What Do Peugeot 508 Warning Lights Mean? Service and Gauge Guide

The Peugeot 508's instrument panel constantly reports on the car's health: when the next service is due, whether the oil level is right, how hot the engine is and, on BlueHDi diesels, how far you can go before the AdBlue runs out. Plug-in hybrids add power and charge readouts.

This guide explains those readouts on the second-generation 508 Fastback and SW (2018 on) and what to do when they change, based on the official Peugeot 508 owner's handbook. If you're trying to identify a coloured warning lamp, our red and orange guides are the place to go.

Service Indicator

The service indicator shows when the 508's maintenance is due, in distance (kilometres or miles) and time (months or days). The alert is triggered by whichever limit is reached first, and the service information is shown on the instrument panel. Depending on the version, the distance recorder line shows the distance driven since the service or deadline passed, preceded by a "-" sign. An alert message also tells you how many kilometres or how much time remain until the next service is due. The value is calculated from the distance covered and the time since the last service, and the alert can also be triggered by the due date.

What to do:

The service spanner shows different states:

If it comes on briefly when you switch on the ignition, the next service is between 1,000 and 3,000 km away.

If it stays on steadily, the next service is less than 1,000 km away and the car should be serviced as soon as possible.

If it flashes with the ignition on and then stays on steadily, the service is overdue and the car should be serviced as soon as possible.

Resetting the Peugeot 508 Service Indicator

The service indicator can be reset after every service. If you service the car yourself, switch off the ignition, then press and hold the button on the end of the lighting control stalk while pressing the START/STOP button once without pressing the brake pedal. A temporary display window appears and a countdown starts. Release the button when the display shows "=0", and the spanner symbol disappears. If you disconnect the battery terminals after doing this, lock the car and wait at least 5 minutes, otherwise the reset won't be registered.

Peugeot 508 Service Information Reminders

You can view service information from the Settings > Vehicle application on the touchscreen, then by selecting Safety > Diagnostics. It shows the service information and when maintenance is due, helping you keep track of the car's needs and keep it running at its best.

Engine Oil Level Indicator

Depending on the version, the 508 has an electric engine oil level gauge. When you switch on the ignition, the oil level status is shown as a message on the instrument panel for a few seconds after the service information. For an accurate reading, the car must be on level ground and the engine must have been switched off for at least 30 minutes.

What to do:

If the oil level is low, the Service warning lamp comes on with an audible signal and a message telling you to top up the oil. If a dipstick check confirms the low level, you must top up to avoid engine damage.

Is There a Fault with the Peugeot 508 Oil Level Measurement?

If the instrument panel shows "Invalid oil level measurement", there is a fault with the oil level measurement. Contact a PEUGEOT dealer or qualified workshop. With the electric gauge faulty, the oil level can no longer be monitored electronically, so check it with the dipstick in the engine compartment.

Checking the Engine Oil Level

For more on checking the engine oil level, see the relevant section of the owner's handbook. Doing it properly helps the car run well and the engine last.

Coolant Temperature Gauge

The coolant temperature gauge shows the engine's operating temperature and is divided into two zones:

Zone A: the temperature is normal and correct, with the engine in its ideal operating range.

Zone B: the temperature is too high. The related warning lamp and the red STOP warning lamp come on, with a message and an audible signal.

What to do:

If the gauge reaches zone B, the car is showing signs of overheating. Here's what to do:

1. You must stop the car in the safest conditions possible. Pull over safely, watching the traffic and road conditions.
2. Don't switch the engine off immediately; wait a few minutes. This helps avoid damage from sudden cooling after the engine and cooling system have overheated.
3. After switching off the ignition, carefully open the bonnet and check the coolant level. Take great care working under the bonnet while the engine is hot: hot parts and fluids can cause serious burns.
4. Check the coolant level as described in the owner's handbook.

The cooling system is vital for preventing overheating and keeping the engine running efficiently. Regular checks and maintenance are important for the car's long-term health.

AdBlue® Range Indicators (BlueHDi)

The 508's BlueHDi diesel engines have a Selective Catalytic Reduction (SCR) emission control system and a Diesel Particulate Filter (DPF) to treat exhaust gases, and these systems use AdBlue® fluid to keep emissions down. When the AdBlue® reserve falls from 2,400 km to 0 km of range, a warning lamp comes on showing the estimated distance you can drive before the engine is prevented from starting, and this is shown every time you switch on the ignition.

What to Do When AdBlue® Is Running Low

As the AdBlue® level drops to critical, a series of warnings tell you to refill. When the tank is completely empty, a system prevents the engine from starting, and the car can't be started until the minimum level of AdBlue® has been added. The warnings and remaining ranges are:

Between 2,400 km and 500 km: warnings telling you to top up.

Between 800 km and 100 km: warnings stressing that a refill is urgent.

Between 100 km and 0 km: warnings that at least 10 litres of AdBlue® must be added before the engine can be restarted.

