What does the P0027 fault code mean?
The P0027 fault code, applicable to all car manufacturers, means “Exhaust Valve Control Solenoid Circuit Range/Performance (Bank 1)“.
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 B (exhaust) camshaft differs from the ideal position by more than 20 degrees.
Symptoms of P0027 Error Code
- Unstable engine idle
- Power loss
- Increased fuel consumption
- Check engine light illuminated
- Engine may stall
- Noticeable shaking during acceleration
Main Causes of P0027 Error Code
- Exhaust valve control solenoid (VVT) malfunction
- Contaminated or insufficient engine oil
- Camshaft position sensor (CMP) malfunction
- Damaged wiring or connectors
- Engine control module (ECM) malfunction
P0027 Error Code in Different Vehicles
P0027 in Honda Accord: In Honda models, especially those with VTEC engines, the P0027 error is often due to contaminated oil passages or worn VVT solenoids. Regular oil changes can help prevent this problem.
P0027 in Subaru Outback: In Subaru models with boxer engines, this error may indicate that the valves are difficult to move due to contamination. This is especially noticeable when using low-quality engine oil.
P0027 in Mazda 6: The Mazda P0027 fault code often occurs due to a camshaft position sensor malfunction. Wiring issues may also be a possibility.
P0027 in Ford Focus: In the Ford Focus, a common cause of this error is a faulty phase control solenoid. Program deviations may also be possible.
P0027 in BMW 3 Series: In BMW models equipped with VANOS, the error is usually due to internal system contamination or a camshaft position sensor malfunction.
How to Diagnose P0027 Error Code?
Step 1: Connect an OBD2 diagnostic scanner to confirm the presence of the P0027 error.
Step 2: Check the engine oil level and condition. Change the oil and filter if necessary.
Step 3: Visually inspect the wiring and connectors of the VVT solenoid and camshaft position sensor.
Step 4: Check the resistance of the exhaust valve control solenoid. Compare it to factory tolerances.
Step 5: If necessary, test the system using an oscilloscope or multimeter.
| Possible Causes | How to Check？ |
|---|---|
| Defective VVT solenoid valve | Measure resistance, perform power test |
| Oil sump contamination | Check the condition of the engine oil and filter |
| Camshaft position sensor malfunction | Perform diagnosis with an OBD scanner, check the signal with an oscilloscope |
| Damaged or poor contact of wires | Visual inspection, multimeter check |
| ECM software malfunction or failure | Scan, flash, or replace the control unit |
Tools needed: OBD2 scanner, multimeter, oscilloscope (if possible), a set of wrenches and screwdrivers, new oil filter and engine oil (if replacement is needed)
How to fix P0027 error code? (Solutions to the problem)
Simple fixes
- Reset the error after it has been triggered (if it only occurred once)
- Engine oil and filter replacement
- Clean the VVT solenoid valve
- Check and secure connectors and cables
In-depth diagnostic and repair solutions
- Replace the faulty valve timing control solenoid valve
- Check and replace the camshaft position sensor
- Flush the oil passages in the cylinder head
- Replace or flash the engine control module (if necessary)
| Symptoms | Possible solutions |
|---|---|
| Increased fuel consumption | Check and replace the VVT solenoid valve |
| Engine shaking at idle | Diagnosis and cleaning of oil passages |
| Check engine light on | Perform diagnosis with a scanner to eliminate the root cause |
P0027 Error FAQ
Can you drive with a P0027 error code?
It is not recommended, as a malfunction in the VVT system can lead to reduced engine performance and increased wear on components.
Can the P0027 error occur due to poor oil quality?
Yes, using low-quality or old engine oil can lead to contamination of the VVT solenoid valve and oil passages, triggering the error.
How can I reset the P0027 error myself?
You can use an OBD2 scanner, or temporarily disconnect the battery. However, if the cause is not addressed, the error is likely to reappear.
Do I need to replace the VVT solenoid valve immediately when I encounter a P0027 error?
Not necessarily. First, you should diagnose – the problem may be related to contamination or wiring, not the solenoid itself.
Which cars are more likely to encounter the P0027 error?
This type of error is more common in vehicles equipped with VVT systems, including Honda, Subaru, Mazda, Ford, and BMW.
Related OBD2 Errors:
P0011 – A Camshaft Position – Timing Over-Advanced or System Performance (Bank 1)
P0026 – Intake Valve Control Solenoid Circuit Range/Performance (Bank 1)
P0028 – Intake Valve Control Solenoid Circuit Range/Performance (Bank 2)
Important! Error P0027 may not cause serious problems initially, but if ignored for a long time, it can lead to VVT system failure, which can then affect the entire engine’s operation. Regularly changing the engine oil and filter, and using high-quality engine oil, are the best ways to prevent VVT system-related errors.