P0418 - OBD Trouble Code

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An increase in the fuel consumption and the engine performance along with occasional engine stalling and with improper throttle response and acceleration may be an indication of problem with the air injection system hampering the engine’s performance, thus indicating OBD Code P0418.

OBD code P0418 is defined as “Secondary air injection pump relay A -circuit malfunction”, and is set when the PCM (Powertrain Control Module) detects a failure or malfunction in the SAI (Secondary Air Injection) circuit that is associated with the relay “A”. It is also important to note that some applications use more than one relay in the SAI system, and that this code refers specifically to relay “A” and its associated circuit.

In most modern applications a dedicated air pump is used to slightly compress ambient air, before blowing it into the exhaust manifold to help in oxidizing harmful exhaust emissions. Typically, SAI systems consist of an air pump that can be either belt driven or electrically operated, pressure sensors, various hoses, one-way check valves, switching valves, relays, fuses, bypass valves, and anti-backfire valves that are all controlled by the PCM.

What causes this problem with the Secondary Air Injection System Relay "A" Circuit Malfunction?

• Defective relay
• Damaged, shorted, disconnected, or corroded wiring and/or connectors
• Defective AIS pump/motor
• Blown fuses and/or fusible links
• Failed or failing PCM

1. Air Injection Pump - A damaged injection pump can be a primary reason for OBD code P0418 error. Buy new air pump now!
2. Air Control Valve Relay - Relay “A” malfunction is an important issue to be examined for and will require immediate replacement. Buy new valve relay now!
3. Air Injection Check Valve - Always check for injection valve damages and replace them if found faulty. Shop now!
4. Diagnostic Tools - You will require quality diagnostic tools to resolve this OBD issue. Buy factory grade tools from us!
5. Exhaust Manifold - P0418 can also be due to problems in the exhaust manifold. Replace it now!
6. Powertrain Control Module - Faulty PCM can interpret the information wrongly and cause wrong errors to get stored in the system. Repair or reprogram as required.

Next important thing you need to know about are the common symptoms for this obd error code P0418 with your fuel volume control.

Common Symptoms

• Stored trouble code and possibly an illuminated warning light
• Vehicle may not pass an emissions test if code P0418 is present
• In many cases, there may be no discernible symptoms other than a stored code, since SAI system activation (or otherwise) is not essential for efficient engine operation
• Engine hesitation and stalling
• Reduced performance

Wish to correct this error code with your vehicle? Do you know what all you should do to make your car free from this code? Well, don’t worry! We are here to guide you.

• One-way check valves replacement
• Damaged or faulty wiring or connectors replacement
• Damaged or cracked fittings or hoses replacement
• Blown fuses associated with the secondary air injection system replacement
• Secondary air injection pump replacement

If you need any parts to fix this problem you can easily find them with us. Not only that we also have in stock the best in range auto parts and that too at the most budget friendly prices ever online. Whether you need a Air Injection System, Check Engine Light, Injection Valve System, Engine Exhaust, Power Control Module, you can simply rely on us for quality auto parts.

It is essential to diagnose this fault code. Here are some steps which a mechanic should follow for diagnosing the problem that triggered a P0418 code to be stored:

• Check for any set of DTCs, and capture the freeze frame data, including the order in which the codes occurred.
• Clear all codes and test driving the vehicle to see if they return (if they don’t, this could indicate an intermittent condition, which is trickier to diagnose).
• Visually inspect all system wiring and connectors for damage or shorts.
• Inspect secondary air injection system fittings and hoses for cracks, breaks, or heat damage.
• Test system fuses, replace, and run the secondary air injection system to see if the fuses blow again (indicating possible pump failure).Inspect the one-way check valve to see if it’s allowing condensation to enter the pump.
• If everything checks out to be functioning properly, inspect for faults in the PCM and see if it requires reprogramming or replacement as it might be storing wrong errors.

Common Mistakes When Diagnosing the P0418 Code

Most of the time, the mechanics fail to drain excess water from the pump housing when replacing a damaged secondary air injection pump which can lead to the pump refreezing upon exposure to cold temperatures and the pump binding up and failing again. It is important to inspect and replace a faulty one-way check valve, which allows moisture to build-up and the pump to fail again upon water allowed into the system freezing.