The lack of a starter reaction to the key rotation in the ignition lock often indicates battery discharge or oxidation of the terminals, which is the most common reason for the inability to start the engine. Car owner Renault Logan in such a situation, the first thing to check the voltage at the terminals of the current source and the density of the contacts. If the starter turns, but the engine does not catch, the problem shifts to the area of fuel supply or spark formation. Depending on the specific modification of the power unit and operating conditions, the algorithm of actions can vary significantly, requiring a careful analysis of the accompanying symptoms.
Check if the oil pressure bulb is burning immediately after the ignition is turned on. If the indicator does not light up, there may be a problem in the power supply of the onboard network.
Low ambient temperatures make the ignition process much more difficult, especially if low-quality fuel is used or engine oil is out of season. Frozen condensate in the exhaust system or ice crust on spark plugs are able to completely block the engine even with serviceable main systems. Diagnostics in winter requires the exclusion of icing of fuel lines and checking the state of high-voltage wires. Ignoring these factors can lead to a waterstrike or breakage of the starter when forced scrolling attempts.
⚠️ Warning: Do not try to start the car from the pusher if you have an automatic transmission installed DP0/AL4 Or a robotic transmission. This will lead to serious mechanical damage to the transmission units.
Diagnostics of the electrical system and battery
The first step in restoring the vehicle’s performance is to thoroughly check the battery status. The voltage at the terminals of a serviceable battery should be at least 12.5 Volts at rest. When trying to start, the voltage should not fall below 9-10 volts, otherwise the starter will not be able to develop the necessary revolutions to create a compression. Oxidized contacts often cause loss of current, so they must be cleaned to a metallic shine and tighten the fasteners.
If the battery is completely discharged, you can use the method of “lighting” from another car. This requires special start wires with a cross section corresponding to the start current. It is important to observe the polarity of the connection: first, the plus terminals are connected, then the donor's minus terminal is connected to the mass of the receiving car (for example, to the engine block), and not to the minus of the discharged battery. This safety rule avoids the sparking of hydrogen vapors that can be released from the battery.
In some cases, the problem lies not in the battery itself, but in poor contact of the body mass with the engine. Weakening or corrosion of the main mass wire leads to the fact that the starter receives insufficient current or does not receive it at all. Integrity verification cable-channel And the places of fastening of wires allows you to identify hidden breaks or oxidation. Often enough to tighten the bolt of the wire attachment to the body or engine, so that the system worked normally.
Problems with the fuel system and gasoline supply
When the starter confidently rotates the crankshaft, but the engine does not start, the most likely reason is the lack of fuel supply to the cylinders. In cars. Renault Logan for the supply of gasoline is responsible electric fuel pump located in the tank. When turning on the ignition, before starting the starter, you need to listen: in the area of the rear seats, a short-term hum of the working pump should be heard, creating pressure in the ramp. The absence of this sound indicates a malfunction of the pump, the combustion of its fuse or control relay.
Pressure in the fuel ramp.
The normal fuel ramp pressure for 1.4 and 1.6 engines is about 3.5-4 bar. Checking is carried out through a special connection on the ramp using a pressure gauge.
Fullet clogging is also a common cause of difficult start-ups, especially if the vehicle was fuelled with questionable quality. The filter element, clogged with dirt and impurities, creates a high resistance to the flow of gasoline, and the pump is not able to pump the necessary volume of liquid to create a mixture. Replacement of the fuel filter is a routine procedure that should be carried out regularly. In addition, in winter, water can form in the tank, which freezes in the fuel line, completely blocking the access of gasoline to the engines.
⚠️ Warning: Do not attempt to disassemble a fuel pump or highway in an enclosed space or near an open flame. Gasoline vapors are explosive even at low concentrations.
To check the availability of fuel, you can press the fuel ramp connection spool (preliminarily substituted the container and observing fire safety measures). If gasoline hits a strong jet, then there is a supply, and the problem should be looked for in the nozzles or pressure regulator. If the fuel only drips or does not go at all, the malfunction is in the module of the gas pump or the highway to the ramp. Adjustment The fuel pressure in such systems is replaced by a regulator that is often incorporated into the pump module.
Ignition system and candle condition
Sparking is the second key factor for successful internal combustion engine start-up. Cars. Renault Logan ignition coils are used, which can fail alone or in groups. To check, you need to twist the candle, put a high-voltage wire tip or coil on it, press the threaded part to the “mass” of the engine and spin the starter. The presence of a powerful blue spark indicates the serviceability of the ignition system as a whole.
If the spark is weak, reddish or absent at all, it is necessary to check the condition of the spark plugs. Black colored nagar indicates a rich mixture or problems with combustion, white plaque - about overheating or poor mixture. The gap between the candle electrodes must meet factory specifications, usually 0.7-0.8 mm for Logan gasoline engines. Wear of the electrodes increases the gap, which requires a higher voltage for breakdown, which the standard coil cannot provide.
| Fault type | Symptom | Test method | Solution |
| :--- | :--- | :--- | :--- |
| Discharged battery | Starter does not spin or spins slowly | Multimeter voltage measurement | Charging or replacing battery |
| Failed gas pump | No pump hum when ignition is activated | Listen at the tank, measure pressure | Replacement of pump or fuse |
| Problems with candles | Engine is Troit, no spark | Visual inspection, spark check | Candle replacement |
| Immobilizer error | Blinks key bulb, starter blocked | Monitoring indicator on panel | Key flashing or ECU |
It is also important to check the integrity of the high-voltage wires and the condition of the tips of the ignition coils. Cracks on the insulation of the wires can lead to a "breakdown" of the spark on the engine body, especially in wet weather. In such cases, the spark follows the path of least resistance without hitting the cylinder. The use of quality components and the maintenance of the underhood space in cleanliness and dryness minimizes the risks of such malfunctions. Switch The crankshaft position sensor also plays a critical role in the moment of spark formation.
