P2018 – Intake Manifold Runner Position Sensor/Switch Circuit (Bank 2)

The P2018 OBD-II code indicates a problem with the intake manifold runner position sensor/switch circuit on bank 1. This code is considered a generic powertrain code that applies to many vehicles, but the specific repair steps may vary by make and model.

Urgency and Severity

When the P2018 code is triggered, it's generally safe to continue driving in the short term as it typically does not indicate an immediately dangerous situation. However, you may notice reduced engine performance and fuel efficiency. It's best to diagnose and fix the issue as soon as possible to prevent potential long-term engine damage. If the problem worsens and the Check Engine light begins flashing, you should stop driving and have the vehicle towed to a mechanic.

Parts Involved

The main components related to the P2018 code are:

• Intake Manifold Runner Control (IMRC) valve/sensor: Controls airflow into the engine at various RPMs
• Powertrain Control Module (PCM): The vehicle's main computer that monitors the IMRC sensor

Common Causes

Typical causes of a P2018 code include:

1. Faulty IMRC valve or actuator
2. Damaged wiring or loose/corroded connectors
3. Stuck or binding throttle body/plates
4. Rarely, a faulty PCM

Diagnostic Steps

1. Check for any other codes, especially performance-related ones, and diagnose those first.
2. Visually inspect the IMRC valve, wiring, and connectors for obvious damage.
3. Use a scan tool to monitor IMRC voltage signals and compare to manufacturer specs.
4. Perform IMRC component tests per the service manual.

Repair Solutions

• Replace or repair the faulty IMRC valve/sensor
• Repair damaged wiring or connectors
• Clean throttle body and plates
• Replace the PCM if faulty (rare)

Prevention

Regular maintenance, including replacing air filters and cleaning the throttle body, can help prevent IMRC issues. Fixing intake leaks promptly is also important.

Repair Costs

• IMRC valve/sensor: $85-$350 ($75-€315)
• Throttle body cleaning: $75-$200 (€67-€180)
• Wiring repairs: $100-$300 (€90-€270)
• PCM replacement: $500-$1500 (€450-€1350) plus programming

Related Codes

Other codes that may appear with P2018:

• P0106 (MAP sensor)
• P0113 (IAT sensor)
• P0171/P0174 (lean condition)

These codes indicate problems with the air/fuel mixture, which the IMRC helps control.

I hope this technical guide helps your readers better understand the causes, diagnosis, and repair of the P2018 engine code. Let me know if you need any other details to make the article more useful for your audience of mechanics and engineers.

Frequently Asked Questions About the P2018 Engine Code

What does the P2018 code mean?

The P2018 OBD-II code indicates that the engine control module (ECM) has detected an intermittent problem with the intake manifold runner position sensor/switch circuit on bank 1. This sensor helps control the amount of air flowing into the engine at various RPMs.

Is it safe to drive with a P2018 code?

In most cases, you can continue driving in the short term with a P2018 code. However, you may experience reduced engine performance and fuel efficiency. It's best to diagnose and fix the issue as soon as possible to prevent potential long-term engine damage.

What are the common symptoms of a P2018 code?

Common symptoms include:

• Check Engine light illuminated
• Reduced engine power
• Rough idle or occasional misfires
• Decreased fuel economy

What causes a P2018 code?

Typical causes of a P2018 code include:

1. Faulty intake manifold runner control (IMRC) valve or actuator
2. Damaged wiring or loose/corroded electrical connectors
3. Stuck or binding throttle body/plates
4. Rarely, a faulty PCM

How do you diagnose a P2018 code?

Key diagnostic steps:

1. Scan for other codes and address those first
2. Visually inspect the IMRC components and wiring for damage
3. Use a scan tool to monitor IMRC sensor voltage
4. Perform IMRC component tests per the service manual

How much does it cost to fix a P2018 code?

Repair costs can vary but estimates include:

• IMRC valve/sensor replacement: $85-$350
• Throttle body cleaning: $75-$200
• Wiring repairs: $100-$300
• PCM replacement: $500-$1500+

Can a vacuum leak cause a P2018 code?

Yes, intake manifold vacuum leaks can cause the IMRC sensor to read incorrectly and trigger a P2018 code. Inspect the intake manifold, vacuum lines, and gaskets for leaks.

Can a bad mass airflow sensor cause P2018?

Indirectly, yes. A faulty MAF sensor can cause incorrect air readings and lead to issues with the IMRC system, potentially triggering a P2018 code along with MAF-related codes like P0101.

How do you replace the intake manifold runner control valve/sensor?

The exact procedure varies by vehicle, but the general steps are:

1. Disconnect the negative battery cable
2. Remove the intake manifold
3. Unbolt the IMRC valve/sensor and transfer components to the new part
4. Install the new IMRC valve/sensor and reassemble
5. Clear codes and test

Can a P2018 code cause a misfire?

Yes, a failing IMRC system can disrupt the air/fuel mixture leading to lean misfires, often on one bank of the engine. Misfires will usually have their own codes like P0300-P0308.

What is the difference between IMRC and CMCV?

IMRC (intake manifold runner control) and CMCV (charge motion control valve) are similar systems that alter airflow into the engine. IMRC controls air at different RPMs while CMCV is used to create swirl at lower RPMs. Some engines use one or both systems.

Can carbon buildup cause a P2018 code?

Yes, carbon deposits on the IMRC valves or throttle body can cause them to stick and bind, triggering a P2018 code. Cleaning these components may resolve the issue if no parts are faulty.

Can you clean an IMRC valve or does it need to be replaced?

In many cases, cleaning the IMRC valves with throttle body cleaner can resolve sticking and binding issues. However, if the valves or actuator are faulty, they will need to be replaced.

How often should the IMRC valve be cleaned?

There is no specific maintenance schedule for cleaning IMRC valves. However, if you experience symptoms or codes related to IMRC, cleaning the valves and throttle body every 50,000-75,000 miles can help prevent recurring issues.

What other codes commonly appear with P2018?

Related codes can include:

• P0106 (MAP sensor)
• P0113 (IAT sensor)
• P0171/P0174 (lean condition)
• P0300-P0308 (misfire codes)
• P2008 (IMRC stuck open)
• P2017 (IMRC stuck closed)

Can a software update fix a P2018 code?

In rare cases, a glitchy PCM could trigger a false P2018 code that could be resolved with a software update at the dealer. However, software is unlikely to resolve codes caused by faulty components or wiring issues.

How do you test IMRC wiring?

To test IMRC wiring:

1. Unplug the IMRC sensor
2. Set your multimeter to ohms
3. Check continuity on each wire between the sensor and PCM
4. Replace any wires showing open or short circuits

What is the location of the IMRC valve/sensor?

The IMRC valve/sensor is typically located on the intake manifold near the throttle body. The exact location varies by vehicle make and model. Consult a service manual or repair database for vehicle-specific information.

Can a faulty IMRC valve damage the engine?

A stuck open IMRC valve can lead to an excessively lean condition and misfires, which can damage the catalytic converter over time. A stuck closed valve can cause hesitation and power loss. Address IMRC issues promptly to avoid potential damage.

How long does it take to replace an IMRC valve/sensor?

Replacement time depends on the vehicle and technician skill level. It typically takes 2-4 hours to replace an IMRC valve/sensor, as the intake manifold usually needs to be removed to access it.

What should you do if a P2018 code keeps coming back after repairs?

If a P2018 code returns after replacing the IMRC valve/sensor, there may still be an issue with the wiring, throttle body, or PCM. Recheck all system components, clear the codes, and retest. Consult with a professional technician for recurring codes that are difficult to diagnose.