Reset ECU/TCU steps for your throttle response

[Guest vincemerz]

Guys,

can i confirm this pt:

1. At about in high way about 80km/hr in C mode, depress accelerator, from like 1800 RPM go to 3000 RPM, then let go accelerator, kinda quick to dropback to 2100 rpm followed by 1800 rpm again, quite fast in 2 stages.

2. At about in high way about 80km/hr in S mode, depress accelerator, from like 1800 RPM go to 3000 RPM, then let go accelerator, It will stay quite long at 3000 rpm and slowly drop gradually down towards 2000 rpm.

So can i say say S mode tends to stay in high revs?

actually not too sure how to benefit via using C or S mode...

any thoughts?

What about moving off from stationary S vs C mode?

[Guest vratenza]

Hi! i am assuming Merc use the same normenclature C/S across all it's applications regardless of transmission type (5AT vs 7G-tronic)

C is comfort mode= car always start off from 2nd gear unless u depress ur accelerator >3/4 from start. Gear change is aim at smoothness and fuel economy and thus will change up sooner. Recommended for slippery or snowy condition to prevent wheel spin. Also if u want a leisurely drive.

S is standard/sports mode= start from 1st gear and hold gear longer to achieve faster acceleration. Recommended for normal city driving.

[Guest mile]

vincemerz wrote:

Guys,

can i confirm this pt:

1. At about in high way about 80km/hr in C mode, depress accelerator, from like 1800 RPM go to 3000 RPM, then let go accelerator, kinda quick to dropback to 2100 rpm followed by 1800 rpm again, quite fast in 2 stages.

2. At about in high way about 80km/hr in S mode, depress accelerator, from like 1800 RPM go to 3000 RPM, then let go accelerator, It will stay quite long at 3000 rpm and slowly drop gradually down towards 2000 rpm.

So can i say say S mode tends to stay in high revs?

actually not too sure how to benefit via using C or S mode...

any thoughts?

What about moving off from stationary S vs C mode?

S (sport) mode changes the ECU mapping for more aggressive driving style, like when you want to drive fast and attack corners at high speed. You'll need to stay at lower gears through the bend, so it will upshift slower and down shift faster.

C (comfort) mode is more for leisurely drive. up shift very fast, and downshift slower.

My personal preference is C mode as it is more relaxing. But when i need to drive fast, i use the touchtronic manual shift to downshift or upshift whenever i want it.

I feel that S mode is a bit too aggressive on the highway, and too jerky for city driving. Probably good on track.

But for traffic light fast getaway,... use the S mode.

[Guest vratenza]

mile wrote:

S (sport) mode changes the ECU mapping for more aggressive driving style, like when you want to drive fast and attack corners at high speed. You'll need to stay at lower gears through the bend, so it will upshift slower and down shift faster.

C (comfort) mode is more for leisurely drive. up shift very fast, and downshift slower.

My personal preference is C mode as it is more relaxing. But when i need to drive fast, i use the touchtronic manual shift to downshift or upshift whenever i want it.

I feel that S mode is a bit too aggressive on the highway, and too jerky for city driving. Probably good on track.

But for traffic light fast getaway,... use the S mode.

For W203, the S mode is actually standard mode (maybe W204 onwards they change it to sports mode..I'm not sure). Read in the owner's manual that it is supposed to be the default mode for driving for most situation.

*funny thing is, the sales person who sold me the car was telling me that the C mode should be the default and S mode is for sports and only use it if you want to drive aggressively...so apparently alot of people gets confused over this as well*

Regarding your point about jerky for city driving, you may want to check your shifting quality from 1st gear to 2nd gear....is it when you feel a prominent jerk? And beyond the 2nd gear the rest of the upshifts are much smoother right?

If that is the case, it is NOT NORMAL...please go to C&C and ask them to check on that.

I experienced it whenever I am in S mode and it disappeared when I am in C mode. Putting together the fact that C mode shifts from 2nd gear onwards and the jerk seem to be only from traffic light start off in the lower gears, I came to a conclusion that there is a problem with the 1-2 gear shift.

Even my wife who is in the passenger seat can feel it commented that the jerk a little bit abnormal for a premium conti car.

To cut long story short, it turned out that an update on the TCU solves the problem...and the car now shifts like a dream in C or S mode:rockon:

oh, mine is the 7G-tronic gearbox...not sure if other gear box is affected but apparently a common problem in the international MB forums.

