Error Code P2004 is defined as Intake Manifold Runner Control Stuck Open Bank 1. This code means the IMRC or Intake Manifold Runner Control is stuck in the open position in Bank 1.

This trouble code is a generic trouble code, which means it applies to all vehicles made since 1996 up to present, especially those equipped with OBD-II system. It is, however, more common among a set of manufacturers, such as Dodge, Ford, Mazda, Mercedes Benz, Jeep, etc. Though generic, specifications on the definition, troubleshooting and repairs vary from one make and model to another.

Definition

The PCM (powertrain control module, also known as ECM or Engine Control Module in other vehicle makes) provides information to the IRMC about the present driving conditions. The IRMC then uses this information to regulate the amount of airflow that is permitted into the intake system. The regulation in the intake airflow reduces harmful emissions, improves air/fuel mixture, and improves the fuel efficiency of the vehicle.

IRMC Components include:

  • Electric solenoid
  • Vacuum actuator
  • Butterfly valve plates
  • Air passage to each cylinder
  • Linkage rods connected to the intake manifold butterfly plate level
  • Return springs that hold the butterfly valve plates open

Error Code P2004 is stored when the PCM has detected that the (IMRC) actuator for engine bank 1 is stuck in the open position. Bank 1 denotes that the problem has occurred in the bank of the engine that contains the number one cylinder.

Related Codes include:

  • P2005: IMRC Stuck Open Bank 2
  • P2006: IMRC Stuck Closed Bank 1
  • P2007: IMRC Stuck Closed Bank 2
  • P2008: IMRC Circuit Open Bank 1
  • P2009: IMRC Circuit Low Bank 1
  • P2010: IMRC Circuit High Bank 1
  • P2011: IMRC Circuit Open Bank 2
  • P2012: IMRC Circuit Low Bank 2
  • P2013: IMRC Circuit High Bank 2
  • P2014: Intake Manifold Runner Position Sensor/Switch Circuit Bank 1
  • P2015: Intake Manifold Runner Position Sensor/Switch Circuit Range/Perf Bank 1
  • P2016: Intake Manifold Runner Position Sensor/Switch Circuit Low Bank 1
  • P2017: Intake Manifold Runner Position Sensor/Switch Circuit High Bank 1
  • P2018: Intake Manifold Runner Position Sensor/Switch Circuit Interm Bank 1
  • P2019: Intake Manifold Runner Position Sensor/Switch Circuit Bank 2
  • P2020: Intake Manifold Runner Position Sensor/Switch Circuit Range/Perf Bank 2
  • P2021: Intake Manifold Runner Position Sensor/Switch Circuit Low Bank 2
  • P2022: Intake Manifold Runner Position Sensor/Switch Circuit High Bank 2
  • P2023: Intake Manifold Runner Position Sensor/Switch Circuit Interm Bank 2

Symptoms

As with other error codes, this code activates the Check Engine light and registers the code to the vehicle’s memory system. Other symptoms include:

  • Increase in fuel consumption
  • Rough running
  • Decrease in engine torque
  • Engine may surge or sputter

Possible Causes

Since the IRMC involves a lot of components, there are a lot of things that could go wrong in the IRMC. Possible causes for this code include:

  • Defective IMRC solenoid
  • Short, breaks, or frayed wires in the IMRC solenoid
  • Open or shorted IMRC solenoid
  • Corrosion in the IMRC solenoid
  • Broken or loose IMRC butterfly valve plate screws
  • Broken IRMC IMRC butterfly valve plate
  • IRMC butterfly valve plate is disconnected from the IMRC actuator
  • Clogged vacuum control solenoid vacuum filter
  • Trapped debris in vacuum control solenoid
  • Broken or disconnected vacuum lines
  • Carbon build up in the IMRC butterfly valve plates
  • EGR (Exhaust Gas Recirculation) valve trouble codes stored in the PCM
  • MAF sensor trouble codes stored in the PCM
  • BARO sensor trouble code stored in the PCM

Hot to Check

As with other error codes, diagnosing this code requires the use of an OBD-II scanner.  Technicians collect the freeze frame data and other stored codes in the PCM. If there are other trouble codes present, such as codes referring to the EGR valve, MAF sensor, and BARO sensor, then they must be diagnosed and repaired first.

Next is to conduct a visual inspection of all wirings. Check for breaks, shorts, and frayed wires. Any faults in the wires must be fixed.

Then, inspect the IMRC solenoid and look for signs of damage and corrosions. Repair or replace damaged connectors as necessary.

Check the vacuum lines and hoses. Repair or replace as necessary.

Next, check the IMRC butterfly valve plates, ensure proper connection.

Check the EGR valve and look for signs of carbon build up. Carbon build up can get into the IMRC solenoid and cause it to be defective.

Clear the codes and then retest the vehicle for the Error Code P2004. Test the IMRC solenoid using the scan tool.

Open and close the IMCR solenoid using the scanner. If the solenoid doesn’t respond, then it must be replaced.

How to Fix

Despite the complexity of the IMRC and the many possible causes for this code, repair can be straightforward. Of course, a thorough diagnosis is crucial for efficient repair. Common fixes include:

  • Replacement of the IMRC solenoid
  • Repair or replacement of the shorted, broken, or frayed IMRC solenoid wiring
  • Repair or replacement of the open or shorted IMRC solenoid circuitry
  • Repair or replacement of the corroded IMRC solenoid connector
  • Repair or replacement of IMRC valve plate hardware, if necessary
  • Repair or replacement of loose or damaged vacuum lines
  • Replacement of the IMRC valve plate (before you can do this, intake manifold assembly must be replaced first)
  • Thorough diagnosis and repair of the EGR valve, MAF sensor, and/or BARO trouble codes (if present).

Error Code P2004 can be serious if the IMRC butterfly valve plate hardware becomes loose and falls off into the engine. This can cause serious engine damage, and potentially engine failure. Thus, it is important to inspect thoroughly and repair this code as soon as possible.