back road driving and testing today, comparing TCS off vs. on. Some of that was without my wife telling me to stop fooling around. ;) My version of the vehicle in conveniently captioned at the upper left. :rolleyes:

One more preface: my PCM was updated in June 2021 which I suspect had a minor alteration to the torque curve which sharply reduced my lugging issues. Results may vary with earlier or later PCM versions of the captioned vehicle. Other years, trims, drive trains may vary.
  • The TCS OFF switch disables Lane Keeping / Lane Departure as the manual states. That's per the lane display in the right dash pod showing the vehicle always planted in the middle of the lane while driving over lines known to trigger it. No steering wheel vibrations or lane adjustments. The LK/LD disabled warning light does not appear on the dash, which seems odd.​
  • TCS OFF does not disable radar cruise as reported for the 2017 Mazda 6 with DSC OFF. This was verified by cruising up on a slower vehicle. This is consistent with the manual which makes no mention of such disabling.
  • TSC OFF does not disable cylinder deactivation. That's confirmed in seeing the real time gas mileage monitor jump to 60 mpgs or even bury at 80 mpgs with cruise off at a steady 50 mph with light gas and the cylinder monitor showing two cylinder operation.
  • I have not attempted to ascertain affects on Dynamic Stability Control, Smart Brake Support or Smart City Brake Support. Those tests would be potentially dangerous, or certainly so in testing differences in stability control performance. At least the manual doesn't mention any affect on these systems with TCS OFF but I wouldn't bet my life on it.
  • The manual states system overrides of driver inputs are altered with TCS OFF in manual shift mode. I did not test it. I don't use it. Those days are behind me. Be aware and check the manual for details if you use the manual shifter.
  • I find no difference in vehicle performance and shifting except for one note: TCS OFF has the vehicle do what it does with slightly less gas pedal pressure in getting up to speed. That's not be confused with a semi-sport mode since it revs about the same to it's shift points when adjusting pedal pressure for the difference. If out of habit I work the gas as normal in TCS OFF mode, the vehicle seems friskier getting up to speed, but that's really a performance illusion. If I add a little more gas then usual in normal mode, it behaves the same as TCS OFF.
  • In an unscientific monitoring of gas mileage on a 40 mile round trip with TCS OFF, a trip I make frequently with a good sense it come in around 28-29 mpg with TCS on, the difference is negligible or non-existent. Given less gas pedal pressure in getting up to speed with TCS OFF in daily driving mode I find this surprising, but it is what it is.
  • I need more hobbies.
 
Last edited: