Technical Description of OBD-II Trouble Code
Range/Performance Issue with Air Assisted Injector Control
What does that signify?
This diagnostic trouble code (DTC) is a generic powertrain code that applies to OBD-II equipped vehicles with an air assisted fuel injector. It can be found in various vehicle brands such as Subaru, Jaguar, Chevy, Dodge, VW, Toyota, Honda, etc., but it is more commonly seen in Subaru and Jaguar vehicles. While the code is generic, the specific repair steps may vary depending on the make, model, and engine.
The Air Assisted injector functions similarly to a normal fuel injector. As the name suggests, it uses air to help atomize the fuel during injection. In most cases, this injector is used to aid in cold starts. When the engine is cold, it requires a richer air/fuel mixture (more fuel) to start.
The atomization that occurs when air is introduced to a normal injector is desired because it helps achieve a more evenly distributed spray. This is important because these systems typically use only one injector mounted to the throttle body or intake, and the atomized fuel spray is distributed among multiple cylinders.
The ECM (engine control module) triggers the check engine light with the P0065 code and related codes when it detects a condition outside the specified range within the Air Assisted Injector’s circuit. Generally, this is an electrical issue, but sometimes an internal malfunction within the injector itself can cause this condition.
The P0065 Air Assisted Injector Control Range/Performance code is set when the ECM detects an out of range condition within the injector. This air assisted injector control DTC is closely related to P0066 and P0067.
What is the severity of this DTC?
The severity of this code can be considered moderate to low. It will not significantly affect the overall performance of the engine at normal operating temperature. However, it should be addressed eventually because consistent cold starts with a potentially lean mixture could cause serious damage in the long run.
What are some of the symptoms of the code?
Symptoms of a P0065 engine code may include:
What are some of the common causes of the code?
Possible causes for this code may include:
What are some troubleshooting steps?
It is recommended to check for any technical service bulletins (TSBs) related to your vehicle. Accessing a known fix can save time and money during the diagnosis process.
Tools
When working with electrical systems, it is advisable to have the following basic tools:
Safety Tips
Basic Step #1
Refer to your service manual to locate the injector on your specific make and model. In most cases, the injector is mounted to the throttle body. Pay special attention to the vacuum lines and gaskets around the injector, as leaks in these areas can cause the injector to perform outside the desired range. Listen for any abnormal whistle noises around the hoses while the engine is running, indicating a leak. If you know how to use a vacuum gauge, monitor the vacuum within the intake system while the engine is running. Record your findings and compare them to the specified desired value.
NOTE: Replace any cracked vacuum hoses to prevent future issues.
Basic Step #2
Test the injector. The electrical values required for the injector vary depending on the make and model. Refer to your service manual for the specifications. This will likely involve using a multimeter to measure the resistance between the electrical pins on the injector.
NOTE: Always use appropriate multimeter lead connectors when testing pins/connectors to avoid bending pins and causing intermittent problems.
Basic Tip #3
Inspect the electrical connector on the injector for any corrosion or defects. Repair or replace it as necessary. Due to the injector’s location, the harness may be routed through tight areas where chafing can occur. Ensure that the harness and wires are in good condition and properly secured.
NOTE: Disconnect the battery before performing any electrical repairs.
Basic Step #4
Test the injector circuit. If possible and easy in your case, you may be able to disconnect the connector on the injector itself and the other end at the ECM. Check for continuity in the wires within the circuit using a multimeter. Another test you can perform is a voltage drop test to assess the wire’s integrity.
Basic Step #5
If your scan tool allows it, monitor the operation of the Air Assisted injector while the vehicle is running. Comparing the actual values to the specified desired values can help determine the issue.
