The crankshaft position sensor (CPS) is one of the critical elements of the engine management system of any modern car, including the popular one in our latitudes Nissan Bluebird Sylphy. It is this component that is responsible for synchronizing the operation of the fuel injectors and the ignition system, transmitting data about the rotation speed and shaft position to the electronic control unit (ECU). If this element fails, the engine stops starting or runs with serious interruptions, which creates significant inconvenience for the owner.
Many car owners are faced with the problem of finding a place to install this sensor, especially if they do not have in-depth knowledge of the structure of the power unit. Depending on the year of manufacture and modification of the engine (whether it is a naturally aspirated 1.6 l or a more powerful 2.0 l), the location may have slight differences, but the general principle remains the same. Understanding exactly where it is crankshaft sensor, will allow you to quickly diagnose and, if necessary, replace the part without contacting specialized services.
Sensor location on HR and QG series engines
On most models Nissan Bluebird Sylphy, equipped with HR series engines (for example, HR15DE or HR20DE), the sensor is installed in the lower part of the engine, in the area of the flywheel or crankshaft damper. It is attached to the gearbox housing or cylinder block so that its sensing element is located opposite the flywheel ring gear or crankshaft pulley. This allows it to read gaps between teeth, generating a signal about the position of the shaft.
If you consider a specific installation area, then you need to find the junction of the engine and transmission. The sensor is usually screwed into the housing from the top or side, depending on how it is more convenient to approach it, taking into account the engine compartment. On QG series engines that were installed on earlier modifications, the location is similar, but the sensor housing itself may have a different shape and connector configuration.
It is important to note that access to the element is often limited by other components: the generator, drive belts or suspension components. In some cases, a full inspection may require removing the plastic engine guard or even removing the right wheel and fender liner to gain direct access to the bottom of the engine compartment.
Symptoms of malfunction and diagnostic errors
Understanding the signs of a breakdown will help you avoid wasting time looking for other problems if the problem is with the sensor. The most obvious symptom is the inability to start the engine: the starter turns, but the engine does not catch. This happens because the ECU does not receive information about the position of the shaft and, therefore, does not supply a spark and does not open the injectors at the right time.
In addition, you may observe sudden dips in engine performance at idle or under load. The car may suddenly stall while driving and then start again after a few seconds. At the same time, the indicator on the dashboard often lights up Check Engineindicating an error in the engine management system.
When you connect a diagnostic scanner, you may see error codes related to the sensor circuit or lack of signal. The most common codes are P0335 (crankshaft position sensor circuit malfunction) or P0336 (sensor signal abnormal). These codes clearly indicate that the problem is localized to this particular node.
Sometimes the problem is not in the sensor itself, but in the wiring or connector. Oxidation of contacts, frayed insulation, or damage to the wiring harness due to vibration can cause an intermittent signal. Therefore, when diagnosing, attention should be paid not only to the body of the part, but also to the cable path from the sensor to the computer.
⚠️ Warning: Do not try to start the engine multiple times in a row if it does not start. This can cause the battery to discharge and flood the cylinders with gasoline, making the situation worse.
- 1.6 l (HR15DE)
- 2.0 l (HR20DE)
- 1.8 l (QG18DE)
- Other
Tools for removal and replacement
Before starting work, you need to prepare the necessary set of tools. To remove the crankshaft sensor on Nissan Bluebird Sylphy you will need standard wrenches and sockets, as fastening is usually done with a single bolt or nut. You also cannot do without a Phillips screwdriver to unfasten the connector latches.
It is recommended to have a set of sockets with a ratchet, an extension and a universal joint on hand, since the sensor installation location is often in a hard-to-reach area. If the sensor is stuck or over-tightened, a penetrating lubricant may be required to pre-treat the threads.
Do not forget to prepare a clean rag and a container to collect possible leaks of technical fluids, since when dismantling the sensor, a small amount of oil may leak out if it is installed in the oil sump area. A multimeter is also useful to check the continuity of the circuit and the winding resistance of the new part.
☑️ Preparing to replace the sensor
Step-by-step replacement instructions
The first step is always to de-energize the vehicle. Open the hood and disconnect the negative terminal from the battery to prevent a short circuit when disconnecting the electrical connectors. This is a standard safety precaution for all electrical and electronic work.
Next you need to find the sensor itself. Depending on access, you may have to remove the crankcase guard or remove the wheel. Find the sensor connection connector, press the latch and carefully disconnect the plug. Be careful not to break the plastic latches, which become brittle over time.
Unscrew the mounting bolt holding the sensor. Remove the part from the seat. Pay attention to the condition of the O-ring - if it is damaged or has lost its elasticity, it must be replaced to prevent dirt and oil from getting inside the housing.
Install the new sensor, carefully screw in the mounting bolt and tighten it with moderate force. Do not overtighten the bolt, as the sensor body may be made of plastic or brittle metal, which will lead to its destruction. Connect the electrical connector until you hear a characteristic click.
What to do if the sensor cannot be removed?
If the sensor is stuck, do not use excessive force to avoid breaking its housing. Use a penetrating lubricant and give it time to work. You can gently tap the sensor body through the wooden spacer to loosen the fit, but be careful not to hit the sensing element.
