2022 Volvo S90 Recharge Plug-in Hybrid Brakes
Brake fluid – specifications
Brake fluid is the medium in a hydraulic brake system that is used to transfer pressure from e.g. a brake pedal via a master brake cylinder, which in turn acts on the brake calipers.
Prescribed grade: Volvo Original or equivalent fluid compliant with a combination of Dot 4, 5.1, and ISO 4925 class 6.
NoteIt is recommended that brake fluid is changed or filled by an authorized Volvo workshop.
Brake functions
The car’s brakes are used to reduce the speed or prevent the car from rolling.
Besides the foot brake and parking brake, the car is equipped with several automatic brake assist functions. These can assist the driver by not needing to keep his/her foot on the brake pedal when at a traffic light, or when starting on an uphill gradient.
Depending on the car’s equipment, the following auto braking functions are available:
- Automatic brake when stationary (Auto hold)
- Hill start assist (Hill Start Assist)
- Auto braking after a collision
- Regenerative braking
- Warning and auto-brake when reversing
- Assistance at risk of collision
Automatic braking when stationary
Automatic brake when stationary (Auto hold) means that the driver can release the brake pedal while maintaining a braking effect when the car has stopped at traffic lights or a junction.
When the car has stopped, the brakes are activated automatically. The function can use either a foot brake or a parking brake to hold the car stationary and it works on all gradients. When driving off, the brakes are released automatically if the driver is wearing the seatbelt and/or the driver’s door is closed.
NoteWhen braking to a standstill on an uphill or downhill slope, the brake pedal should be depressed a little harder before being released to ensure the car does not roll.
The parking brake is activated automatically
- if the car is switched off
- when the driver unbuckles the seatbelt and/or opens the driver’s door.
- if the function Auto hold (brake when stationary) is activated and the car has been stationary for a while (approx. 5–10 minutes).
Auto hold can also change over to the parking brake in other situations.
Symbols in the driver display
| Symbol | Specification |
|---|---|
 |
The symbol is illuminated when the function uses the foot brake to keep the car stationary. Note that the foot brake may be active even if the symbol is not lit. |
 |
The symbol is illuminated when the function uses the parking brake to keep the car stationary. |
Activating and deactivating the automatic brake at a standstill
The automatic brake function at a standstill is activated using the button in the tunnel console.
- Press the button in the tunnel console to activate or deactivate the function.
The indicator in the button illuminates when the function is activated. The activated function remains even when the car is started next time.
Applicable when switching off
If the function is active and holds the car with the foot brake (A-symbol illuminated in the driver display), the brake pedal must be depressed at the same time as the button is depressed in order to deactivate.
- The function remains deactivated until it is reactivated.
- When the function is deactivated, brake assist remains active to prevent the car from rolling backward when starting on an uphill gradient.
Auto braking after a collision
In the event of a collision in which the activation level is reached for the pyrotechnic seatbelt tensioners or airbags, or if a collision with a large animal is detected, the car’s brakes are automatically applied. This function is to prevent or reduce the effects of any subsequent collision.
After a serious collision, there is a risk that it is no longer possible to control and steer the car. In order to avoid or mitigate a possible further collision with a vehicle or an object in the vehicle’s path, the auto braking system is activated automatically and brakes the car in a safe manner.
Brake lights and hazard warning lights are activated during braking. When the car has stopped, the hazard warning lights continue to flash and the parking brake is applied.
If braking is not appropriate, e.g. if there is a risk of being hit by the following traffic, the system can be overridden by the driver depressing the accelerator pedal.
The function assumes that the brake system is intact after the collision.
Brake assistance when stationary
(Option/accessory)
Brake assist can be automatically activated to hold the car stationary in certain situations.
Brake assist is available even when automatic braking when stationary (Auto Hold) is deactivated.
Brake assist is activated:
- When stationary if gear position D or R is selected and the car is at risk of starting to move in the opposite direction to the selected direction of travel
- When stationary if creep mode is deactivated
Brake assist is deactivated:
- When gearing position D or R is selected and the driver depresses the accelerator pedal
- When the driver selects gear position N
The parking brake is activated automatically
- if the car is switched off.
- when the driver unbuckles the seatbelt and/or opens the driver’s door.
- if the function Auto hold (brake when stationary) is activated and the car has been stationary for a while (approx. 5–10 minutes).
Regenerative braking
(Option/accessory)
The car recovers kinetic energy during braking in order to reduce fuel consumption and emissions.
The function is available in all drive modes together with gear position D or B.
Energy recovery with the brake pedal
- Depress the brake pedal.
- The car brakes and regenerates energy.
Energy recovery with the accelerator pedal
- Release the accelerator pedal.
- The car brakes and regenerates energy.
Regeneration increases during engine braking when manual gearshift mode B is selected.