[Guest mile]

vratenza wrote:

For W203, the S mode is actually standard mode (maybe W204 onwards they change it to sports mode..I'm not sure). Read in the owner's manual that it is supposed to be the default mode for driving for most situation.

*funny thing is, the sales person who sold me the car was telling me that the C mode should be the default and S mode is for sports and only use it if you want to drive aggressively...so apparently alot of people gets confused over this as well*

Regarding your point about jerky for city driving, you may want to check your shifting quality from 1st gear to 2nd gear....is it when you feel a prominent jerk? And beyond the 2nd gear the rest of the upshifts are much smoother right?

If that is the case, it is NOT NORMAL...please go to C&C and ask them to check on that.

I experienced it whenever I am in S mode and it disappeared when I am in C mode. Putting together the fact that C mode shifts from 2nd gear onwards and the jerk seem to be only from traffic light start off in the lower gears, I came to a conclusion that there is a problem with the 1-2 gear shift.

Even my wife who is in the passenger seat can feel it commented that the jerk a little bit abnormal for a premium conti car.

To cut long story short, it turned out that an update on the TCU solves the problem...and the car now shifts like a dream in C or S mode:rockon:

oh, mine is the 7G-tronic gearbox...not sure if other gear box is affected but apparently a common problem in the international MB forums.

No. for W204 BlueEfficiency models, the user manual clearly states that C is default mode. Even if i switch to S, when i turn off the engine. And turn back on, it goes back to C.

1st to 2nd gear ... no jerk. In fact my wife, driving A170 with CVT (should be smoothest of all) asked if my C180K is also CVT cause she cant feel the shift at all.

When i mentioned jerk is the downshifting from 3-2-1.... which if you kickdown in S mode.... is a little jerky, and stays in the lower gear for too long. i sometimes manual up shift the gear when in S because i dont want to see my consumption keep increasing. ...

[Guest vratenza]

mile wrote:

No. for W204 BlueEfficiency models, the user manual clearly states that C is default mode. Even if i switch to S, when i turn off the engine. And turn back on, it goes back to C.

1st to 2nd gear ... no jerk. In fact my wife, driving A170 with CVT (should be smoothest of all) asked if my C180K is also CVT cause she cant feel the shift at all.

When i mentioned jerk is the downshifting from 3-2-1.... which if you kickdown in S mode.... is a little jerky, and stays in the lower gear for too long. i sometimes manual up shift the gear when in S because i dont want to see my consumption keep increasing. ...

Oh, so I think MB changed the nomenclature for the C/S again:rolleyes:

It does make sense that for Blue Efficiency models, MB will force the car to be in default C mode as it is the most fuel efficient (in line with the principle behind the model line) if you drive it smoothly with gradual acceleration and deceleration.

Out of curiosity, if your car is in C mode, does it roll back on a slope? Mine does because the 2nd gear is the default gear it start off from.

[Guest windss]

I don't roll back on slopes even if on C mode.. think it is the hill assist function?

[Guest vratenza]

windss wrote:

I don't roll back on slopes even if on C mode.. think it is the hill assist function?

oh, that's a nice feature to have.

I'm thinking maybe your C mode starts off from 1st gear as well.

so in W204, the C mode became the standard default driving mode while S mode became the Sports mode - more aggressive mode.

In w203, the S mode is the standard mode for default driving while C mode is for you to really relax and chill.

As you can see, there is a shift in Mercedes Benz's product focus towards the younger crowd who looks for a sportier drive traditionally dominated by BMW.:becky:

[Guest Cerano]

C is comfort

S is sport

ECU map doesnt actually change with the mode however, the ECU uses fuzzy logic and adapts to your driving style so if you drive more aggressively it will be more sporty.

Those having problem with 1-2 gear shift i suggest you do a manual TCU reset.

TCU resets are also good if you've driven in city traffic a long time because the TCU and ECU learn your driving style and will shift like a granny after start-stop traffic.

Resetting the TCU makes it new again.

To do a TCU reset, turn key to position 1, hold accelerator pedal for 10seconds, turn key before releasing pedal and give 5mins to reset

C mode can start from 1st gear if you push off the line aggressively, otherwise its 2nd gear.

[Guest mile]

Maybe for W203, S is for Sedate and C is for Control.

Jokes aside.

W204 does come with hill assist. So doesnt roll back at slope from stand still. But i know what you mean... sometimes at slow speed on slope when hill assist is disengaged, i do feel the car unable to climb,... i have to switch to S mode or shift the gear to D1 to get it moving.

