What is the P0028 error code?
The P0028 fault code, applicable to all car manufacturers, means “Intake Valve Control Solenoid Circuit Range/Performance (Bank 2)“.
Background Information: The camshaft controls the opening and closing of the valves. In a variable valve timing system, the electronic camshaft adjusting valve (or oil control valve, OCV) adjusts the camshaft angle by changing the oil pressure to the camshaft adjuster (mechanical type) according to instructions from the engine control module (ECM), ensuring the valves open and close at optimal times. This fault code appears if the actual position of the intake camshaft (A) differs from the ideal position by more than 20 degrees.
Symptoms of P0028 Error Code
- Decreased acceleration
- Reduced engine power
- Unstable idle
- Increased fuel consumption
- “Check Engine” light illuminated
Main Causes of P0028 Error Code
- Contamination or malfunction of the Oil Control Valve (OCV)
- Low or dirty engine oil
- Mechanical failure of the VVT system
- Camshaft position sensor malfunction
- Open or short circuit in the OCV wiring
P0028 Error Code in Different Vehicles
P0028 in Subaru: This is often due to the VVT system’s sensitivity to oil quality. Regular oil changes are recommended.
P0028 in Ford: It may be caused by a faulty solenoid valve or oil contamination. In some cases, an ECU software update may help.
P0028 in Toyota: This is usually related to clogged oil passages or VVT actuator malfunction. Using genuine oil is recommended.
P0028 in Nissan: This may be the result of a faulty phase sensor. The valve may also be contaminated.
P0028 in Chevrolet: Sometimes the error is caused by a solenoid valve failure or internal damage to the phase actuator.
How to Diagnose P0028 Error Code?
Step 1: Read the error code using an OBD2 scanner.
Step 2: Check the engine oil level and condition. Change the oil and oil filter if necessary.
Step 3: Visually inspect the wiring and connectors of the Bank 2 solenoid valve.
Step 4: Check the resistance of the VVT valve. Compare it to factory specifications.
Step 5: Perform a load test on the VVT system using diagnostic equipment.
| Possible Causes | How to Check？ |
|---|---|
| Dirty VVT valve | Remove and visually inspect the valve, check for resistance |
| Contaminated or old engine oil | Check the oil level and condition, replace if necessary |
| VVT system mechanical principles | Check gears and couplings, check for blockages |
| Camshaft position sensor | Read values with a scanner, check wiring |
| Wiring fault | Check cables, connectors, and signal integrity |
Tools needed: OBD2 scanner, multimeter, oil pressure gauge, a set of wrenches and screwdrivers
How to fix P0028 error code? (Problem solutions)
Simple repair methods
- Engine oil and filter replacement
- Clean contaminants from the VVT valve
- Reset the error code and recheck
In-depth diagnostic and repair solutions
- Replace the defective VVT valve (OCV)
- Repair or replace damaged wiring
- Check and replace the valve timing sensor
- Check oil pressure and the health of the oil pump
- Remove and inspect the VVT coupling
Troubleshooting by symptoms
| Symptom | Possible solution |
|---|---|
| Decreased acceleration | Check VVT valve, oil pressure |
| Unstable idle | Clean or replace the valve, check the phase sensor |
| Increased fuel consumption | Check the correct operation of the VVT system |
| Check the engine | Count and reset errors, re-diagnose |
P0028 Error FAQ
Is it possible to continue driving with error P0028?
Prolonged use with the P0028 code activated may lead to reduced power and engine wear. It’s better to fix the problem as soon as possible.
Can low-quality engine oil cause the P0028 error?
Yes, dirty oil or oil with inappropriate viscosity often leads to VVT system malfunctions, causing this error.
Will the P0028 error reset after an oil change?
Sometimes yes – if the cause is simply oil contamination. However, in most cases, cleaning or replacing the VVT valve is also required, and the code needs to be manually reset with a scanner.
Do I need to replace the VVT valve when the P0028 fault code appears?
Not necessarily. Sometimes cleaning and flushing are enough. But if the valve is damaged or does not work properly after cleaning, it needs to be replaced.
Is it normal for the P0028 error to appear occasionally?
No, even occasional errors indicate an initial problem with the VVT system. It’s best to perform a complete diagnostic.
Related OBD2 errors:
P0011 – A Camshaft Position – Timing Over-Advanced or System Performance (Bank 1)
P0013 – B Camshaft Position – Actuator Circuit/Open (Bank 1)
P0026 – Intake Valve Control Solenoid Circuit Range/Performance (Bank 1)
Important! Some cars may not show obvious signs of malfunction in the early stages. However, with the persistent presence of code P0028, more serious engine problems may develop over time. Do not delay diagnosing and fixing the error. First, check the engine oil and the VVT valve – in most cases, this will solve the problem without compromising pressure.