The Peugeot 307 suffers from serious brake and ABS faults (anti-lock braking system) that directly affect road safety. Breaking brake pedals, flashing warning lights and ABS failure due to corrosion on sensors are among the most frequently reported defects with this model. Cars from the period 2001–2008 in particular regularly show these issues. Below you can read which symptoms you can recognise, what the causes are and which steps you can take to solve or prevent these problems.
Recognisable symptoms of brake and ABS faults
Many owners of a Peugeot 307 report similar symptoms when they have brake and ABS problems. The ABS light on the dashboard is constantly on or flashes, often after restarting the engine. This points to communication problems between the ABS control unit and the BSI, the Body System Interface, the central control unit for various electrical systems.
In addition, the brakes sometimes do not bite properly. The car maintains its speed or slows down with difficulty; this often indicates contaminated sensors. In some cases an EPS fault also appears, the electronic power steering that assists the steering effort, combined with ABS warnings. This double fault is usually caused by corrosion on sensors as a result of road salt.
In more serious cases, the engine will not start without a functioning ABS unit. The fault message returns immediately, even after attempts to reset it. This makes diagnosis and repair urgent, because the car becomes unusable.
‘ Corrosion caused by road salt is a recurring problem with older Peugeot 307 models, especially after wet winters with a lot of gritting salt on the roads. ’
Common underlying causes of the faults
The problems with the braking system and ABS have several technical causes. A faulty ABS control unit sends incorrect data to the BSI. Dealers often advise complete replacement based on the chassis number, because the units are model-specific.
Wheel and camshaft sensors regularly become contaminated with iron filings or corrosion. This causes open circuits in the electrical connection. The front wheels are the most vulnerable here due to their position and exposure to road salt. The wiring and connectors can also cause problems due to loose pins, poor earth connections or CAN bus faults (communication network between control units) between the ABS unit and BSI.
Electrical relays sometimes fail, so the ABS pump is no longer actuated. In that case the pump must be replaced completely. Corrosion caused by road salt is a recurring problem with older Peugeot 307 models, especially after wet winters with a lot of gritting salt on the roads.
Diagnosis as the starting point for targeted repair
Start by reading fault codes using an OBD scanner (diagnostic tool for fault codes). These codes indicate which component or system is causing the issue. Then check all earth connections, supply voltages and plug connections. Measure this dynamically by connecting a test lamp in parallel, so you can observe any voltage drop during operation.
Also measure the wiring between the BSI and the ABS control unit. A fault in this communication line blocks the entire system. Pay attention to damaged cables, broken-through insulation or moisture in connectors.
Practical repair tips for DIYers
If the wheel speed sensor is contaminated, you can clean it yourself. Remove the wheel, the brake caliper and the carrier. Take off the hub or disc and clean the wheel speed sensor thoroughly with brake cleaner. Avoid leaving the brake caliper hanging from the hydraulic line, as this can damage the hose.
With a contaminated camshaft sensor, remove iron filings and use a multimeter to check whether the sensor has continuity. This is a quick check that can rule out many problems. Replacing the ABS relay is also simple and in some cases completely clears the fault message.
With a defective ABS control unit there are two options. Desolder the EEPROM chip from the defective unit and solder it into a new unit, or temporarily switch off the ABS via telecoding. This last option is an emergency measure and not suitable as a long-term solution.
To prevent corrosion, rinse the underside of the car regularly after winter. Coat connectors with conductive paste to keep out moisture. This significantly extends the service life of sensors and wiring.
Overview of problems and repair options
- ABS light on: scan fault codes and clean wheel speed sensors
- Wiring defective: measure pins with a multimeter and check the connection between BSI and ABS
- ABS unit defective: have it overhauled or replace the unit completely
- Corrosion on sensors: clean sensors and coat connectors with paste
Owners’ experiences and practical advice
Owners share their experiences with these problems online. The ABS pump on the left-hand front side is often mentioned as the culprit. A new pump, specific to the correct chassis number, in some cases also solves exhaust gas faults related to the ABS electronics.
Iron filings on the camshaft sensor regularly turn out to be the cause of faults. After cleaning, the system often works perfectly again. Road salt in winter causes corrosion on EPS and ABS sensors, especially on 2006 models.
