Subaru Solterra 2023-2026 Owner's Manual: Motor compartment

Components

1. Heater coolant reservoir
2. Washer fluid tank
3. Power control unit coolant reservoir
4. 12-volt battery
5. Brake fluid reservoir
6. Fuse box
7. Radiator
8. Condenser
9. Electric cooling fan

Checking the heater coolant

In the Subaru Solterra, the heater coolant level should always be checked when the EV system is completely cold. The level is considered correct if it is positioned between the "MAX" and "MIN" markings on the reservoir.

1. Reservoir cap
2. "MAX" line
3. "MIN" line

If the coolant level reaches or drops below the "MIN" line, carefully add coolant until it reaches the "MAX" line to maintain proper system operation in the Subaru Solterra.

■ Coolant selection

For optimal performance and long-term reliability of the Subaru Solterra, only use high-quality coolant such as "Toyota Super Long Life Coolant" or an equivalent ethylene glycol-based solution that is non-silicate, non-amine, non-nitrite, and non-borate, featuring long-life hybrid organic acid technology.

This coolant is typically pre-mixed at a 50/50 ratio with deionized water and обеспечивает защиту до температур примерно -31ºF (-35ºC). For precise recommendations, always consult your SUBARU dealer.

■ If the coolant level drops within a short time of replenishing

If you notice that the coolant level in your Subaru Solterra decreases rapidly after topping up, visually inspect components such as the radiator, hoses, reservoir caps, drain cock, and water pump for any signs of leakage.

If no visible issue is found, it is recommended to have your Subaru Solterra inspected by a qualified SUBARU dealer for pressure testing and system diagnostics.

WARNING

■ When the heater system is hot

Never remove the coolant reservoir cap when the system is hot.

The cooling system in the Subaru Solterra may be pressurized, and removing the cap could result in hot coolant spraying out, causing severe burns or injury.

NOTICE

■ When adding coolant

Coolant used in the Subaru Solterra must always be a properly balanced mixture of antifreeze and water. Using plain water or undiluted antifreeze can negatively affect lubrication, corrosion protection, and overall cooling efficiency. Always follow the specifications indicated on the coolant label.

■ If you spill coolant

Any spilled coolant should be rinsed off immediately with clean water to prevent damage to vehicle components or painted surfaces of the Subaru Solterra.

Checking the radiator and condenser

Regularly inspect the radiator and condenser of the Subaru Solterra and remove any debris such as leaves, dust, or insects that may obstruct airflow and reduce cooling efficiency.

If these components appear heavily загрязненими або ви сумніваєтесь у їх стані, зверніться до дилера SUBARU для професійної перевірки.

WARNING

■ When the EV system is hot

Avoid touching the radiator or condenser immediately after driving, as they may be extremely hot and can cause burns.

■ When the electric cooling fan are operating

Do not reach into the motor compartment of the Subaru Solterra while the cooling fan is operating.

Even if the vehicle appears inactive, the fan may automatically start when the power is ON, especially if the air conditioning is active or temperatures are elevated. Always ensure the power is OFF before working near these components.

Checking the power control unit coolant

The power control unit cooling system in the Subaru Solterra is critical for maintaining proper EV system performance. The coolant level should be checked when the system is cold and must remain between the "MAX" and "MIN" marks.

1. Reservoir cap
2. "MAX" line
3. "MIN" line

If the coolant level is низьким або знаходиться на позначці "MIN", долийте охолоджуючу рідину до рівня "MAX" для стабільної роботи системи Subaru Solterra.

■ Coolant selection

To ensure proper cooling of the traction battery and electronic components in the Subaru Solterra, only use "Genuine Traction Battery Coolant" or an equivalent low electrical conductivity coolant that is ethylene glycol-based, non-amine, non-borate, and contains azole additives.

Use of non-approved coolant may increase the risk of short circuits or system damage, and SUBARU cannot guarantee safe operation in such cases.

Never use plain water in the cooling system, as this can cause serious damage to the Subaru Solterra EV components.

