Electronic Stability Control and Traction Control systems

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Introduction

Suzuki added Electronic Stability Control (ESC / ESP) system in Jimnys somewhere in the period 2013-2015 (depending on the market).

Since then, ESC / ESP system for Jimnys has been optional in some markets, while it is mandatory in others.

More about the history of revisions to the Jimny vehicle model can be found in the Generic world Wikipedia article on Jimnys.

The typical mystery and confusion about ESC in Jimnys is how and when it exactly works, with the primary question bring whether it has any usefulness in all-terrain driving situations.

The purpose of this article is to clarify those mysteries and confusions (to the best knowledge of this forum's users).

Official documents

Suzuki's official leaflet for Jimny's ESC and TC

• This is official Suzuki's leaflet which describes the operation of Jimny's ESC system in a brief summary.
• The leaflet says that there are actually two systems - electronic stability control (ESC) system and traction control system (TC).
• So, it's not as straightforward as it is generally believed.
• What is not explained here is that the ESC and TC in Jimny are two separate systems.
• More on that will be explained below.

Switches and indicator lights

File:Suzuki Jimny - fog light and ESC control buttons - A01.jpg

Appearance and position of the ESC control switch (in an LHD Jimny)

• Jimnys, which have ESC (and TC) installed, also have a dedicated switch in the cabin to control the operation of the ESC system.
• It is the right-most switch in the three-switch cluster (above the external mirrors adjustment switch), together with the fog lamp control switches.
• The ESC switch has a symbol of a skidding vehicle (with the "OFF" letters beneath) imprinted on it.
• The ESC switch provides the driver with the possibility to turn ESC to ON or OFF state at will.
• While the switch is pressed IN, ESC is turned OFF.

The appearance of the latest (3rd edition) Jimny instrument panel

• All Jimnys which have ESC (and TC) should also have the latest (3rd edition) instrument panel, like the one on this picture.
• This is a picture of such instrument panel from a Jimny sold in continental Europe, with all the indicator lamps turned on.

• Notice the two yellow indicator symbols and one orange symbol at the bottom of the center circle.

• The left yellow indicator symbol (a skidding vehicle) is inactive 99% of the time.
• It will just blink intermittently (sporadically) only when the ESC or the TC system "kicks in" during a predicament (when vehicle starts to skid on road or when it loses traction off road).
• This means that this indicator light is shared by the two systems.

• The center yellow indicator symbol (a skidding vehicle with "OFF" letters below it) will be constantly lit all the time while the ESC button is pressed in, and also during the entire time while the vehicle is in 4WD-L mode (no matter if the ESC button is pressed or not).
• Otherwise, it is inactive.

Operation of the ESC and TC systems

General principle

• The programming is such that Jimny's ESC system works only in 2WD-H and 4WD-H transmission modes, and the TC system works only in 4WD-L transmission mode.
  • Therefore, only one (or none) of those systems can be active at a certain point in time, but not both at once.

• Both systems share the same operation indicator light on the instrument panel.
  • It is the leftmost bottom yellow symbol in the center section, as shown in the picture above.

ESC domain

• The ESC system in a Jimny works as a typical vehicle stability control system.
  • This means that ESC monitors if the vehicle has started to skid or to spin out (on a bend for example).
    • If that happens, ESC attempts to correct vehicle's trajectory by swiftly manipulating each individual wheel brake, engine throttle, etc.
• ESC is not effective in situations when vehicle has lost momentum due to the loss of traction on one or more wheels, and needs to continue further from that point.
  • This is a typical off-road predicament.

TC domain

• When the vehicle shifts into 4WD-L mode, the ESC system automatically turns OFF and the TC system automatically turns ON.
  • This happens in 4WD-L mode regardless if the ESC button is pressed in or not.
  • In other words, while the vehicle is in 4WD-L mode, ESC will be OFF and TC will be ON, whether that is desired by the driver or not.

• In 4WD-L mode, the TC system will monitor if any wheel is staring to spin.
  • If that happens, TC will selectively and intermittently apply the brake on the spinning wheel.
• Its goal is to fool the axle differential to "hand over" the torque to the other wheel on that axle, which presumably has more traction than the useless wheel.
  • This is very similar in concept to the traction control systems found in many other 4WD vehicle models (Land Rover Discovery 2 for example).
• This in practice means that Jimny's TC system can significantly aid the driver off-road on some slippery slopes and especially in cross-axle off-road situations.

• When the vehicle returns from 4WD-L transmission mode back into 4WD-H or 2WD-H mode, TC will automatically turn OFF and ESC will automatically turn ON (if the ESC switch is not pressed in).

Disadvantages of the programming

• The inability to turn off the TC system in 4WD-L mode can be a disadvantage in certain all-terrain driving situations.
  • Example is when charging up a slippery hill (for example: a very loose gravel incline or a muddy incline).
    • In this case, when all four wheels are furiously spinning and spraying gravel or mud all around, TCS will start selectively and intermittently breaking all of them.
      • This will "steal" vehicle's momentum and lead it to a standstill on the middle of the ascent, or even to an engine stall.
        • It's almost like charging up a hill and then simultaneously applying both the brakes and the throttle in the middle of the critical struggle during the ascent - like shooting yourself in the foot.
• It is unclear why Suzuki decided not to provide a way for the driver to turn off TC in 4WD-L mode if the driver desired so.
  • The ESC button could have been utilized for that (to be a shared "ESC / TC" OFF button), just like the above mentioned indicator lamp on the instrument panel is a shared lamp.

Professional tests and reviews

Review from Australian Practical Motoring magazine

• Read this professional Australian off-road test drive review of a Jimny with ESC/TC.
• The review focuses specifically on the ESC/TC systems in the new Jimny, and evaluates the operation of the systems in all terrain conditions.

Test on rollers in Poland

Here is a Polish video which vividly portrays the operation of Jimny's ESC and TC systems in a controlled environment:

• The test on rollers simulates the loss of traction in off-road conditions.
• It clearly shows the ineffectiveness of the ESC system in 4WD-H mode, and the effectiveness of the TC system in 4WD-L mode.

Conclusions

To summarize, here are several key points.

• Jimnys, which have ESC, have in fact two separate systems - ESC and TC.

• ESC works only in 2WD-H and 4WD-H mode.
  • It is ON by default, but it can be turned OFF by the driver.
• ESC is useful on-road, but rather useless off-road.
  • In 2WD-H and 4WD-H modes, the ESC system is useful to prevent vehicle from skidding or spinning out during relatively high velocities on bends etc.
• ESC turns OFF automatically (if it has not already been turned off by the driver) when 4WD-L transmission mode is engaged.

• TC works only in 4WD-L transmission mode, and it can not be turned off while the vehicle is in that mode.
• TC works relatively effectively to aid vehicle's traction in slippery or cross-axle off-road situations.
• The state of the ECS button on the dashboard has nothing to do with the operation of the TC system.

• Both ESC and TC share the same operational indicator light on the instrument panel.

• Both ESC and TC are probably operated by the same dedicated controlling computer.
• The computer probably just has two different operational / programming modes (one for ESC and one for TC).
  • Therefore, ESC and TC are two logically separate systems (they are separate from the operational and driver's point of view).

Special note

• Don't forget that these are unofficial conclusions based on inputs from various forum members and from a few Internet sources.
• It could easily be possible that the programming of Jimny's ESC/TC controller differs for different world markets!

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Page last edited on 27/01/2018 by user Bosanek