Introduction to Ignition System Diagnostics
Novice car enthusiasts often encounter the problem of sudden engine stops at Nissan Almera Classicwhen the car just stalls and won't start. In most cases, the root of all evil lies in the failure of a critical element of the engine control system - crankshaft position sensor (DPKV). Without the correct operation of this unit, the electronic control unit cannot determine the moment of fuel injection and spark formation.
Many owners Nissan Almera With a QG15DE engine, they spend time and money diagnosing spark plugs or coils, not realizing that the problem is located at the very bottom of the engine compartment. Crankshaft sensor is the only element without which starting the engine is impossible in principle, since it sets the synchronization of all processes. Understanding its exact location and design features will save you hours of searching.
Exact location of the sensor on the engine
If you open the hood of your car, you will immediately find the sensor at the bottom of the engine, closer to the gearbox. On Nissan Almera Classic with a 1.5 liter engine it is mounted directly on the clutch housing. You need to look at the joint between the cylinder block and the transmission where the crankshaft pulley is located.
Crankshaft position sensor installed so that its sensing element is directed towards the flywheel ring gear or pulley. It is accessed from below the car, although sometimes it is possible to get to it from above if you unscrew the protection and free up space. The sensor is attached with one bolt and is located in close proximity to the front wheel drives.
For a visual inspection, it is often necessary to lift the car onto a lift or pit. Please note that the sensor housing may be contaminated with oil or dirt, making locating difficult. Mounting bolt has a 10 or 8 mm wrench head (depending on the year of manufacture and modification). It is important not to confuse it with other sensors located nearby, for example, the camshaft position sensor.
⚠️ Attention: Before starting any work to find the sensor, be sure to disconnect the negative terminal of the battery to avoid short circuit in the wiring harness circuit.
- QG15DE (1.5 l)
- QG18DE (1.8 l)
- Other
- I don't know
Symptoms of malfunction and characteristic signs
How to understand what exactly crankshaft sensor failed, and not a problem with the fuel pump or immobilizer? The most obvious sign is the failure of the engine to start when the starter is running. The car can turn the starter normally, but there is no spark and no fuel is supplied to the cylinders.
Sometimes the malfunction is intermittent. The engine may stall while driving, especially in hot weather or when overheated. The icon will light up on the dashboard Check Engine, and when scanning via OBD-II adapter you will see error code P0335. This code indicates that there is no signal from the crankshaft position sensor circuit.
- 🚗 The car stalls while driving without warning
- 🔧 The engine does not start, the starter turns, but there is no spark
- ⚙️ Idle speed fluctuates before stopping
- 💡 The "Check Engine" light on the instrument panel comes on
It is important to note that if the sensor fails completely Nissan Almera Classic will no longer be able to drive until you replace the part. The electronic control unit goes into emergency mode, but without synchronization with the crankshaft it cannot work. Diagnostics with a multimeter will allow you to accurately confirm the hypothesis of a malfunction.
☑️ Checking the functionality of the sensor
Parameters and technical characteristics of the node
Sensor on Nissan Almera Classic is an inductive element with a magnetic core. Its operation is based on a change in the electromagnetic field as the pulley teeth pass past the sensitive element. For correct diagnostics, it is necessary to know the nominal resistance of the winding.
The standard resistance for a good sensor is in the range of 500 to 800 ohms, but the exact values may vary depending on the manufacturer of the part (OEM or equivalent). Insulation resistance should be infinite, that is, there should be no breakdown to the body. If the multimeter shows "0" or "∞" in the wrong places, the part is faulty.
The table below shows the main technical parameters that will help you when choosing a replacement or checking the current unit:
| Parameter | Meaning | Unit of measurement |
|---|---|---|
| Sensor type | Inductive | - |
| Winding resistance | 500–800 | Ohm (Ω) |
| Number of wires | 2 | pcs. |
| Fasteners | Bolt M6 | mm |
| Clearance to pulley | 0.5–1.5 | mm |
Step-by-step instructions for replacing the sensor
Replacement crankshaft sensor on Nissan Almera Classic does not require complex special equipment, but access to it may be limited. You will need a standard set of wrenches, a new sensor and possibly a socket extension.
First you need to remove the crankcase protection, if installed. Then, after raising the car, find the sensor in the area where the gearbox and engine meet. Disconnect the electrical connector by pressing the latch and unscrew the mounting bolt. Remove the old sensor and inspect it for mechanical damage.