Additionally, do not reuse drained coolant, as it may have lost its protective properties.

For further details, always consult your authorized SUBARU dealer.

■ If the coolant level drops within a short time of replenishing

If coolant levels continue to drop quickly in the Subaru Solterra, inspect hoses, reservoir caps, and associated components carefully for leaks or damage, and seek professional inspection if necessary.

If no visible leak can be identified in the Subaru Solterra cooling system, it is strongly recommended to have an authorized SUBARU dealer perform a professional inspection, including pressure testing of the reservoir cap and a thorough check for hidden leaks within the system.

WARNING

■ When the EV system is hot

Never attempt to open the power control unit coolant reservoir cap while the Subaru Solterra system is hot.

The cooling system may remain under high pressure, and removing the cap can cause горячий coolant to spray outward, leading to severe burns or injury.

NOTICE

■ When adding coolant

For the Subaru Solterra, coolant must always be a properly balanced mixture of water and antifreeze. Using only water or pure antifreeze may compromise lubrication, corrosion resistance, and cooling efficiency. Always follow the manufacturer’s specifications indicated on the coolant packaging.

■ If you spill coolant

Any spilled coolant on Subaru Solterra components or painted surfaces should be immediately rinsed off with clean water to prevent corrosion or cosmetic damage.

Checking and adding the brake fluid

■ Checking fluid level

The brake fluid level in the Subaru Solterra must be maintained between the "MAX" and "MIN" marks on the reservoir tank to ensure proper braking performance and safety.

1. Reservoir cap
2. "MAX" line
3. "MIN" line

■ Adding fluid

Before adding brake fluid to the Subaru Solterra, confirm the correct specification and prepare appropriate tools.

• Fluid type

FMVSS No.116 DOT 3 or SAE J1703 brake fluid

FMVSS No.116 DOT 4 or SAE J1704 brake fluid

• Item

Clean funnel

■ Brake fluid can absorb moisture from the air

Brake fluid used in the Subaru Solterra is hygroscopic, meaning it absorbs moisture from the air. Excess moisture can significantly reduce braking efficiency and compromise safety, therefore always use freshly opened brake fluid.

WARNING

■ When filling the reservoir

Brake fluid is hazardous and may irritate skin and eyes, as well as damage painted surfaces of the Subaru Solterra.

If brake fluid comes into contact with your skin or eyes, rinse immediately with clean water and seek medical attention if irritation persists.

NOTICE

■ If the fluid level is low or high

In the Subaru Solterra, a slight decrease in brake fluid level is normal as brake pads wear or when the accumulator fluid level changes.

However, if frequent refilling is required, this may indicate a serious issue that should be inspected by a SUBARU dealer.

Checking the 12-volt battery

Regular inspection of the Subaru Solterra 12-volt battery is essential to maintain reliable electrical system performance.

■ 12-volt battery exterior

Ensure that battery terminals are clean and free from corrosion, and check that all connections are secure. Also inspect for cracks in the battery casing and confirm that the hold-down clamp is firmly закреплен.

1. Terminals
2. Hold-down clamp

■ Checking 12-volt battery fluid

Verify that the electrolyte level is between the "UPPER LEVEL" and "LOWER LEVEL" indicators to ensure proper battery operation in the Subaru Solterra.

1. "UPPER LEVEL" line
2. "LOWER LEVEL" line

If the level reaches or drops below the "LOWER LEVEL" mark, add distilled water to restore it to the proper range.

■ Adding distilled water

1. Carefully remove the vent plug from the Subaru Solterra battery.

2. Add distilled water as needed to reach the correct level.

If the "UPPER LEVEL" marking is not clearly visible, inspect the fluid level directly inside the battery cell.

3. Reinstall the vent plug securely to prevent leakage or contamination.

■ Before recharging

When charging the Subaru Solterra 12-volt battery, hydrogen gas may be generated, which is highly flammable and potentially explosive. Follow these precautions carefully:

• If charging while the battery remains installed, disconnect the ground cable first to reduce electrical risk.
• Ensure that the charger power switch is turned off before connecting or disconnecting cables.