Dealers often advise replacement of the complete unit, which is expensive. Many owners therefore opt for overhaul or replacement of just the sensor, which is cheaper and often just as effective.
Breaking brake pedals and recall campaigns
In addition to electronic problems, there are reports of brake pedals snapping on the Peugeot 307. This is a mechanical defect that carries immediate safety risks. Check with the dealer whether there is a recall for your car. Not all production periods or chassis numbers are covered by a recall, but it is advisable to ask.
If you are in doubt about the condition of the brake pedal, have it explicitly checked during the MOT or a service. A cracked or weakened pedal must be replaced immediately to prevent dangerous situations.
‘ An OBD scan shows stored fault codes, even if they are no longer active. ’
Test drive and checks when buying a used car
If you are buying a used Peugeot 307, check the brakes and ABS thoroughly during a test drive. Watch out for flashing or illuminated warning lights on the dashboard. Test the braking performance at different speeds and check whether the car slows down evenly.
Ask the seller about known brake or ABS faults and any repairs carried out. If in doubt, have the car inspected by a garage beforehand. An OBD scan shows stored fault codes, even if they are no longer active. This provides insight into previous problems.
Prevention and regular maintenance
Regular maintenance prevents many problems. Rinse the underside of the car after winter to remove brine and road salt. Inspect sensors during the MOT inspection and have them cleaned if they are contaminated. Also check the condition of the wiring and connectors, especially around the wheels and the ABS unit.
For persistent faults, have the ABS control unit overhauled for a long-lasting solution. Overhaul is often cheaper than complete replacement and solves software problems in the unit. For complex electronic problems, use a specialist garage with experience of Peugeot models.
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Frequently asked questions
The Peugeot 307 has common brake and ABS problems such as ABS, Stop and EPS warning lights that illuminate or flash spontaneously, sometimes affecting braking performance or engine starting. Typical causes include a defective or internally corroded ABS control unit, contaminated or salt-damaged wheel and camshaft sensors, and poor wiring or connectors (earth/supply, CAN bus) between the ABS unit and BSI. Failing relays and pump components in the ABS unit also occur regularly, especially on older 307 models that have been heavily exposed to moisture and road salt. As a result, poorly biting brakes, permanently illuminated ABS lights and combined EPS/ABS faults can occur.
Start by reading fault codes with an OBD scanner and make a note of ABS, EPS and brake-related codes in particular. Then visually inspect the wheel speed sensors and wiring for corrosion, dirt (such as iron filings) and loose or damaged plugs, especially at the front wheels. Measure earth and power supply at the ABS unit and the wiring between ABS unit and BSI with a multimeter to rule out breaks or poor connections. If sensors and wiring are in order, have the ABS control unit professionally tested or overhauled, as this is often the source of persistent faults.
On this model, defective ABS sensors are often caused by corrosion and dirt (iron filings, salt residues) on or around the wheel speed sensors and their plugs, especially after wet winters. In addition, broken wires or poor earth/supply in the wiring and connectors between the ABS unit and BSI are very common. Brake pressure problems are usually related to defective or sticking ABS pumps and relays, which disrupt pressure build-up in the system. Internal defects or wear in the ABS control unit itself can also cause both ABS faults and irregular brake pressure.
Possible repair options for brake and ABS problems on a Peugeot 307 include cleaning or replacing ABS/wheel speed sensors, repairing or replacing wiring and connectors, and having the ABS control unit/pump overhauled or completely replaced. Relays and any sticking or unevenly worn brake components (discs, pads, calipers) can also be checked and replaced if necessary. On average, cleaning or replacing a single sensor often costs €75–€200, depending on labour and parts. Overhaul or replacement of the ABS unit/pump can range from around €300–€900, depending on whether you choose overhaul or a new dealer unit.
Yes, regularly check brake pads, discs and brake fluid for wear or leaks and have the brake fluid replaced on time according to the service schedule. During a tyre change or service, carefully clean the wheel speed sensors and their surroundings with brake cleaner to remove dirt and iron filings. During the winter, after driving on salted roads, occasionally rinse the underside and wheel arches to limit corrosion on sensors, plugs and the ABS unit. Visually check plugs and wiring of the ABS unit for corrosion and make sure they are firmly connected; if in doubt, have fault codes read out.