The P0021 OBD-2 code is a powertrain code in vehicles with either variable valve or camshaft timing systems. These technologies allow engines to function efficiently at different rates of speed. When the camshaft timing is over-advanced or beyond a preset limit, the P0021 code is engaged. This code is the Bank-2 version of P0011, which is for Bank-1.
In some vehicles, the engine oil moves through the camshafts. Some of these vehicles have small oil control valves. If you use the wrong oil viscosity, the oil valves can become clogged. This is a noticeable problem that will affect the drivability of the vehicle. The problem should be diagnosed and repaired quickly to avoid serious engine damage.
P0008 Code Definition
- P0021 Generic: Camshaft Position A – Timing Over-Advanced or System Performance (Bank 2)
- P0021 Nissan: Camshaft variable timing control – Bank 2 – performance
What Does P0021 Mean?
The OBD-2 code P0021 means that the camshaft has advanced beyond its predetermined position. The over-advancement of the camshaft happens when it is advancing or retarding. The code is sent to the Engine Control Module by the sensor near the bank-2 intake camshaft.
The ECM receives signals from the crankshaft, camshaft, engine, and temperature controls then send a message to the intake valve timing control solenoid valve. The message is based on the speed and temperature of the engine. After that, the timing of the intake valve changes to direct oil flow which controls the angle of the valve, either advancing or retarding it. A long flow advances the valve, whereas a short flow retards it. When the flows are equal, the oil pressure is stopped so the angle can be fixed. This is when the ECM ignites the P0021 code and check engine light.
In a Nissan, the P0021 code is sent to the ECM when the intake valve timing is off. When the hydraulically-controlled cam has a gap between where it should be and where it actually is. The wrong angle of the cam makes the intake valve stop working and sends the OBD-2 code. The code can also be sent when the engine oil is dirty or the wrong viscosity. This causes the intake valve solenoid valve to get stuck in the wrong position.
What Are The Symptoms Of The P0021 Code?
- Hard starting
- Difficulty idling
- Engine stalling
- Engine hesitation when accelerating
- Engine stalling when accelerating
- Emissions that overshoot federal standards
- Camshaft failure
- Solenoid failure
- Reduced fuel efficiency
What Are The Causes Of P0021?
There are several reasons why the P0021 code could be triggered. Some are related to the camshaft in Bank-2, but others are more complicated. The causes include:
- Solenoid failure
- Oil maintenance issues
- Using the wrong engine oil
- Blockage in the oil filter from incorrect engine oil
- Camshaft advances beyond the ECM’s command or without being told to retard
- Camshaft phaser sticks at an advanced angle
- Intake valve timing solenoid is faulty
- Intake valve timing solenoid is in the wrong position
- The camshaft position sensor is faulty
- The crankshaft position sensor is faulty
- Electrical connections are damaged or shorted
How Serious Is P0021 Code?
The OBD-2 code P0021 is relatively serious. When the engine stalls or hesitates, the passengers can be put in unsafe conditions. The vehicle might use more fuel than normal, which can create problems in the environment. Carbon fouling in the engine can also happen with excessive fuel use. The problem needs to be repaired to avoid more serious engine issues.
How To Diagnose And Fix Code P0021
- OBD-2 scanner
- A multimeter
- Hand tools
- Manufacturer’s vehicle manual
- Cleaning rags
- Use the OBD-2 scanner to double-check the code. Then, clear the code.
- Use a multimeter to check the terminals for solenoid failure. Check the multimeter for an ohm reading between 7-12 which is the ideal range. If it is off, then the solenoid most likely needs to be replaced.
- Run a pin test between the solenoid and the ECM.
- Before making repairs, check for damaged wires or connectors at the sensors. Then, look for sludgy oil and that the correct viscosity is being used.
- Scan with the OBD-2 scanner again to collect freeze-frame data to learn when the code was triggered. After collecting data, clear the code and retest the vehicle to see if code sets.
- Run through the manufacturer’s pinpoint tests.
- Use hand tools to tighten harness terminals at the solenoid. Use the rag when needed to clean the terminals. Lubricate the contacts with grease for ideal electric contact. Change the solenoids if necessary.
- Change the engine oil and filter using the manufacturer’s recommended viscosity.
- Using the hand tools, repair or replace wiring on the bank-2 camshaft control valve. If necessary, replace the camshaft in bank 2. Also, check the timing chain and repair or replace if needed.
Common Mistakes While Diagnosing The Code P0021
This code can be mistakenly determined if you do not take the correct diagnostic steps. To avoid a misdiagnosis, be sure to:
- Visually inspect electrical connections for damage
- Check the engine oil for the correct viscosity
- Reset and retest the OBD-2 code
- Run through the manufacturer’s pinpoint test exactly
Tips To Avoid P0021 In The Future
To avoid triggering the P0021 code, there are several steps to take. The first is the check your engine oil according to the manufacturer’s standards. Only use the oil viscosity recommended in the manufacturer’s vehicle manual. Another step you can take is to avoid driving on bumpy roads to keep the wiring intact. Also, follow the manufacturer’s recommendations for routine maintenance.
Read more: https://garatos.com/p0011-code/