A car engine is a complex mechanism where clock synchronization is critical for stable operation. On Skoda Fabia, especially with gasoline engines of the EA111 series and diesel TDI, one of the common reasons for a sudden stop is the failure of the crankshaft position sensor (CPS). This small but vital element transmits shaft rotation information to the engine control unit, allowing the ignition and injection system to operate correctly.
Ignoring signs of malfunction can lead to the car simply not starting at the most inopportune moment. Many owners Skoda Fabia are faced with a situation where the car stalls while driving or refuses to start after stopping, and often the reason lies precisely in this sensor. Understanding the principles of operation of the device and the ability to replace it yourself will save significant money on car repair services.
Symptoms of a faulty crankshaft sensor
A DPKV failure can be recognized by a number of characteristic signs that appear during engine operation. The most obvious symptom is the inability to start the engine: the starter turns properly, but the system does not see the shaft speed and does not supply a spark or fuel. In some cases, the engine may become unstable, jerk at idle, or lose power when accelerating.
It is important to pay attention to the behavior of the car when the temperature rises sharply. Often the sensor begins to malfunction precisely when it heats up, which is why the car stalls after a long trip and does not start until it cools down completely. This is due to a change in the physical properties of the magnet or winding inside the housing crankshaft sensor under the influence of high temperature.
The indicator on the dashboard may come on Check Engine. However, in some cases, especially on older firmware versions, the error may not be recorded if the failure is short-term. For accurate diagnosis, you need to use an OBD2 scanner and read the error code, which usually looks like P0335 or P0336.
- ๐ซ Complete engine failure to start with a working starter.
- ๐ Unstable operation at idle and jerking when driving.
- ๐ฅ Sudden engine stop after warming up to operating temperature.
Reasons for failure and selection of spare parts
The main cause of failure is mechanical damage or natural wear of the internal winding. The sensor is located in an area of โโhigh temperature and vibration, which over time leads to the destruction of wire insulation or changes in the characteristics of the magnet. It is also common for the sensitive part of the sensor to become contaminated with metal shavings that enter from the engine through the gap.
When selecting a new part for Skoda Fabia You should give preference to original components or proven analogues from well-known brands. Cheap Chinese copies often have a low-quality magnetic system, which is why they can fail after a few months of use or give false signals, causing errors in the operation of the ECU.
Incorrect installation of the previous sensor can also cause its rapid death. If the gap between the sensor and the flywheel ring gear was set incorrectly, or the fastening was not tightened enough, vibration could lead to mechanical destruction of the housing. The optimal gap is 0.5โ1.0 mm and is ensured by the design of the sensor itself without adjustments.
โ ๏ธ Attention: Never install a sensor with a damaged housing or damaged wire integrity, as this will lead to rapid failure of the new part or even a short circuit in the circuit.
Codes of original spare parts for popular engines 1.2 MPI or 1.4 TSI may vary depending on year of manufacture. It is recommended to check the part number against the vehicle's VIN code to avoid mistakes when purchasing. Often in catalogs there are numbers starting with the prefix 06H or 03C, which indicates belonging to a specific series of motors.
- ๐ง Use only certified spare parts from Bosch, Hitachi or original VAG.
- ๐ Check the integrity of the connector and wire before purchasing a new part.
- ๐ Check the part number with your vehicle's VIN in the catalogue.
- 1.2 MPI (3 cylinders)
- 1.4 MPI (4 cylinders)
- 1.6 MPI (4 cylinders)
- 1.4 TSI (turbo)
- 1.9 TDI (diesel)
Necessary tools and preparation
To perform work on replacing the crankshaft position sensor, you will need a minimum set of tools. In most cases, a standard set of sockets, screwdrivers, and perhaps an extension cord will suffice to get into hard-to-reach areas. Special pullers or complex fixtures are usually not required, since the sensor is mounted on a single bolt.
Before starting work, it is necessary to ensure safe access to the engine. On Skoda Fabia front-wheel drive sensor is often located at the bottom, next to the flywheel or pulley crankshaft. You may need to remove the engine's lower protective shield or even the wheel for easy access.
Be sure to turn off the battery's negative terminal before starting work. This will prevent accidental short circuits when the electrical connector is disconnected and will protect the electronic control units from voltage surges.
It is also worth preparing the rags and brake cleaner to clean the place of installation of the sensor from dirt and oil. A clean surface ensures the correct clearance and no vibrations. Donโt forget to check the status of the connection connector โ if the contacts are oxidized, they need to be cleaned or replaced entirely.
- ๐ A set of carob keys and heads (most often 8 or 10 mm).
- ๐งผ Brake cleaner and degreasing rag.
- ๐ฆ Lights for lighting the working area under the engine.
โ๏ธ Preparing to replace the sensor
Step-by-step replacement instructions
The replacement process begins with finding the sensor itself. On the engine. 1.2 MPI It's usually down on the gearbox side, in the flywheel area. On diesel versions, the place may differ, but the principle of search remains the same: you need to find an element aimed at the crankshaft gear disc.
Disconnect the electrical connector by pressing the lock. Be careful not to break the plastic latch. After that, unscrew the fastening bolt that holds the sensor. It is usually about 70-80 mm long and requires the use of an extension cord.
Carefully remove the old sensor. If it is boiled or contaminated, do not use excessive force so as not to damage the wiring. Inspect the seat and make sure there is no metal shavings or other foreign objects. Wipe the installation site with a cleaner.