After Refilling with AdBlue®

The refill may not be detected straight away. It can take a few minutes of driving for the system to recognise it.

SCR Emission Control System Fault

When a fault is detected in the SCR system, the warning lamps come on with the message "Emissions fault" and an audible signal. If the fault is temporary, the warning goes out on the next journey after the SCR system's self-diagnostic check. But if the fault is still present after 50 km of driving, the SCR fault is confirmed: the AdBlue warning lamp flashes and the distance after which the engine won't start is shown.

Starting Prevented

If the message "Emissions fault: Starting prevented" is displayed, a serious SCR fault is preventing the engine from starting. Contact a PEUGEOT dealer or qualified workshop.

Power Indicator (Plug-in Hybrid)

On the 508 plug-in hybrid, the power indicator shows the power the car is demanding in real time, helping you use energy efficiently. It has three zones:

POWER: the petrol engine and the electric motor(s) (depending on version) are working together under high power demand. The needle moves here in more dynamic driving, especially when high performance is needed.

ECO: the best use of energy. The needle is here when you drive smoothly using the petrol engine or electric motor, when driving on electric power and when the petrol engine is used optimally. It also includes a threshold that helps you adjust how you accelerate to stay in electric mode.

CHARGE: energy is being recovered to partially recharge the traction battery. The needle moves here when slowing down, for example when you lift off the accelerator or brake, showing regenerative braking is returning energy to the battery.

Driving Efficiently with the Peugeot 508 Hybrid Power Indicator

By showing energy use in real time, this indicator helps you build better-informed, more efficient driving habits, making the most of electric mode, cutting fuel consumption and lowering CO2 emissions.

Charge Level Indicator (Plug-in Hybrid)

On the 508 plug-in hybrid, the traction battery charge level indicator shows how far the car can travel on electric power. When the car is switched on, the battery's current charge and the estimated electric range are displayed permanently on the instrument panel.

Charge Level Indicator Features

Charge level: the battery's current state of charge, indicating how long or how far the car can run in electric mode.

Range: the estimated distance the car can cover in electric mode on the current charge. It can vary depending on many factors.

Manual Test

The manual test lets you check the 508's various indicators and display the list of alerts. It gives a quick, complete overview of the car's condition and helps catch potential problems early. You can reach it easily from the touchscreen.

Start the Manual Test

1. Go to the Settings > Vehicle touchscreen application.
2. Select Safety > Diagnostics.

During the manual test, the instrument panel shows:

Tyre pressures: the current pressure of each tyre.

Engine oil level: depending on the engine type.

Next service due: when the car next needs a service.

AdBlue® and SCR system: for BlueHDi diesel engines, the AdBlue® level and the driving range related to the SCR system.

Active alerts: any warning currently active on the instrument panel.

This information is also displayed automatically every time you switch on the ignition, so you can review the car's critical status quickly each time you start it.

Odometer

The odometer measures the total distance the 508 has covered since it was first registered, giving you important information about the car's overall use.

Odometer Features

Always visible: with the ignition on, the total distance is shown continuously, so you can easily keep track of the car's use.

After switching off: the odometer stays visible for 30 seconds after the ignition is switched off.

With the door open: the reading is also shown when the driver's door is open and the car is locked or unlocked, so you can check it even as you get out.

Changing the Distance Units

When travelling abroad, you may need to switch the distance units (kilometres or miles) to match the official units of the country you're in (km/h or mph). Change them in the touchscreen's configuration menu while the car is stationary.

Odometer on Plug-in Hybrid Models

On the 508 plug-in hybrid, the odometer can only be reached through the trip computer, which also gives detailed information on the car's total use, including electric driving and petrol engine use. See the relevant section of the owner's handbook for more about the trip computer.

Lighting Dimmer

The lighting dimmer lets you manually adjust the brightness of the instruments and controls to suit the light outside, optimising the visibility of screens and controls in different conditions for both comfort and safety.

Adjusting the Lighting Dimmer

You can configure the dimmer easily from the touchscreen:

1. Go to the Settings > Brightness touchscreen application.
2. Press the slider in the "Cockpit" category, or move it to the brightness level you want.
3. This personalises the brightness of the screens and controls to suit your eyes and visibility needs, which makes driving more comfortable at night or in changing light.

Key Points to Remember

• A flashing or red service, oil or temperature readout always takes priority over everything else on the panel
• Check the oil level with the dipstick if the electronic gauge reports a fault, rather than relying on the gauge
• Don't let a BlueHDi diesel run out of AdBlue: once the tank is empty, the engine won't restart
• Book your service when the spanner first appears rather than waiting for it to flash

For the warning lamps, see our 508 red warning lights, orange warning lights and green and blue indicator lamps guides, and learn your way around the screens in How to Check Peugeot 508 Warning Lights. For the car as a whole, read our Peugeot 508 review.

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