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  • The P1518 code stands for “Intake Manifold Runner Control (Stuck Open).” It indicates that the PCM has detected an issue in the IMRC.
  • Some common triggers for the code include a bad IMRC actuator, an open or shorted actuator, and electrical connection issues.
  • Symptoms to look out for are an illuminated check engine light and decreased engine performance.

Some modern vehicle’s come equipped with intake manifold runner control (IMRC) valves. These valves are incorporated in the system to allow intake manifold flaps to open and close. The IMRC improves your vehicle’s performance by making it possible for the intake manifold runner to change length through the butterfly valves.

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P1518 is a trouble code related to a fault in the IMRC. Did your scan tool read this code? We’ve gathered information to help you fix this issue.

What Does the P1518 Code Mean?

Diagnostic trouble code (DTC) P1518 stands for “Intake Manifold Runner Control (Stuck Open).”

intake manifold runner control problem triggers p1518 code
The code is set on Ford, Mercury, and Lincoln vehicles once the powertrain control module (PCM) senses a problem within the IMRC.

The code is set on Ford, Mercury, and Lincoln vehicles once the powertrain control module (PCM) senses a problem within the IMRC. Specifically, it is logged when the IMRC valve is closed but the IMRC monitor says it is open.

More in the IMRC

The IMRC is an electrically-actuated system. It’s equipped with two aluminum intake air passages. One passage is always open while the other one is equipped with a butterfly that opens and closes when necessary. The system also has a motorized actuator with internal switches used to send data to the PCM regarding linkage and plate position.

Once the PCM detects an issue within the system or that the valve is stuck open, it’ll log the P1518 code.

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For more technical information that can help you understand codes like P1518, read our technical discussion about IMRC systems.

What Are the Common Causes of the P1518 Code?

What Are the Common Symptoms of the P1518 Code?

How to Diagnose the P1518 Code

It’s not easy to diagnose a P1518 code. You’ll need adequate knowledge on the IMRC installed on your specific vehicle. Remember that vehicle engines can be structured differently depending on your ride’s automaker.

How to Fix the P1518 Code

Fixing the P1518 code can be complicated—especially if you’re not well-versed in auto repair. If you’re not an experienced DIYer, we recommend taking your ride to an auto repair shop. Let a mechanic who has experience clearing IMRC-related codes fix the issue for you.

If you’d really like to deal with the issue yourself, make sure to read up about the trouble code first before doing anything with your ride. Guides like those from Chilton can give you vehicle-specific information to help you repair your ride.

About The Authors
Written By Automotive and Tech Writers

The Research Team is composed of experienced automotive and tech writers working with (ASE)-certified automobile technicians and automotive journalists to bring up-to-date, helpful information to car owners in the US. Guided by's thorough editorial process, our team strives to produce guides and resources DIYers and casual car owners can trust.

Reviewed By Technical Reviewer at

Richard McCuistian has worked for nearly 50 years in the automotive field as a professional technician, an instructor, and a freelance automotive writer for Motor Age, ACtion magazine, Power Stroke Registry, and others. Richard is ASE certified for more than 30 years in 10 categories, including L1 Advanced Engine Performance and Light Vehicle Diesel.

Any information provided on this Website is for informational purposes only and is not intended to replace consultation with a professional mechanic. The accuracy and timeliness of the information may change from the time of publication.

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