Fix P2008: Mechanic’s solutions that WORKED

The code P2008: Intake Manifold Runner Control Circuit/Open Bank 1 points out a fault in the Intake Manifold Runner Control Circuit, and most likely is caused by a malfunctioning actuator, electrical issues, or blockages in the manifold runner.

P2008 quick overview

Meaning	P2008: Intake Manifold Runner Control Circuit/Open Bank 1
Is it serious?	This code can be serious as it may affect the vehicle’s fuel economy and performance, potentially leading to increased emissions and engine damage over time.
Possible causes	– Faulty Intake Manifold Runner Control (IMRC) actuator/solenoid – Open or short in the IMRC harness – Poor electrical connection in the IMRC circuit – Faulty Powertrain Control Module (PCM)
How to diagnose?	Check IMRC Actuator/Solenoid: Inspect the IMRC actuator for signs of damage or malfunction. Examine Wiring and Harness: Look for any open, shorted, or damaged wires in the IMRC harness. Test Electrical Connections: Ensure all electrical connections in the IMRC circuit are secure and free of corrosion. Inspect Intake Manifold Runner: Verify that the intake manifold runner moves freely and isn’t stuck. Consult Technical Service Bulletins: Look for any manufacturer bulletins for known issues and recommended solutions. Consider PCM Check: As a last resort, evaluate the PCM for any faults, as it’s the least likely cause but still a possibility.

How to fix P2008 – learn from mechanics

I looked into P2008 service cases at iatn.com website where in the private forums the mechanics seek advice from other mechanics. I looked up a bunch of cases to help you decide how to fix your issue and see what would a real mechanic do to solve it.

Case #1: Mercedes

Vehicle Information:
2003 Mercedes-Benz CLK320 3.2L

Issue + Repair History:

• Persistent MIL with codes indicating O2 sensor heater issues.
• Replaced both upstream O2 sensors and MAF sensor.
• Code P2008 kept returning despite replacements.

Other OBD2 Codes + Test Results:

• P2008

Suggestions to Fix Issue:

• Use OE O2 sensors as aftermarket ones might have different wattage ratings causing issues.
• Check for any chassis wiring problems as per TSBs related to these codes.
• Ensure the use of a reliable scan tool for accurate diagnostics.

Final Fix:

• Replaced the MAF with a new one, resolving the issue. The previously used MAF, though thought to be good, was faulty.

Case #2: Dodge

Vehicle Information:
2003 Dodge Intrepid SXT 3.5L

Issue + Repair History:

• Car returned after an engine replacement but wouldn’t start.
• PCM connector was loose and was reconnected, but the issue persisted.
• Code P2008 (short runner solenoid circuit) was present.

Other OBD2 Codes + Test Results:

• P2008: Short runner solenoid circuit

Suggestions to Fix Issue:

• Check the location and condition of the short runner valve, typically found on the intake near the front.
• Verify all powers and grounds to the PCM, ensuring no terminals are spread or damaged.
• Consider the possibility of engine timing issues or sensor/wiring problems. Unplugging the cam sensor may help diagnose this.
• Assess the possibility of a damaged PCM due to intermittent connection and voltage spikes.

Final Fix:

• The problem was resolved by replacing the PCM.

Case #3: Chrysler

Vehicle Information:
2004 Chrysler Pacifica 3.5L

Issue + Repair History:

• Customer reported hesitation and occasional stalling at startup.
• Only code present was P2008 for the short runner valve in the intake plenum.
• Timing belt and water pump replaced last year.

Other OBD2 Codes + Test Results:

• P2008: Short Runner Valve Solenoid Circuit

Suggestions to Fix Issue:

• Check the short runner valve solenoid for binding and proper operation.
• Inspect the actuator and circuits for any issues.
• Consider carbon buildup in the intake as a potential cause.
• Review Chrysler TSBs related to this code for further guidance.

Final Fix:

• Discovered the two-wire connector to the Short Runner Valve Actuator was disconnected.
• Reconnected the actuator, and though the SRV was sticking, the immediate problem of the P2008 code was resolved.
• Informed customer that a new plenum might be needed if drivability issues persist due to the SRV sticking.

Case #4: Volkswagen

Vehicle Information:
2011 Volkswagen Jetta TDI 2.0L

Issue + Repair History:

• The vehicle had an MIL with codes related to the intake manifold runner.
• During diagnostics, voltage at runner control valve pins 4 and 5 was found to be pulsing from 0 to 4.36V.
• Owner sought advice on whether this pulsing voltage is normal.

Other OBD2 Codes + Test Results:

• P2015: Intake manifold runner position
• P2008: Intake manifold runner control

Suggestions to Fix Issue:

• Check if the pulsing signal is due to the runner position sensor trying to command movement.
• Consider PCV oil/carbon vapor buildup as a cause of intake manifold runner valve sticking.
• Investigate the use of external stop fixes or replacement of plastic bushings in the flap shaft.
• Confirm whether the voltage behavior is normal or indicative of a glitch, possibly by using a scope.
• Check for any recall or extended warranty covering the intake manifold.

Final Fix:

• The runner rod was found to be broken. The problem was fixed by addressing this issue.

Case #5: Ford

Vehicle Information: 2006 Ford Focus ZX4 2.0L

Issue + Repair History:

• Persistent MIL with codes P2008, P2006, and sometimes P2004.
• Previous shop replaced the IMRC actuator; it’s functioning.
• The intake valve doesn’t feel restricted or binding.
• Replaced PCM, tried known good IMRC solenoid, and adjusted vacuum source.
• Conducted extensive wire integrity checks.

Other OBD2 Codes + Test Results:

• P2008: IMRC Fault
• P2006: IMRC
• P2004: IMRC
• Manifold Vacuum Readings: Idle and Cruise at 22 inches.

Suggestions to Fix Issue:

• Check for binding linkages or broken intake manifold.
• Consider a potentially defective intake manifold with possible broken runner flaps.
• Update intake and clean out the throttle body.

Final Fix:

• After resetting and starting over, discovered the PCM driver wire to the actuator solenoid was grounding intermittently, likely due to heat affecting the wire. Ran a new wire instead of tracing the original due to extensive time already invested.

Advice	Diagnostic Step
Check for binding linkages or broken intake manifold	Inspect the physical components of the IMRC system for any signs of wear or damage.
Examine the intake manifold, especially the runner flaps	Investigate the integrity of the intake manifold and runner flaps for any breakage or malfunction.
Update intake and clean the throttle body	Consider replacing or updating the intake system and cleaning the throttle body to ensure optimal airflow.
Test wiring integrity	Conduct thorough checks on the wiring, looking for shorts, opens, or grounding issues, especially related to the IMRC actuator solenoid.
Consider replacing the IMRC actuator if malfunctioning	If diagnostics indicate, replace the IMRC actuator to ensure proper functioning of the system.
Reset and start over if necessary	Sometimes starting the diagnostic process from the beginning can uncover overlooked issues.