GWM Tank 300 Safety Systems: ESC, ABS, HHC and Rollover Prevention Explained
The GWM Tank 300 runs ABS, electronic braking force distribution, brake assist, traction control, electronic stability control, rollover prevention, secondary collision mitigation and hill-start hold control. ESC is on throughout normal driving and should only be switched off for tyre chains, deep snow or soft ground, or to free a stuck vehicle. It turns itself back on every time you start the engine and whenever speed exceeds 85 km/h. HHC holds braking force for about 2 seconds on a slope, and on gradients steeper than 30 percent the vehicle can still roll.
What each system actually does
Anti-lock brake system (ABS) prevents the wheels locking under braking on wet and slippery roads, so you keep steering control.
Electronic braking force distribution (EBD) adjusts the front to rear braking ratio automatically, improving braking efficiency and stability alongside ABS.
Brake assist detects a very fast pedal application and increases braking effect to shorten the stopping distance in an emergency.
Traction control (TCS) keeps driving force available and stops the driven wheels spinning when you start or accelerate on a wet, slippery surface.
Electronic stability control (ESC) reduces the risk of a side slip by braking individual wheels when the vehicle starts to deviate from your intended path.
Rollover prevention (RMI) monitors vehicle movement through corners and, if it detects a rollover risk, decelerates one or more wheels to prevent it.
Secondary collision mitigation (SCM) applies the brakes automatically after a first impact where the airbags deploy, slowing or stopping the vehicle to reduce the chance of a second collision.
Hill-start hold control (HHC) maintains braking force for about 2 seconds when you release the brake on a slope, so the vehicle does not roll back before the throttle takes over.
The ABS fact nobody wants to hear
ABS is not designed to shorten braking distance. It exists to keep the wheels turning so you can steer.
In several conditions the Tank 300 with ABS may actually need a longer distance to stop than a vehicle without it:
- Muddy, gravel or snowy roads
- Driving with tyre chains fitted
- Bumpy roads
- Potholes and uneven surfaces
It may also fail to work effectively when tyre grip limits are exceeded, such as excessively worn tyres on snow, or at high speed on a wet, slippery road.
There is also a technique point that matters. During emergency braking, do not pump the pedal or press it gently. Either lengthens the braking distance. Press firmly and hold.
The vibration you feel and the motor noise you hear while ABS works are normal, not a malfunction.
Comparison table: when each system is active
| Attribute | ABS | ESC | TCS | HHC |
|---|---|---|---|---|
| Purpose | Maintain steering under braking | Prevent side slip | Prevent wheelspin on take-off | Prevent roll-back on a slope |
| Measurement (key figure) | No distance benefit, sometimes longer | Auto on above 85 km/h | Active on wet or slippery starts | Holds for about 2 seconds |
| Driver switchable | No | Yes, in limited conditions | Via expert mode | No |
| Off by default in 4H and 4L | No | Yes | Depends on setting | No |
| Warning light behaviour | Solid means fault | Flashing means working, solid means fault | Shown via ESC indicators | Shown via indicator |
| Known limitation | Loose and uneven surfaces | Cannot beat physics | Cannot create grip | Fails above 30 percent gradient |
When you are allowed to turn ESC off
ESC is on throughout the driving process by default, and the manual permits switching it off in only three situations:
- Driving with tyre chains
- Driving in deep snow or on soft ground
- Freeing a stuck vehicle
Reactivate it as soon as you leave those conditions. It will also reactivate itself every time you start the engine, and automatically above 85 km/h.
Press the ESC OFF button after starting to disable it, at which point the yellow ESC OFF indicator illuminates. Press again to restore it.
One behaviour catches people out constantly: when ESC is actively working, the yellow ESC warning light flashes. That is the system doing its job, not reporting a fault.
ESC and the terrain modes
Selecting 4H or 4L switches ESC off by default, which is deliberate. Stability intervention works against you when you need controlled wheelspin to clear an obstacle.
The consequence is worth stating plainly: in low range, on a side slope, with a locker engaged, there is no electronic safety net catching a slide.
Expert mode gives finer control, letting you store ESC as ALL-ON, TCS and VDC off, or ALL-OFF alongside your drive and steering mode choices.
HHC has a hard limit
Hill-start hold control holds the brakes for roughly 2 seconds after you lift off the pedal on a slope, which is enough for a normal hill start.
On a gradient steeper than 30 percent, the vehicle may still roll, and the manual is explicit that you should not rely excessively on this function. Treat HHC as a convenience rather than a safety device on steep tracks.
The modification warning that matters most
Suspension modification, or the use of tyres or wheels of a non-specified size, will impact the driving assist systems and may cause system malfunctions.
That is not a warranty scare line. These systems calculate wheel speeds, yaw rates and vehicle attitude against expected values. Change the rolling diameter, the track width or the ride height enough, and the numbers the systems work from no longer describe the vehicle they are fitted to.
The practical approach is to keep changes within the sizes and ranges specified for the vehicle, and to treat any accessory that alters geometry or rolling diameter as something that affects the electronics as well as the look.
A dashboard behaviour that is not a fault
When a vehicle is started after battery loss, the engine may not run smoothly and the ABS or ESC warning light may come on. This is caused by low battery voltage and does not mean those systems are faulty.
Common mistakes Tank 300 owners make
- Assuming ABS shortens stopping distances. On loose and uneven surfaces it can lengthen them.
- Pumping the brake pedal in an emergency. Press firmly and hold.
- Reading a flashing ESC light as a fault. Flashing is the system working.
- Leaving ESC off after a recovery. Turn it back on the moment you are clear.
- Trusting HHC on a very steep track. Above 30 percent gradient it may not hold.
- Fitting non-specified tyre or wheel sizes and expecting the electronics to adapt.
- Lifting the suspension without considering the assist systems.
- Treating ABS vibration or motor noise as a problem.
- Relying on stability control in 4H or 4L, where it is off by default.
- Blaming the ABS light after a jump start instead of the battery.