Peugeot 508 Indicators: Red Warnings

A red warning lamp on your Peugeot 508's instrument panel means one thing: deal with it now. Some red lamps mean you should stop as soon as it's safe; others, like an unfastened seat belt or an open door, just need fixing before you carry on. This guide covers every red warning for the second-generation 508 Fastback and SW (2018 on), using the official Peugeot 508 owner's handbook as our reference.

Many 508s are plug-in hybrids, so alongside the usual engine warnings you'll find a few that only appear on the Hybrid and PSE versions.

Start with the quick-reference table, then scroll to the lamp you're seeing for the details.

Quick Reference

STOP Warning

A red triangle with an exclamation mark is the most serious warning on the dashboard. It never comes on by itself: it always appears with another warning lamp, a message on the display and a chime. The other lamp tells you which system is affected: the engine, brakes, power steering, automatic gearbox, or a major electrical fault.

What to do:

• Slow down and pull over as soon as it's safe. On a motorway, use the next exit or services if you can reach them safely. Otherwise stop on the hard shoulder (or the shoulder in the US) as a last resort
• Switch off the engine and don't try to drive on
• Read the message and note the second warning lamp, then call Peugeot Assistance or your breakdown provider (AA, RAC, Green Flag or AAA, for example)

Expect the car to be recovered on a truck rather than driven to the workshop.

Traction Battery Overheating

This lamp comes on together with the STOP warning, a message and a chime when the high-voltage traction battery is too hot. It's one of the few warnings where Peugeot tells you to get everyone out of the car.

What to do:

1. Stop as quickly as you safely can and switch off
2. Get all passengers out and move well away from the car, somewhere safe away from traffic
3. Call the emergency services if you see smoke or smell burning, then call Peugeot Assistance

Maximum Coolant Temperature

This warning means the cooling system is too hot. Depending on your instrument panel, you'll see either a thermometer symbol or the temperature gauge blocks turning red. Common causes are low coolant (often from a leak), a failed cooling fan or a radiator problem.

What to do:

• Pull over safely and switch off the engine
• Wait until the engine has cooled down completely. This can take an hour or more
• Then check the coolant level in the expansion tank and top up to the MAX mark if needed
• If the warning comes back, don't keep driving. Have the car checked

Safety first: never open the coolant cap while the engine is hot. The system is under pressure and can spray scalding coolant.

Engine Oil Pressure

The red oil can means a fault in the engine's lubrication system: the oil pressure is too low to protect the engine. This isn't the same as a routine "top up soon" reminder. Without oil pressure, serious engine damage can happen within minutes.

What to do:

• Stop as soon as it's safe and switch off the engine immediately
• Once the car has stood for a few minutes on level ground, check the dipstick. Low oil may be the cause, but topping up doesn't fix a pressure fault
• Don't drive on. Call for assistance and have the car taken to a workshop

System Fault

On hybrid, plug-in hybrid and electric versions, this lamp signals a fault in the electric drive system, either the electric motor or the traction (high-voltage) battery.

What to do:

• Stop safely, switch off and don't continue your journey
• Contact a Peugeot dealer or a workshop qualified to work on high-voltage systems
• Don't attempt any checks or repairs yourself. High-voltage components are dangerous to touch

12 V Battery Charge

This warning concerns the ordinary 12-volt battery and its charging circuit, not the high-voltage battery on electrified models. Typical causes are dirty or loose battery terminals, or a slack or broken alternator belt. If it's left, the battery will go flat and the car will lose electrical power.

What to do:

• Stop safely
• If the electric parking brake stops working, secure the car: engage a gear (manual), select P (EAT6), or chock a wheel (EAT8 or drive selector, depending on version)
• If you're comfortable doing so, check that the battery terminals are clean and tight
• If the lamp is still on after restarting, contact a dealer or workshop

Braking

The red brake symbol has two possible causes, according to the handbook:

• Brake fluid level has dropped significantly, often because of a leak or badly worn pads
• Electronic brake force distribution (EBFD) fault. On some versions this shows as the brake lamp together with the ABS lamp

What to do:

• Stop safely. Braking performance may be reduced
• If it's a fluid problem, top up with fluid that meets Peugeot's specification (it's listed in your handbook), but have the car checked before relying on the brakes
• For an EBFD fault, or if the warning returns, don't drive on. Call for assistance

On some newer models (for example the 308), the brake lamp can also signal a minor braking fault. In that case drive carefully and have it checked soon. The message on the display tells you which applies.

Traction Battery Fault

Shown together with the Service warning lamp and a message, this means a fault has been detected in the traction battery. Unlike the overheating warning, the handbook doesn't tell you to stop immediately, but it does say you should contact a dealer.

What to do:

• Contact a Peugeot dealer or qualified workshop as soon as possible
• If you notice loss of power or anything unusual, stop safely and call for assistance instead of driving on

Active Suspension Control

On models with Active Suspension Control, a steady warning means the system has a fault. Ride comfort and body control may be worse than usual.

Try a reset first:

1. Switch off the ignition and wait at least 30 seconds
2. Switch it back on and wait at least 5 seconds before starting
3. If the warning returns, book the car in with a dealer or workshop

Door(s) Open

A message shows which opening isn't properly shut: a door, the boot/tailgate or, on some models, the bonnet. Above about 6 mph (10 km/h) a chime is added so you can't miss it.

What to do:

• Pull over somewhere safe
• Close the opening shown on the display firmly
• If everything is closed but the warning stays on, a door or boot switch may be faulty. Have it checked, because it can also affect locking and the alarm

Seat Belt(s) Not Fastened / Unfastened

This lamp comes on, or flashes, with an increasingly loud chime when a seat belt hasn't been fastened or has been unbuckled on the move. Many versions also show which seat is affected.

What to do:

• Make sure everyone is buckled up. If someone needs to sort out a belt, stop safely first
• If the warning stays on with nobody in a seat, check that nothing heavy (a bag, for example) is on the seat cushion

Electric Parking Brake

If it's flashing:

• Park on level ground
• Engage a gear (manual) or select P (automatic or drive selector)
• Switch off the ignition and contact a Peugeot dealer or workshop

Charging Cable Connected (Plug-in Hybrid)

On plug-in hybrid and electric versions, this lamp comes on when you switch on the ignition with the charging cable still connected. If a message also appears, it's telling you that the car can't be driven until the cable is removed. This is a deliberate safety lock, not a fault.

What to do:

• Unplug the charging cable from the car
• Close the charging flap. The lamp should go out and the car will be ready to drive

If You're Not Sure

• Read the message. The text that appears with a lamp on the 508's display usually tells you exactly which system is affected
• Note what else is lit. Several warnings change meaning when they appear together with STOP or Service
• Photograph the dashboard before you switch off. It helps the dealer or your breakdown service diagnose the fault
• When in doubt, stop safely and call for help. It costs far less than a damaged engine or a collision

More Peugeot 508 Guides

See our orange warning lights, green and blue indicator lamps and what every 508 warning light means. For the bigger picture, read our Peugeot 508 review.

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