■ After recharging/reconnecting the 12-volt battery

• After reconnecting the Subaru Solterra battery, the EV system may not start immediately. Perform the following initialization steps:

1. Shift the vehicle into P (Park).

2. Open and close any door.

3. Restart the EV system.

• Immediately after reconnecting the Subaru Solterra battery, the Smart Key system may not function correctly. In this case, use the mechanical key or remote control to lock/unlock the doors.
• The EV system should be started with the power switch in ACC mode. If it fails on the first attempt, it will typically operate normally on the second attempt.
• The Subaru Solterra retains the previous power mode setting; after reconnecting the battery, the system will restore its last known state automatically.

Before disconnecting the 12-volt battery in the Subaru Solterra, always ensure that the power switch is completely turned off. If the previous power mode before disconnection is unknown, exercise additional caution when reconnecting the battery to avoid unexpected system behavior or electrical issues.

If the EV system of the Subaru Solterra still does not start after trying all recommended procedures, it is advisable to contact an authorized SUBARU dealer for professional diagnosis and support.

WARNING

■ Chemicals in the 12-volt battery

The 12-volt battery in the Subaru Solterra contains hazardous substances such as corrosive sulfuric acid and may emit hydrogen gas, which is highly flammable and explosive. To minimize the risk of injury or serious accidents, carefully follow these safety precautions when working near the battery:

• Avoid creating sparks by contacting the battery terminals with metal tools.
• Never smoke or use an open flame near the 12-volt battery.
• Prevent contact of battery electrolyte with eyes, skin, and clothing.
• Do not inhale fumes or ingest electrolyte under any circumstances.
• Always wear protective safety glasses when servicing the Subaru Solterra battery.
• Keep children away from the battery area at all times.

■ Where to safely charge the 12-volt battery

Recharge the 12-volt battery of the Subaru Solterra only in well-ventilated, open spaces. Avoid charging in enclosed areas such as garages without proper airflow, as accumulated gases may pose an explosion risk.

■ Emergency measures regarding electrolyte

• If electrolyte contacts the eyes, immediately flush with clean water for at least 15 minutes and seek urgent medical attention. Continue rinsing if possible while traveling to a medical facility.
• If electrolyte comes into contact with skin, wash the area thoroughly with water.

  If irritation, pain, or burning occurs, seek medical assistance immediately.

• If electrolyte spills onto clothing, remove contaminated garments immediately to prevent skin exposure and follow the necessary cleaning procedure.
• If electrolyte is accidentally swallowed, drink large amounts of water or milk and seek emergency medical help without delay.

■ When there is insufficient 12- volt battery fluid

Do not operate the Subaru Solterra if the battery fluid level is insufficient, as this may lead to overheating or even battery explosion.

NOTICE

■ When recharging the 12-volt battery

Never recharge the 12-volt battery while the EV system of the Subaru Solterra is active.

Ensure that all electrical accessories are switched off before starting the charging process.

■ When adding distilled water

Do not overfill the battery when adding distilled water. Excess liquid may overflow during charging and lead to corrosion or damage to surrounding components in the Subaru Solterra.

Adding the washer fluid

If the windshield washer system of the Subaru Solterra does not operate or a warning message appears on the multi-information display, the washer fluid reservoir may be empty and require refilling.

Add appropriate washer fluid to restore normal function.

WARNING

■ When adding washer fluid

Do not add washer fluid while the Subaru Solterra EV system is hot or running, as washer fluid often contains alcohol and may ignite if it comes into contact with hot engine components.

NOTICE

■ Do not use any fluid other than washer fluid

Using alternatives such as soapy water or antifreeze instead of proper washer fluid in the Subaru Solterra may result in streaking on painted surfaces and potential damage to the washer pump system.

■ Diluting washer fluid

When necessary, dilute washer fluid with water according to environmental conditions.

Always refer to the freezing temperature specifications indicated on the washer fluid container to ensure proper performance in the Subaru Solterra.