P0021 on Nissan Teana J31: decoding, causes and repairs

Nissan Teana J31 (2008–2013) with engines VQ25DE And VQ35DE - reliable cars, but even they are not immune to problems with the variable valve timing system VVT. One of the most common mistakes that owners encounter is P0021 ("Intake Valve Timing Control Performance Bank 2"). This code indicates a malfunction of the phase control valve intake camshaft on the second row of cylinders (from the passenger compartment).

The error cannot be ignored: it leads to loss of power, increased fuel consumption and the risk of serious engine damage. In this article, we'll look at what exactly is breaking, how to diagnose the problem yourself, and what steps to take to repair it - from simple cleaning to replacing components.

What does error P0021 mean on Nissan Teana J31

Code P0021 signals a discrepancy between the actual and expected position VVT intake valve on the second row of cylinders. System Variable Valve Timing (VVT) is responsible for optimizing valve timing depending on engine speed, providing better traction and efficiency. When the control unit (ECU) detects a delay or advance of valve actuation, it records an error.

On Teana J31 with motor VQ25DE/VQ35DE The VVT valve is controlled hydraulically through oil pressure. If the oil is dirty, the oil level is low, or the passages are clogged, the valve may not operate properly. The problem may also lie in the VVT ​​solenoid itself, the power circuit, or mechanical wear on the camshaft.

• 🔧 Mechanical part: camshaft gear wear, VVT valve jamming.
• ⚡ Electrical part: broken wiring, oxidation of solenoid contacts, malfunction of the camshaft position sensor (CMP).
• ⛽ Oil system: low oil pressure, clogged filter or passages, unsuitable oil viscosity.
• 💻 Software part: firmware failure ECU, incorrect data from sensors.

⚠️ Attention: If error P0021 accompanied by a knocking sound in the engine or a sharp drop in power, stop using the vehicle immediately! This may indicate critical damage to the camshaft or hydraulic lifters.

Reasons for error P0021

In practice 90% of cases errors P0021 on Nissan Teana J31 associated with oil system problems or mechanical wear of the VVT valve. Less commonly, electrical faults are to blame. Let's look at the main reasons in more detail:

1. Dirty or old oil. Over time, the oil loses its properties, and wear products clog the oil supply channels to the VVT valve. This is especially critical for engines with mileage >150 thousand km.
2. Faulty VVT solenoid. The valve (solenoid) may become stuck in the open/closed position or fail due to a broken winding.
3. Camshaft gear wear. On motors VQ VVT rotor splines or blades often wear out, blocking phase adjustment.
4. Low oil pressure. Causes: worn oil pump, clogged filter or pan, leaking seals.
5. Wiring problems. Oxidation of contacts on the solenoid connector or open circuit of the power supply.

The exact cause can only be diagnosed after testing. For example, if an error appears on a cold engine and disappears after warming up, the culprit is most likely oil (too thick in the cold). If the error is constant, there is a mechanical or electrical problem.

Diagnosing error P0021: step-by-step instructions

Before rushing to change parts, conduct a comprehensive diagnostic. Let's start with the simplest checks and gradually move on to complex ones.

1. Checking the oil and oil system

• 📋 Oil level: should be between the marks MIN And MAX on the dipstick. Low level is one of the main causes of error.
• 🔄 Condition of the oil: if the oil is black, with metal shavings or smells like burning, urgently replace it along with the filter.
• ⚙️ Oil pressure: check with a pressure gauge (standard for VQ25DE/VQ35DE - 2–4 bar at idle and 4–6 bar at rpm).

2. VVT solenoid check

The solenoid is located on the cylinder head on the intake manifold side (on the second row). To check it:

1. Remove the connector from the solenoid and check the resistance with a multimeter (normal: 6–10 ohms).
2. Submit to contacts 12V from the battery - a click should be heard (operating valve).
3. Inspect the filter screen inside the solenoid - if it is clogged, clean or replace the solenoid.

3. Checking the VVT camshaft and gear

To do this you will need to remove the valve cover. Please note:

• 🔗 Condition of the splines on the VVT gear - if they are worn out, the gear needs to be replaced.
• 🌀 The mobility of the rotor inside the gear - it should turn without jamming.
• 🛢️ Cleanliness of oil channels in the block head.

4. Error scanning and real-time data

Connect a diagnostic scanner (for example, Launch X431 or ELM327) and check:

• 📊 Options Intake VVT Bank 2 Advance - if the value deviates greatly from the norm (0–50°), the problem is mechanical.
• 🔌 Presence of additional errors (for example, P0011 — problem with exhaust VVT, P0340 - faulty camshaft sensor).

