Localization and diagnostics of the crankshaft sensor on Nissan Primera P12

Introduction to the engine starting problem

Getting started on your Nissan Primera P12 may be suddenly interrupted due to a critical failure in the ignition system. If the engine turns with the starter, but does not catch, the problem often lies in the lack of a signal about the position of the pistons. Crankshaft position sensor (DPKV) is the only element without which the electronic control unit (ECU) cannot synchronize the fuel supply and spark.

Owners Primera P12 With engines of the QG or QR series, they often encounter this malfunction, which is disguised as problems with the fuel pump or spark plugs. Without the correct signal from this device, the injector simply will not open the injectors at the right time, which makes starting impossible, even if all other systems are working.

Exact location on various modifications

The location of the element directly depends on the type of engine installed, which often causes confusion among owners. On units QG18DE (1.8 liter) sensor is located at the bottom of the engine, on the gearbox side, closer to the clutch housing. This is the most problematic area due to dirt and oil penetration.

For engines QG20DE and QG25DE the situation is similar, but access may be slightly different due to the characteristics of the attachment. In rare cases on versions with engine QR25DE (2.5 liters) location may move closer to the flywheel, but the search principle remains the same: look for the element directed towards the gear disk.

Key Feature Nissan Primera P12 is that crankshaft sensor located in a hard-to-reach place, hidden by heat shields and suspension elements. You will either have to put the car on a lift or use an inspection pit to visually inspect the underside of the powertrain.

Symptoms of failure and diagnosis

The first sign of a malfunction is unstable engine operation at idle or a complete refusal to start. The electronics no longer understand where top dead center is and blocks fuel injection to protect the catalyst. Sometimes the car may stall while driving, especially when you suddenly release the gas or at a traffic light.

The indicator on the dashboard may come on Check Engine, however, when scanning, the error is not always read immediately, since the sensor may simply turn off when heated. If you see an error code P0335 or P0336, this is a direct indication of problems with the control circuit crankshaft position sensor.

Sometimes the problem lies not in the element itself, but in damage to the wiring harness. Engine vibration over time leads to chafing of the insulation or oxidation of the contacts in the connector. It is necessary to carefully inspect the wiring going to the installation site for mechanical damage.

Tools and preparation for replacement

To carry out the work, you do not need a specialized stand, but a basic set of tools is required. You will need 10 and 12 socket wrenches, a flathead screwdriver to remove the connector, and penetrating lubricant if the mounting bolt is stuck. Don't forget about the new one crankshaft sensor and an o-ring.

Be sure to make sure the engine is cool before starting work. When working in the engine compartment or under the car, you risk getting burns from hot parts of the exhaust system or cylinder block. Disconnect the negative terminal of the battery to avoid short circuit when disconnecting the connector.

Inspect the connection connector. Often the problem is solved simply by cleaning the contacts and applying dielectric grease, which eliminates oxidation. If everything is visually intact, proceed to removing the device itself to check the resistance with a multimeter.

Step-by-step instructions for removal and installation

First remove the engine guard and any plastic covers blocking access to the bottom of the engine. Locate where the sensor attaches to the cylinder block near the flywheel. It will be directed perpendicular to the axis of rotation of the crankshaft, its sensitive element faces the gear disk.

Carefully disconnect the electrical connector by pressing the latch. Unscrew the fastening bolt, which is usually about 70-80 mm long. Remove the old sensor, being careful not to damage its sensitive head. Pay attention to the condition of the magnetic tip - it should be clean, without metal shavings.

Clean the seat from dirt and sealant residues, if it was previously used. Install a new element with a new O-ring, tighten the bolt to the recommended torque, but do not overtighten so as not to strip the threads in the aluminum block. Connect the connector until you hear a characteristic click.