[Guest vincemerz]

Cerano wrote:

C is comfort

S is sport

ECU map doesnt actually change with the mode however, the ECU uses fuzzy logic and adapts to your driving style so if you drive more aggressively it will be more sporty.

Those having problem with 1-2 gear shift i suggest you do a manual TCU reset.

TCU resets are also good if you've driven in city traffic a long time because the TCU and ECU learn your driving style and will shift like a granny after start-stop traffic.

Resetting the TCU makes it new again.

To do a TCU reset, turn key to position 1, hold accelerator pedal for 10seconds, turn key before releasing pedal and give 5mins to reset

C mode can start from 1st gear if you push off the line aggressively, otherwise its 2nd gear.

bro not too sure how to perform the TCU reset u mentioned... more advise...

[Guest vincemerz]

Position 1 is ? The first turn before the engine start turn?

So is after 10 seconds, turn the key back to off first then release pedal? Any indicators that will show on screen that it is being reset ?

[Guest vratenza]

Key positions:

Position 0: when the key is just inserted into the slot without any turning.

Position 1: turn the key one click to the right (clockwise).

Position 2: turn the key another click to the right (clockwise). This should be the last position before you crank the engine. To confirm that u are in this position, all your dash board warning signs will be displayed like a christmas tree decoration:becky:

Position 3: Crank position if u turn the key one more click to the right (clockwise) but note that this position will automatically return to Position 2 once you release the pressure on the key.

Reset ECU/TCU steps:

1) Make sure your car is stationary with the engine switched off and key out of the ignition and in your hand

2) sit in the driver seat

3) insert the key into position 0

4) turn the key 2 clicks clockwise to position 2

5) step on the accelerator pedal fully to the floor (until you activate the kickdown button at the end of the pedal travel) and hold for > 5 seconds. Don't need to be exact but I usually wait for about 10 seconds just to be safe..

6) now with your right foot still fully depressing the accelerator pedal, turn your key counter-clockwise to position 0 and hold for >1 second. I usually hold for 3-5 seconds without any detriment to the effort.

7) now release your right foot from the accelerator. Your key should still be in the ignition hole at position 0.

8) Wait for about 4-6 minutes (the timing have been reported to varies across different models)

9) in the mean time do not touch anything electrical/buttons in the car as the ECU/TCU sort of "reboot".

10) when time is nearly up, listen for a single "tack"-sound coming somewhere from the steering column. That is indication that your reset is successful

11) now take out your key from the ignition hole and you are done.

12) if you want to drive off immediately, still must complete step (11) before re-inserting the key to start your car as usual.After reset, you will notice that your car holds the gear longer as you drive around. Some say drive around your usual style so that it will learn it and adjust to your style optimally. Some say drive it aggressively for 10Km so that it will learn the more aggressive driving shifting and your car will be more responsive. What ever it is....you can try both ways...it's free anyway:bounce:

[Guest Cerano]

vratenza wrote:

Key positions:

Position 0: when the key is just inserted into the slot without any turning.

Position 1: turn the key one click to the right (clockwise).

Position 2: turn the key another click to the right (clockwise). This should be the last position before you crank the engine. To confirm that u are in this position, all your dash board warning signs will be displayed like a christmas tree decoration:becky:

Position 3: Crank position if u turn the key one more click to the right (clockwise) but note that this position will automatically return to Position 2 once you release the presure on the key.

Rest ECU/TCU steps:

1) Make sure your car is stationary with the engine switched off and key out of the ignition and in your hand

2) sit in the driver seat

3) insert the key into position 0

4) turn the key 2 clicks clockwise to position 2

5) step on the accelerator pedal fully to the floor (until you activate the kickdown button at the end of the pedal travel) and hold for > 5 seconds. Don't need to be exact but I usually wait for about 10 seconds just to be safe..:becky:

6) now with your right foot still fully depressing the accelerator pedal, turn your key counter-clockwise to position 0 and hold for >1 second. I usually hold for 3-5 seconds with detriment to the effort.

7) now release your right foot from the accelerator. Your key should still be in the ignition hole at position 0.

8) Wait for about 4-6 minutes (the timing have been reported to varies across different models)

9) in the mean time do not touch anything electrical/buttons in the car as the ECU/TCU sort of "reboot".

10) when time is nearly up, listen for a single "tack"-sound coming somewhere from the steering column. That is indication that your reset is successful

11) now take out your key from the ignition hole and you are done.

