Diagnosing and eliminating code P0021 on a Nissan Murano

DTC problem P0021 by car Nissan Murano is one of the most common complaints from owners, especially when using VQ35DE or VQ35HR series engines. This diagnostic code indicates that the engine management system has detected a discrepancy between the actual and the requested valve timing advance on the bank 2 intake manifold. In other words, the AVCS cannot set the desired position, or the camshaft position sensor is transmitting incorrect data, which leads to engine malfunctions.

Ignoring the alarm P0021 can lead to serious consequences for the power unit, including loss of power, unstable idling and even physical damage to the variable phase mechanism. Owners Nissan Murano They often encounter this problem after reaching 100,000 kilometers, when the elements of the VVT system begin to wear out or become contaminated with combustion products.

The essence of the error and the operation of the VVT system on Murano

Variable valve timing (VVT) systems in engines Nissan operates under the control of an electronic control unit (ECU), which analyzes data from the crankshaft and camshaft position sensors. When the computer detects that the intake camshaft on the second bank of cylinders does not reach a specified angle of rotation within a certain time, it issues a code P0021 — «A» Camshaft Position Timing Over-Advanced or System Performance (Bank 2).

The key element here is the solenoid (solenoid valve), which regulates the flow of oil to the phase regulator. If the oil does not flow or the oil pressure is insufficient, the mechanism cannot move the camshaft and the ECU sees a desynchronization. It is important to understand that the error can be caused by either an electrical fault or a mechanical blockage.

Second bank of cylinders in V6 engines Nissan usually located on the driver's side (in left-hand drive versions), which often makes accessing the VVT system components difficult. Error P0021 is often accompanied by a P0022 if the angle is lagging, or a P0020 if the control circuit is open, but it is P0021 that signals the actual physical lag or advance.

It must be taken into account that modern engines Nissan Murano very sensitive to the quality of engine oil. Thick or old oil simply will not be able to ensure rapid operation of the solenoid, which will lead to a false error code being recorded even with serviceable parts.

The main reasons for the appearance of code P0021

The list of potential culprits of the problem is quite wide, but repair statistics Nissan Murano allows you to highlight the most likely scenarios. Most often, the problem lies in the electrical part or contamination of the oil channels, and not in the breakdown of the camshaft itself.

• 🔧 VVT solenoid (AVCS) is dirty or stuck due to sludge and deposits in the oil.
• 🔧 Wear or stretching of the timing chain, which changes the basic valve timing.
• 🔧 Low engine oil level or use of inappropriate viscosity.
• 🔧 Damage to the wiring or oxidation of the contacts on the camshaft position sensor connector.

It is also worth paying attention to the phase regulator itself (camshaft gear). Over time, the spring inside the mechanism may lose its elasticity, or the locking pin may wear out, preventing the angle from locking in the correct position. In rare cases, the problem may be in the Engine ECU, although this happens extremely rarely.

If you have recently changed the oil filter or performed maintenance, check to see if the filter is of poor quality. Some cheap analogues do not maintain pressure in the system when starting, which causes an instant phase failure and an error record P0021 immediately after the engine starts.

Symptoms of a driving malfunction

When the system detects an error, it goes into emergency mode in an attempt to protect the engine. You may notice that the car Nissan Murano begins to behave inappropriately, especially when trying to accelerate sharply. Power drops as the ECU forcibly disables active timing, locking the camshaft in the middle position.

One of the most noticeable features is unstable idle speed. The tachometer needle may float, and the engine may vibrate more than usual. In some cases Nissan may stall when stopping at a traffic light, which creates a dangerous situation in city traffic.

The Check Engine light coming on is the first signal, but not the only one. If the error persists for a long time, you may experience increased fuel consumption and worse acceleration dynamics. The engine runs less efficiently because the mixture is not completely burned due to improper timing of the intake valves.

Sometimes, if there are serious problems with the timing chain, you can hear a metallic knock or ringing from the engine, especially when it is cold. This is a sign that the problem has moved from electrical to mechanical and requires immediate attention.

Diagnostics and testing of components

Before changing expensive components, it is necessary to conduct a thorough diagnosis. Start by checking the level and condition of your engine oil. If the oil is black, thick or has a burning smell, the problem can be solved by simply changing the oil and filter, as well as flushing the engine.

The next step is to check the electrical circuit. You will need a multimeter to measure the resistance at the VVT ​​solenoid. The normal resistance value is usually in the range from 7 to 14 ohms (the exact value depends on the model year). If the resistance is infinite or zero, the solenoid needs to be replaced.

Check the connectors for oxidation or moisture. The contacts must be clean and tight. If the wiring appears intact, try manually testing the solenoid by applying 12 volts to it (with correct polarity). You should hear a clear click from the valve.

• 📉 Use the OBDII scanner to view real-time data (Live Data) on the phase advance angle.
• 📉 Inspect the oil passages in the cylinder head for sludge blockages.
• 📉 Check the integrity of the timing chain by measuring its stretch with a specialized tool.

It is important to note that if the solenoid is working properly, but the error does not disappear, the problem may be in the phase regulator mechanism itself. In this case, you will need to remove the valve cover and visually inspect the gear for play and damage to the teeth.

Why does the error only appear when it's hot?