Install a new sensor, making sure it has fallen into place without skewing. Tighten the fastening bolt with the recommended tightening moment, which is usually around 10 Nm. Do not pull the bolt, as the sensor case may burst. Connect the electrical connector before clicking.
After assembly, check the engine operation. Start the engine and make sure that it works smoothly, without dips and extraneous sounds. If there's a mistake P0335 The problem may be in the wiring or the control unit itself, but in 95% of cases, replacing the sensor solves the problem.
What to do if the sensor cannot be removed?
If the sensor is boiling, try to sway it slightly from side to side, without making a sharp effort. Sometimes it helps to treat penetrating lubricant type WD-40 around the case, but make sure that it does not get on the electrical contacts. Do not hit the sensor with a hammer - it will destroy its magnetic system.
Before installing a new sensor, check the condition of the flywheel's cogwreath. If there are chips or strong production on the teeth, the sensor will give incorrect readings even when it is working.
Specifications and specificity of engines
Various modifications Skoda Fabia They are equipped with different types of engines, which affects the location and design of the sensor. For example, on the atmospheric engines of the series EA111 The sensor has a single design, whereas on turbo versions TSI It can be integrated into another node or have a different type of connector.
The table below shows the main characteristics and location of the sensor for the most common engines found on the market.
| Engine | Volume (l) | Installation features | Sensor type |
|---|---|---|---|
| 1.2 MPI | 1.2 | Downstairs, from the checkpoint. | Inductive |
| 1.4 MPI | 1.4 | Side by the flywheel. | Inductive |
| 1.4 TSI | 1.4 | At the top of the block (rarely) | Magnetic |
| 1.9 TDI | 1.9 | Downstairs, next to the clutch basket | Inductive |
| 1.6 MPI | 1.6 | Down, access through the subframe. | Inductive |
The peculiarity of inductive sensors is that they do not require external power, generating a signal due to a change in the magnetic field when passing the crown teeth. This makes them reliable but sensitive to gaps. Any deviation in the distance to the teeth of the crown can lead to loss of signal.
On diesel engines Common Rail The requirements for signal accuracy are even higher, since the moment of fuel injection depends on this. Therefore, Skoda Fabia With diesel, the use of non-original sensors is especially not recommended, since the error can lead to increased fuel consumption and exhaust smoke.
The accuracy of the gap between the sensor and the flywheel crown is a critical factor for the stable operation of the engine at all modes.
Diagnostics of wiring and electrical circuit
If the replacement of the sensor did not bring results, it is necessary to check the electrical circuit. A wire break or poor contact in the connector can mimic a fault in the sensor itself. Use a multimeter to check the integrity of wires from the sensor to the ECU connector.
Check the resistance of the sensor winding. For most models Skoda Normal resistance ranges from 400 to 1000 Ohms, but the exact values are always specified in the specification for a particular engine. If the resistance is infinitely large or zero, the sensor is faulty.
It is also worth paying attention to the state of shielding wires. The screen protects the signal from interference from the ignition system and the generator. Damage to the screen can lead to false pulses, which the ECU interprets as engine failures.
โ ๏ธ Warning: When checking with a multimeter, do not allow the probes to touch each other when ignition is connected, so as not to burn fuses or control units.
If the wiring is in order, the problem may be in the engine control unit itself (ECU). However, this is extremely rare. Most often, the problem lies in the oxidation of contacts in the sensor connector, which is easily eliminated by cleaning the contacts and applying dielectric lubrication.
- ๐ Check the resistance of the sensor winding (usually 400-1000 ohms).
- ๐ Check the connector for oxidation and corrosion.
- ๐ Check the integrity of the shielding wire braid.
Cost of work and prevention
The cost of replacing the crankshaft sensor depends on the chosen method: independent work or contacting the service. If you decide to do everything yourself, the cost will only be the cost of a new part, which varies from 1500 to 4000 rubles depending on the brand.
In the car service, the replacement work will take about 30-60 minutes. The cost of services of the master can be from 1000 to 3000 rubles. In dealerships, the price will be higher, but you will get a guarantee for work and use only original spare parts.
Prevention of malfunctions is a regular check of the sensor condition during planned maintenance. Clean it of dirt and oil, check the reliability of the attachment and the integrity of the connector. This will help to avoid sudden breakdowns on the road.
Keep in mind that timely replacement of the sensor is cheaper than engine repair, which may be required during long-term operation with a faulty synchronization system. Ignoring the symptoms can lead to the fact that the engine will work in an abnormal mode, which is fraught with serious consequences.
Regular cleaning and checking of the sensor attachment with planned maintenance significantly prolongs its service life.
Why does the engine only stop hot?
When heated, materials expand. If there are microcracks in the winding or deformation of the magnet inside the sensor, the contact may be broken when heated, and the signal disappears. After cooling, the materials are compressed and the work is restored.
Is it possible to drive with a faulty crankshaft sensor?
No, operating a car with a faulty sensor is impossible. The engine will either not start or will work with serious interruptions, which can lead to failure of the catalyst or other components.
Do I need to do an adaptation after replacing the sensor?
In most cases, adaptation is not required. The control unit automatically picks up a new signal. However, if the error does not erase, adaptations may need to be reset through a diagnostic scanner.
How often should the crankshaft sensor be replaced?
The sensor has no regulated replacement period and serves almost the entire life of the car. Replacement is made only in case of actual breakdown or detection of malfunction during diagnosis.
Does the quality of the fuel affect the sensor?
The quality of the fuel does not directly affect the operation of the sensor. However, poor-quality fuel can lead to engine contamination and an increase in the amount of metal shavings that can settle on the sensor and disrupt its operation.