Effects of immobilizer and electronic locking
Modern cars Renault Logan equipped with a standard immobilizer system, which blocks the start of the engine in the absence of recognition of the chip in the key. If the indicator flashes in the form of a red car or key when you turn the key on the dashboard, this is a direct signal that the system does not see the mark. In this mode, the starter may either not respond at all, or scroll the engine, but the fuel supply and sparks will be blocked programmatically.
☑️ Checklist of check of immobilizer
Often the cause of failure is a discharged battery in the key fob itself. The signal becomes too weak, and the immobilizer antenna located around the ignition lock cannot read the code. In emergency cases, you can try to bring the key as close as possible to the lock or a special place on the steering column. If the spare key is working properly, the problem is clearly in the main key chip or its power element.
There are situations when the system "forgets" the keys due to voltage surges in the on-board network or a deep battery discharge. In this case, a procedure for “training” keys using special diagnostic equipment or a dealer scanner is required. It is difficult to carry out this procedure without skills and tools. Attempts to bypass the immobilizer by installing decoys can lead to unstable engine operation and problems with other electronic units.
Starting the engine in the cold season
Winter engine start-up Renault Logan requires a certain sequence of actions to avoid harming the engine and increase the chances of success. Before turning on the starter, it is recommended to “heat up” the battery, briefly turning on the high beam headlights for 10-15 seconds. This will trigger chemical reactions in the electrolyte and increase the battery’s current output. After that, you need to squeeze the clutch (on the mechanics) and turn on the ignition, giving the fuel pump to pump pressure into the ramp.
Winter oil
For winter operation, it is recommended to use motor oils with a viscosity of 5W-30 or 5W-40. They keep fluidity at low temperatures, making it easier to turn the crankshaft.
If the engine did not start from the first time, you should not turn the starter for a long time. The optimal cycle of the starter is 5-7 seconds, after which a break of at least 30-40 seconds is needed to restore the battery charge and cool the windings. Prolonged work of the starter without flashes leads to the "filling" of spark plugs with gasoline. In this case, the spark stops skipping, as the wet electrodes close to the mass. To dry candles, you can press the gas pedal into the floor (cylinder blowout mode) and spin the starter for several seconds without fuel supply.
When using preheaters or auto-starts, it is important to monitor the state of the exhaust system. Short trips in winter do not allow the muffler to warm up to the temperature of condensate evaporation, which leads to the formation of ice stoppers. Blocking the exhaust gases creates back pressure that prevents the engine from starting or causes it to immediately stall. Regular inspection and cleaning of the exhaust system from water and ice is a mandatory procedure for owners operating cars in the cold.
Emergency launch and precautions
In critical situations, when standard methods do not help, owners resort to emergency start-up methods. For cars with a manual transmission, it is possible to start “from a pusher” or tow. To do this, you need to turn on the ignition, accelerate the car (by push or tow) to a speed of 10-15 km / h, turn on the third gear and sharply release the clutch. After a flash in the cylinders, the clutch must be squeezed out again so that the engine does not stall.
The main conclusion: Successful launch depends on three factors: compression, spark and fuel. If two of the three are present, the engine will work.
However, it is worth remembering that the frequent use of the "pusher" method can adversely affect the condition of the catalyst and the timing belt due to jerks. In addition, on cars with automatic transmission, this method is strictly prohibited, as it can lead to failure of the hydraulic transformer and frictions. In such cases, only a search for a fault in the electrician or the use of a starter (booster) remains.
When any manipulations with the ignition system and fuel system must comply with fire safety rules. Gasoline is easily ignitable, and a high-temperature spark can become a source of fire. All work should be carried out in a well-ventilated room or in the open air. If you are not confident in your abilities or the diagnosis shows complex electronic errors, it is better to contact qualified specialists of the service center.
Why doesn't Logan start in the cold when the battery is new?
Even a new battery may not be able to run if the oil is not season-appropriate, candles have a large amount of sodium or water is present in the fuel. Also check the air filter – if it is clogged with snow or ice, the engine will “suffocate.”
What if the car does not start after replacing the battery?
When replacing the battery, the throttle adapter or immobilizer settings could be lost. Try to drop the terminals for 15 minutes. If it did not help, perhaps during the installation, contacts were confused or the fuel pump fuse was damaged.
How do you know if the gas pump is dead and not the filter?
If you do not hear the characteristic hum from under the back seat when you turn on the ignition, the pump or its relay is most likely to be faulty. If it hums but the engine is not running under load, it is often the fault of a clogged filter or pump grid.
Can I start Logan if I'm running the battery?
It is impossible to start a car with a fully dead battery (less than 8 volts) without external assistance, since the electronics will not turn on. It requires a light from another machine or the use of a booster.