12) if you want to drive off immediately, still must complete step (11) before re-inserting the key to start your car as usual.

After reset, you will notice that your car holds the gear longer as you drive around. Some say drive around your usual style so that it will learn it and adjust to your style optimally. Some say drive it aggressively for 10Km so that it will learn the more aggressive driving shifting and your car will be more responsive. What ever it is....you can try both ways...it's free anyway:bounce:

hmm i thought its position 1 bro?

position 2 ah

[Guest vratenza]

Cerano wrote:

hmm i thought its position 1 bro?

position 2 ah

It's the position before the cranking of engine. Do let me know if it works differently for w204.:bounce:

[Guest io5885]

I tried resetting the ECU according to the steps u listed.

Thks bro. it worked well. :bounce:

Car feels livelier, throttle response more sensitive...

next to monitor is the fuel consumption.

As im the 2nd owner of my ride, the reset is very useful to me. :rockon:

[Guest Cerano]

vratenza wrote:

It's the position before the cranking of engine. Do let me know if it works differently for w204.:bounce:

thanks for the heads up (:

pretty sure you're right

cheers

[Guest vincemerz]

Mine can't work leh. No tick sound coming up to confirm reset done.

[Guest vincemerz]

I think manage to reset Liao, but I don't hear the tack sound.

Car now is smooth and back to the feeling of first day collecting car!!!

Power!!

Mine is c180 cgi

[Guest vratenza]

from my reading in the other merc forums, seem like this rest trick works for all merc models....even the AMGs are all swearing by it:whistle:...some of them even reset it every week!

Apparently the throttle/gear shift adaptation technology of merc is only good if you are a really consistent driver....ie. consistently slow accelerating and only feathering the throttle....OR....consistently driving like a mad man...

But in real life, how many drivers are that consistent? Even if they are, the city/highway/jam traffic difference will throw the adaptation off.... therefore giving you inconsistent and erratic shifting quality and points making it unpleasant to drive.

Regarding the tack sound, I only come across a few other drivers who post about hearing the same sound around 3-5 minutes after returning the key to position 0. So it's either too soft for some to hear, outside environment too noisy or some models may not have the same feedback sound.

[Guest xtrem]

vratenza wrote:

from my reading in the other merc forums, seem like this rest trick works for all merc models....even the AMGs are all swearing by it:whistle:...some of them even reset it every week!

Apparently the throttle/gear shift adaptation technology of merc is only good if you are a really consistent driver....ie. consistently slow accelerating and only feathering the throttle....OR....consistently driving like a mad man...

But in real life, how many drivers are that consistent? Even if they are, the city/highway/jam traffic difference will throw the adaptation off.... therefore giving you inconsistent and erratic shifting quality and points making it unpleasant to drive.

Regarding the tack sound, I only come across a few other drivers who post about hearing the same sound around 3-5 minutes after returning the key to position 0. So it's either too soft for some to hear, outside environment too noisy or some models may not have the same feedback sound.

Me try for two times also never hear that tack sound mention. Can i take it is reset liao? even though i never come across the sound? Can enlighten me, thanks u very much!

[Guest vratenza]

xtrem wrote:

Me try for two times also never hear that tack sound mention. Can i take it is reset liao? even though i never come across the sound? Can enlighten me, thanks u very much!

erm...i can't say for sure...since it is not a commonly reported feedback sound heard upon completion.

the best indication will be whether you feel any difference in your car's transmission shift and throttle response before and after:whistle:

[philipsim]

Old thread but kudos.

[hatch]

In normal mode, believe car drives off on 2nd gear.

Sports mode would start off on 1st holding gears longer before upshift

I do notice that its not smooth at low gear in normal mode.

Gonna try tis reset

[Skywalker]

just tried this reset and i can confirm that it works. The "tack" sound is very subtle. I did it at 1.30am in the carpark and i could barely hear it, though it was my leg adjusting against the side panel or something. Anyway, my c180 coupe felt like an altogether different beast after the reset. The gearbox doesn't shift into the upper gears as quick, so you get more torque out of it. Now I don't have to press the accelerator pedal as much to get the same burst from the car. It was really fun zipping around with the reset, almost reminding me of my previous mx5, but in much more comfort!

Anyway i'm gonna let me wife try it tomorrow and see if she can tell the difference. She's been lamenting that the mb is not as agile as the mx5 so i will see if this changes her mind