Often the problem lies in the viscosity of the oil. When cold, the oil is thick and puts pressure on the solenoid, but when it heats up it becomes liquid and the pressure drops, which is why the phase regulator does not hold the angle, and the system displays error P0021.

⚠️ Attention: Do not try to ignore the P0021 code if you hear a metallic knocking sound in the engine. This may indicate that the timing chain has jumped a tooth, which will lead to valves meeting the pistons and a major overhaul of the engine.

Step-by-step instructions for troubleshooting

If diagnostics show a faulty solenoid, replacing it is the simplest and most inexpensive solution. The procedure requires removing the air intake and possibly the valve cover to access the solenoid connector and mounting.

Before installing a new solenoid, be sure to clean the seat and oil passages of deposits. Use a special carburetor cleaner or carb cleaner, but avoid getting harsh chemicals on the rubber seals.

Install the new solenoid, observing the tightening torque of the bolts (usually about 5-7 Nm). Plug in the electrical connector and make sure it snaps all the way into place. After this, clear the error codes with a scanner and start the engine.

If replacing the solenoid does not help, the next step is to check and possibly replace the VVT sprocket. This is a more labor-intensive procedure that requires removal of the camshaft pulley. Please note that on VQ35DE engines the timing cover gasket will often need to be replaced when the timing control is removed to avoid future oil leaks.

• 🔩 Use a torque wrench to tighten all bolts according to factory specifications.
• 🔩 Check the condition of the camshaft oil seal, as it may be damaged when removing the gear.
• 🔩 After assembly, be sure to perform the learning procedure (learning mode) through the diagnostic scanner.

Impact of service quality and prevention

Many owners Nissan Murano they neglect the oil change regulations, considering an interval of 15,000 km to be sufficient. However, for engines with a VVT system, this interval is critical. The sludge formed in the oil clogs small channels in solenoids and phase regulators, making them inoperable.

It is recommended to change the oil every 7,000 - 8,000 km, especially if you operate the car in city mode with frequent traffic jams. Use only oils recommended by the manufacturer (usually 5W-30 or 5W-40 with API SN/SP approval) and original filters.

It is also important to monitor the oil level. In VQ35 engines, natural oil loss is possible at high mileage. A drop in level below the minimum results in a decrease in pressure in the VVT system, which is guaranteed to cause an error P0021 or P0022.

If you are planning a long trip, check the operation of the VVT system first. Start the engine, warm it up to operating temperature and scan for errors. The absence of codes and smooth readings of the phase advance angle on the scanner are a guarantee that the motor can cope with the load.

Component	Symptom of malfunction	Recommended Action
VVT solenoid	No click when 12V is supplied, resistance is outside normal	Replacing the solenoid and cleaning the channels
Oil	Thick, black, low level	Changing the oil and filter, washing
Timing chain	Metallic knock, stretching more than 3mm	Replacing the chain and tensioner kit
Phase regulator	Gear play, lock pin wear	Replacing the camshaft gear
Wiring	Open circuit, contact oxidation	Wiring harness repair or replacement

Cost of repairs and selection of spare parts

Costs to fix a bug P0021 may vary widely depending on the chosen repair method. The cheapest option is to replace the solenoid, which is relatively inexpensive if you do the work yourself.

When choosing spare parts for Nissan Murano It is strongly recommended to give preference to original parts (Nissan Genuine Parts). Analogues from unknown manufacturers often have lower workmanship, which leads to repeated failure of the solenoid or phase regulator after just a few thousand kilometers.

If the problem requires replacing the timing chain, the cost of repair increases significantly. In this case, not only the chain is often replaced, but also the tensioners, dampers and sprockets. Replacing a chain on a V6 engine takes a lot of time and requires a highly qualified technician.

If the error is caused by a software failure of the ECU, flashing the software may be required. This is done at an official dealer or in specialized services that have access to factory update databases for Nissan.

⚠️ Attention: Saving on oil and filters when repairing a V6 VQ35 engine often leads to the fact that six months later a new error P0021 appears, and you again spend money on repairs that could have been avoided.

Owner Frequently Asked Questions (FAQ)

Is it possible to drive with error code P0021 on a Nissan Murano?

Technically, the car will drive, but in emergency mode. Dynamics is significantly reduced, fuel consumption increases. You may not need to drive for long to get to the service center, but constant use can lead to wear on the timing chain and other serious damage.

Will cleaning the solenoid of dirt help?

Yes, if the problem is caused only by contamination. The solenoid can be disassembled, the filter mesh and rod can be cleaned of sludge in a solvent. However, if the solenoid is already mechanically worn out or its coil is damaged, cleaning will not help and the part must be replaced.

How much does it cost to replace a VVT solenoid?

The price of the original solenoid varies depending on the year of manufacture and region, usually from 4,000 to 8,000 rubles. Replacement work takes about 1-2 hours, if access is not obstructed by other nodes.

Why does P0021 appear after an oil change?

This could mean that the new oil has a different viscosity, or that the old oil had too much sludge that washed out and clogged the passages. It is also possible that a low quality oil filter does not hold pressure when starting.

Do I need to do training after replacing the solenoid?

Yes, after replacing or resetting errors, it is necessary to carry out a training procedure for the VVT system through a diagnostic scanner so that the ECU remembers the new operating parameters of the phase change mechanism.