Installation of a new element is carried out in the reverse order. Pay attention to the condition of the gasket (if provided by the design) or O-ring. Gap between sensor and pulley critical: too large a gap will lead to signal loss, too small - to mechanical damage.
- 🔧 Disconnect the negative terminal of the battery
- 🛠️ Remove the engine protection and unscrew the mounting bolt
- 🔌 Disconnect the connector by pressing the latch
- 🆕 Install the new sensor, maintaining the correct gap
What to do if the sensor cannot be unscrewed?
If the fastening bolt is stuck, do not try to yank it off. Use a penetrating lubricant (WD-40) and give it time to work. As a last resort, you can gently heat the bolt head, but avoid heating the sensor itself and the plastic parts.
⚠️ Attention: When installing a new sensor, do not over-tighten the mounting bolt to avoid stripping the threads in the motor housing, as the housing material may be aluminum.
Before installing the new sensor, clean the mounting area of dirt and oil using a rag and brake cleaner to ensure a tight fit.
Diagnostics of wiring harness and connector
Sometimes the problem lies not in the crankshaft position sensor, but in the wiring that goes to it. Vibration and high temperatures in the engine compartment lead to chafing of the insulation or oxidation of the contacts in the connector. Checking the chain is a mandatory step before purchasing a new part.
Inspect the wiring harness for damage. Often the wires become bent where they enter the connector. Use a multimeter to check the continuity from the sensor connector to the ECU connector. Wire resistance should be close to zero, and the insulation should not have breakdowns to ground.
If the contacts in the connector are oxidized, they can be cleaned with a special contact spray or carefully stripped. In some cases, replacing the entire connector helps, since the contacts inside it can “burn out.” Voltage check on the connector when the ignition is on, it will show whether power is supplied to the sensor.
Often the reason for sensor failure lies in an oxidized connector or damaged wiring harness, and not in the element itself.
Choosing an original or a high-quality analogue
When purchasing a replacement, it is important not to make a mistake with the part number. For Nissan Almera Classic the original sensor number often begins with the prefix 23731. However, the auto parts market offers many high-quality analogues from trusted brands that work no worse than the original.
Original Nissan sensors are more expensive, but guarantee perfect compatibility. Analog options from brands like Denso, NTK or Bosch also show excellent results and are often cheaper. The main thing is to avoid very cheap “no-name” products, as they can quickly fail due to unstable magnetic characteristics.
- ✅ Original: Nissan 23731-AX000 (or similar by year)
- ✅ Analogue: Denso, NTK, Magneti Marelli
- ❌ Avoid: Unknown Chinese brands without warranty
Results and recommendations for use
Knowing that where is the crankshaft sensor located on Nissan Almera Classic, allows you to quickly solve the problem with starting the engine. Regularly checking the condition of wiring and contacts can prevent sudden failures on the road. This is an inexpensive part, but its failure paralyzes the operation of the entire car.
If you replace the sensor and the car still won't start, check other systems: the fuel pump, fuses and ignition coils. However, in 90% of cases the problem is precisely in DPKV. Regular Maintenance and the use of high-quality spare parts is the key to the long life of your car.
Do not forget that after installing a new sensor, it may be necessary to reset the adaptations or simply several startup attempts to teach the ECU. The engine should run smoothly and the P0335 code will disappear after a few cycles of operation. System reliability depends on the quality of installation and serviceability of all components.
Where exactly to look for the crankshaft sensor on a Nissan Almera Classic?
The sensor is located at the bottom of the engine, at the junction of the cylinder block and gearbox. It is accessed from below the car through an inspection hole or a lift. It is attached to the clutch housing and is directed to the crankshaft timing pulley.
What error code indicates a bad crankshaft sensor?
The main error code that the OBD-II scanner records when the crankshaft position sensor is faulty is P0335. This code means "Crankshaft Position Sensor A Circuit".
Is it possible to start the engine without a crankshaft sensor?
No, it is impossible to start the engine without a working crankshaft sensor. The electronic control unit (ECU) does not receive information about the position of the pistons and cannot generate a spark or supply fuel.
How much does it cost to replace a crankshaft sensor at a service center?
The cost of the part itself varies from 1,500 to 4,000 rubles, depending on the brand. Service replacement work is usually inexpensive and takes about 30-60 minutes, since access to the sensor is relatively simple, although it does require lifting the car.