Peugeot 308 III Indicators: Red Warnings (2025-present)

A red warning lamp on your Peugeot 308 tells you about a fault that needs attention or something you need to deal with. Some red lamps light up for a few seconds when you switch on the ignition and should go out once the engine has started. If a red lamp comes on and stays on, there may be a fault that needs investigating. A lamp can light up steadily or flash, and it may come with a beep or a message on the screen.

This guide covers the Peugeot 308 III (2025-present), based on handbook edition ed09-25 for vehicles produced from 12/09/2025. Some lamps only appear on certain versions or equipment levels, such as the MHEV, PHEV, BEV or BlueHDi diesel versions, so not every lamp here will apply to your car.

Quick Reference

Maximum coolant temperature

This is the red coolant temperature warning lamp. When it stays on, the temperature of the cooling system is too high.

What to do:

• Stop somewhere safe.
• Wait until the engine has cooled down, then top up the coolant if needed.
• If the problem continues, switch off the engine and get help from a workshop.

Engine oil pressure (ICE, MHEV or PHEV)

This is the red engine oil pressure warning lamp, used on ICE, MHEV and PHEV versions. When it stays on, there is a fault with the engine lubrication system.

What to do:

• Have the fault put right by a workshop straight away.

System malfunction (MHEV, PHEV or BEV)

This is the red system malfunction lamp, used on MHEV, PHEV and BEV versions. When it stays on, there is a fault in the electric propulsion system.

What to do:

• If the fault affects how your car performs, have it put right by a workshop straight away.
• Alternatively, switch off the engine and get help from a workshop.

12 V battery charge

This is the red 12 V battery charge lamp. When it stays on, the battery charging circuit is faulty, for example because of dirty terminals or a loose or broken alternator belt, or the 12 V battery charge level is low.

What to do:

• Clean and tighten the battery terminals.
• If the electric parking brake stops working, immobilise the car. With the eDSC6 automatic gearbox, move the gear selector to P.
• If the lamp stays on, or does not go out when you start the engine, have the fault put right by a workshop straight away, or switch off the engine and get help from a workshop.

Braking

This is the red braking warning lamp. It stays on when the brake fluid level in the braking circuit has dropped significantly, or when the electronic brake force distribution (EBFD) system is faulty. It can also come on steadily together with the Service warning light, with a message on the screen.

What to do:

If the brake fluid level has dropped:

• Take note of the warning, as action may be needed.
• Top up the brake fluid with fluid that meets the manufacturer's recommendations.
• If the problem continues, switch off the engine and get help from a workshop.

If the lamp comes on together with the Service warning light and a message:

• Stop somewhere safe and read the message on the screen.

If the EBFD system is faulty:

• Take note of the warning, as action may be needed.
• Switch off the engine and get help from a workshop.

Electric parking brake

This is the red electric parking brake lamp. When it is steady, the parking brake is applied. When it flashes, applying or releasing the parking brake is not working properly.

What to do:

If the lamp is steady:

• Release the parking brake before you drive off.

If the lamp is flashing:

• Park on flat, level ground.
• With an automatic gearbox, select P.
• Switch off the ignition and get help from a workshop.

Power steering

This is the red power steering lamp. When it stays on and you hear a beep, the power steering has a fault.

What to do:

• Stop somewhere safe.
• Switch off the engine and get help from a workshop.

Door(s) open

This is the red open door lamp. It stays on with a message telling you which door or the boot is not properly closed. Above 6 mph (10 km/h), you will also hear a beep.

What to do:

• Close the door or boot shown in the message properly.

Seat belts not fastened/unfastened

This is the red seat belt lamp. It lights up steadily or flashes, with a beep that gets louder, when a seat belt has not been fastened or has been unfastened.

What to do:

• Make sure every occupant fastens their seat belt.

AdBlue®

This is the AdBlue® lamp for BlueHDi diesel engines, which cannot run without AdBlue® fluid. When the AdBlue® level falls below the reserve, the lamp comes on when you switch on the ignition and the instrument panel shows how far you can drive before the engine can no longer be started. Messages will also remind you regularly to top up.

What to do:

If the AdBlue® level is below the reserve:

• Top up the AdBlue® when the range shown is between 1,500 and 500 miles (2,400 and 800 km).
• Keep an eye on the remaining range in the instrument panel.

If the AdBlue® tank is empty:

• The engine cannot be started until you top up the AdBlue® to at least the minimum level.

If You're Not Sure

If you are not sure what a red lamp means, or a lamp stays on after you have started the engine, stay calm and stop somewhere safe. Read any message on the screen, check your handbook and get help from a workshop if needed.

Red warning lamps on your Peugeot 308 should always be taken seriously. Knowing what each one means helps you react quickly and keep yourself and your passengers safe.

Related guides: Peugeot 308 III (2025-present) orange warning lights, Peugeot 308 III (2025-present) green and blue lights, Peugeot 308 Indicators: Red Warnings (general guide) and all Peugeot 308 guides.