Performance check and calibration
After installing a new element, you need to check its functionality. Connect the battery and try to start the engine. Normally, the engine should start the first time, and the Check Engine light should go out after several starting cycles. If the error remains, there may be a problem in the wiring or the control unit itself.
For more accurate diagnostics, you can use a multimeter. Measure the resistance of the sensor winding, comparing the data obtained with the nominal values specified in the technical documentation. Typically, resistance ranges from 500 to 1500 ohms, but the exact numbers depend on the specific sensor model.
If the error does not disappear after replacing the sensor, try cleaning the connector contacts with a special cleaner or wiping them with alcohol. Sometimes it is enough just to restore contact for the system to start working correctly. It is also worth checking the gap between the sensor and the ring gear, although on most models it is automatically adjusted upon installation.
It is important to ensure that the wiring is not damaged and is not in contact with hot engine components or moving parts. Correct routing of the harness will prevent the problem from reoccurring in the future.
Before final assembly, check that the wire from the sensor does not touch the hot exhaust manifold. High temperatures can melt the insulation and cause a short circuit.
Features and Compatibility Table
When choosing a replacement, it is important to focus on the correct characteristics of the part. Below is a table with the main parameters that will help you choose the right sensor for your Nissan Bluebird Sylphy.
| Parameter | Meaning | Note |
|---|---|---|
| Sensor type | Inductive | Works on the principle of electromagnetic induction |
| Winding resistance | 800–1200 Ohm | Depends on manufacturer and temperature |
| Fasteners | 1 M6 bolt | Tightening weight: 8–10 Nm |
| Location | Lower part of the gearbox | In the area of the crankshaft flywheel |
| Original number | 23731-8H400 | Check the relevance of the VIN number |
Please note that the table shows average values. For your specific machine, it is best to check the part number against the information in the catalog or on the body of the old part. The use of non-original analogues may lead to unstable operation of the engine, since the magnetic field parameters may differ.
Selecting the correct sensor with the original number and checking the resistance before installation is the key to long and stable operation of the ignition system.
Common mistakes when replacing
One of the most common mistakes is installing the sensor without replacing the O-ring. Over time, the rubber hardens and loses its tightness, which leads to oil getting inside the sensor housing. This can cause corrosion of the contacts and failure of the element in the shortest possible time.
Another mistake is damage to the sensitive part of the sensor during installation. If you accidentally hit it with a tool or drop it, its performance may be impaired. Always handle the sensor carefully and do not hit the end of the sensor.
Sometimes drivers forget to disconnect the battery before starting work. This may result in sparking when the connector is disconnected, which can damage the contacts or even cause the electronic control unit to malfunction. Follow safety regulations.
⚠️ Attention: Do not use lubricant on the sensor threads unless specified in the manufacturer's instructions. Excess lubricant can get on the sensing element and distort the signal.
It is also worth checking the integrity of the wiring harness. If you see signs of chafing or melting, replace the wiring or use heat shrink tubing for insulation. Neglecting this step will lead to the fact that even a new sensor will not work correctly.
Conclusion and recommendations
Replacing the crankshaft sensor with Nissan Bluebird Sylphy - a task that any car owner with minimal repair skills can handle. The main thing is to accurately determine the installation location, prepare the necessary tools and follow the instructions. This will save money on service costs and quickly return the car to normal operation.
Remember that regular diagnostics of your vehicle's electrical system can help prevent many serious breakdowns. If you notice unstable engine operation or errors appearing on the dashboard, do not put off visiting a specialist or checking it yourself.
High-quality spare parts and careful installation are the key to the long service life of your car. Don't skimp on sensors and choose trusted brands to avoid repeated visits to the garage. The exact location of the crankshaft sensor on the Nissan Bluebird Sylphy is at the bottom of the engine, at the junction with the gearbox, next to the flywheel.
⚠️ Attention: If after replacing the sensor the engine continues to operate unstably, contact a professional for an in-depth diagnosis of the engine control system.
Where exactly is the crankshaft sensor located on the Nissan Bluebird Sylphy?
The sensor is located at the bottom of the engine, near the junction of the cylinder block and the gearbox. It is attached to the gearbox housing or cylinder block and looks at the flywheel ring gear.
What symptoms indicate a bad crankshaft sensor?
Main symptoms: inability to start the engine, frequent stalling, drops in speed, the Check Engine indicator lights up and error codes P0335 or P0336.
Do I need to reset errors after replacing the sensor?
Usually the error resets automatically after several engine starting cycles. If the light does not go off, you can use a diagnostic scanner to force the error codes to clear.
Is it possible to drive with a faulty crankshaft sensor?
No, the engine will not start or operate correctly. Driving with a faulty sensor is impossible, since the ECU will not be able to synchronize the operation of the ignition and fuel injection systems.
What tool is needed to replace the sensor?
You will need 10 and 12mm wrenches or sockets, a Phillips screwdriver for the socket, a ratchet with an extension, and possibly some penetrating lubricant to loosen a stuck bolt.