⚠️ Attention: If you see an error while scanning P0021 along with P0340 (camshaft position sensor), first check the sensor circuit and its connector. A faulty sensor may give false signals that the VVT is faulty.

How to fix error P0021: repair methods

The repair method depends on the cause of the problem. Below are step-by-step instructions for the most common cases.

1. Oil change and system flushing

If the oil is old or the channels are clogged, start with this:

1. Drain the old oil and replace the oil filter (we recommend original Nissan 15208-9F600 or Mann W712/92).
2. Fill in flushing oil (e.g. Liqui Moly Pro-Line) and let the engine idle for 10–15 minutes.
3. Drain the flush and fill with new oil with a viscosity 5W-30 or 5W-40 (for VQ fits Nissan Strong Save X 5W-30).

2. Clean or replace the VVT solenoid

If the solenoid is clogged or does not click when voltage is applied:

• 🧹 Remove the solenoid and wash it in carburetor cleaner (for example, Abro CC-220). Pay special attention to the filter mesh.
• 🔧 If cleaning does not help, replace the solenoid with a new one (original Nissan 23731-4M200 or equivalent Hitachi L165-18-500A).

3. Replacement of VVT gear or camshaft

If the splines or rotor of the VVT gear are worn, it must be replaced. To do this:

1. Remove the valve cover and timing belt (on VQ35DE timing chain, so you will need a special tool to fix the shafts).
2. Remove the old gear and install a new one (original Nissan 13028-4M200).
3. Check the condition of the timing chain and tensioners - if the mileage is high, they should also be replaced.

Detail	Original art.	Analogue	Approximate price, ₽
VVT Solenoid (Intake, Bank 2)	23731-4M200	Hitachi L165-18-500A	4 500–7 000
VVT gear	13028-4M200	Ajusa 130284M200	8 000–12 000
Oil filter	15208-9F600	Mann W712/92	400–800
Timing chain (set)	13028-4M210	INA 530053310	15 000–20 000

Prevention of error P0021 on Nissan Teana J31

To avoid the error reappearing P0021, follow these guidelines:

• 🛢️ Change the oil every 8–10 thousand km, even if the mileage is short. For VQ-It is critical for engines to use high-quality synthetic oil.
• 🔧 Flush the oil system at every oil change (for example, Liqui Moly Oil-Schlamm-Spulung).
• ⚡ Check the wiring VVT solenoids for oxidation every 50 thousand km.
• 📊 Scan for errors diagnostic scanner at every maintenance, even if there are no symptoms.

Pay special attention to the choice of oil. For Nissan Teana J31 with motors VQ25DE/VQ35DE oils with approval are optimal Nissan Strong Save X or analogues with viscosity 5W-30/5W-40 and specification API SN/ILSAC GF-5.

What happens if you ignore P0021?

Long driving with error P0021 leads to:

- Accelerated wear of camshafts and hydraulic compensators.

- Increased fuel consumption (up to +20%).

- Risk of timing chain break due to uneven load.

- Catalyst failure due to improper fuel combustion.

Frequently asked questions about error P0021 on Nissan Teana J31

Is it possible to drive with error code P0021?

Short term - yes, but not recommended. Long-term operation will lead to accelerated engine wear. If the error appears for the first time, check the oil and solenoid. If the error is permanent, repair is required.

How much does it cost to repair P0021?

The cost depends on the reason:

- Oil change + flushing: ~2,000–3,000 RUR.

- Cleaning/replacing the solenoid: 3,000–8,000 ₽.

- VVT gear replacement: RUB 15,000–25,000 (including labor).

- Camshaft repair: from 30,000 ₽.

Could P0021 be caused by bad gasoline?

No, error P0021 related to the VVT system and oil system, not fuel. However, low-quality gasoline can cause other errors (for example, P0300 — misfires).

Do I need to reset the error after repair?

Yes, but not right away. After eliminating the cause, start the engine, let it run for 5–10 minutes and only then reset the error with the scanner. If she doesn't come back, the problem is solved.

Can I replace the VVT solenoid myself?

Yes, this is a simple procedure:

1. Remove the intake manifold (on VQ35DE you will need to remove the throttle body).

2. Disconnect the connector and unscrew the solenoid with a key to 10 mm.

3. Install a new solenoid, connect the connector and check for oil leaks.