What is an OBD P2279 Fault Code and how to fix it
If your car is coming up with a P2279 code on your OBD-II reader, you've come to the right place as we'll explain everything you need to know about this car trouble code and how to sort it.
What does the P2279 fault code mean?
The P2279 error is an OBD-II generic code specifying that the engine control module (ECM) has detected a vacuum leak in the intake air system, allowing unmetered air to enter the engine. It indicates the air entering the intake manifold is greater than the Manifold Absolute Pressure (MAP) Sensor, meaning you have an intake air system leak.
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How serious is the P2279 fault code?
The P2279 diagnostic code is not considered serious. The ECM detects how much air is entering, notices that it's too much and sees this as an air leak. But it doesn't prevent the vehicle from being driven. However, whilst you can continue to drive a car registering this trouble code, an engine running in this condition will run lean, causing the engine to run rough and stall at low engine speeds. It's therefore advisable to book the vehicle in for diagnostic and repair as soon as possible.
What are the common symptoms of a P2279 trouble code?
When a P2279 OBD-II code is triggered, you can expect the following symptoms:
Check engine light illuminates
The engine may run rough with a loss of power
Engine may stall
The engine may run lean and misfire
Decreased fuel efficiency
What are the causes of a P2279 diagnostic code?
The most common causes for the P2279 trouble code are:
A disconnected vacuum hose or cracked hoses
The PCV (positive crankcase ventilation) valve or hose is damaged or leaking
Possible air leak between the mass air flow sensor (MAF Sensor) and the intake manifold
Leaking inlet air temperature (IAT) sensor
Has the throttle body recently been cleaned with the throttle relearn process
Damaged intake manifold
How to diagnose a P2279 OBD-II code?
Using an OBD-II scanner or booking a diagnostic check with a trusted mechanic or garage is the easiest way to diagnose and resolve an OBD-II fault code. Following the diagnostic steps fully and correctly is essential for accurate diagnosis:
Scan your system for other OBD-II codes. If present, these must be resolved first.
Clear the fault codes, and follow this with a test drive of the car while reading the live data on an OBD-II scanner.
If the code persists, listen to the engine for any vacuum leaks, including loose or broken vacuum hoses or air inlet hoses
Inspect the PCV valve to check it's not stuck in an open position
Check the throttle body to see if it's recently been cleaned and the throttle relearn process performed
How to fix a P2279 OBD-II trouble code?
It is recommended to test drive the vehicle after each check/work is performed to see if the fault code clears. If the code returns, move on to the next repair, as it may indicate a faulty component . The most common repairs to resolve a P2279 code are:
Verify the code with an OBD-II scanner, and reset the fault code. Follow this with a test drive of the car to see if the trouble code clears. If it returns:
Repair or replace any loose or broken vacuum hoses or air inlet hoses
Replace leaking intake gaskets or seals
Replace defective PCV valve
Replace faulty MAP sensor
Perform throttle relearn process for the ECM
How to avoid a P2279 code?
Whilst the P2279 diagnostic trouble code can be attributable to component failure, it's also possible that something as simple as loose or damaged hoses can be the cause. Undertaking simple checks and preventative measures will keep your car in optimum condition. Similarly, it's always beneficial to regularly maintain your vehicle's engine in good working order. Servicing your car frequently, including changing the oil along with the oil and air filters and generally visually checking for problems with wiring, connectors, hoses, and seals, will ensure your vehicle remains in good running order as much as is possible.
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