Fix P2006: Mechanic’s solutions that WORKED

The P2006: Intake Manifold Runner Control Stuck Closed Bank 1 indicates that the Intake Manifold Runner Control (IMRC) on Bank 1 of the engine is stuck in the closed position. This control regulates air flow to the engine’s cylinders, optimizing performance. When it’s stuck, it hinders the engine’s ability to operate efficiently, potentially leading to reduced power and higher emissions.

P2006 quick overview

Meaning	P2006: Intake Manifold Runner Control Stuck Closed Bank 1
Is it serious?	This code can be moderately serious, as it may affect engine performance, fuel efficiency, and emissions.
Possible causes	– Faulty Intake Manifold Runner Control (IMRC) – Blocked or dirty intake manifold runner – Malfunctioning IMRC actuator – Vacuum leak in the intake system – Electrical issues in the IMRC circuit
How to diagnose?	Inspect IMRC: Look for any physical obstructions or dirt in the intake manifold runner. Check Actuator: Examine the IMRC actuator for damage or operational issues. Test Vacuum System: Ensure no vacuum leaks are present in the intake system. Electrical Diagnosis: Check the electrical connections and wiring to the IMRC. Monitor Voltage: Measure voltage at the IMRC during Key On Engine Off (KOEO) for anomalies. Evaluate Harness Routing: Ensure the harness is correctly routed to avoid mechanical interference. Consider Replacement: If the IMRC actuator is faulty, consider replacing it.

How to fix P2006 – learn from mechanics

I looked into P2006 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: Mazda

Vehicle Information: 2008 Mazda CX-7 Grand Touring 2.3L

Issue + Repair History:

• Had a P2006 code (IMRC stuck off) following a hard front-end collision.
• The intake flap operates correctly, but the actuator lever doesn’t contact the switch indicating flap position.

Other OBD2 Codes + Test Results: P2006 – IMRC Stuck Off

Suggestions to Fix Issue:

• Obtain a visual reference, such as a picture or video, of the intake assembly to understand the correct positioning.
• Consider replacing the intake manifold if the plastic lever or switch mechanism is damaged.
• Explore custom repair options if a standard replacement is not preferred or feasible.

Final Fix: The issue was identified as a missing plastic lever around the shaft for the intake flap, which contacts the switch. The customer decided not to proceed with the suggested repair of replacing the intake to rectify the issue.

Case #2: Audi

Vehicle Information: 2007 Audi A6 Quattro 3.2L

Issue + Repair History:

• Check engine light on, but no performance issues noted.
• Retrieved codes P2006 and P2007.
• Visual inspection of vacuum hoses and lines showed no issues.
• Tested vacuum solenoid to intake actuators, which worked fine at about 15 inches of vacuum, but only 10 inches of vacuum at the inlet side of the solenoid.

Other OBD2 Codes + Test Results:

• P2006 – IMRC Stuck Off
• P2007 – None found
• Vacuum at idle: 10 inches at manifold port by vacuum solenoid that feeds actuators
• Vacuum at vacuum pump at idle: 14 inches

Suggestions to Fix Issue:

• Conduct a smoke test to check for vacuum leaks.
• Check for TSBs related to IMRC position sensor failures.
• Consider removing the intake plenum to verify actuators’ movement and check for carbon build-up on intake valves.
• Examine the vacuum line, especially near the power steering bottle, for cracks or damage.

Final Fix: The problem was traced to a crack in the vacuum line at the front left side, going to a vacuum canister located on the left inner fender well. A smoke test was used to identify the leak. Repairing the cracked vacuum line resolved the codes P2006 and P2007.

Case #3: Ford

Vehicle Information: 2007 Ford F-150 XLT 5.4L

Issue + Repair History:

• Truck was logging a P2006 code (Intake Runner Control Stuck Closed Bank 1).
• Initially found bank one runner control rod off and replaced the IMRC motor.
• After repairs, experienced bogging under acceleration and backfiring.
• Re-flashed ECM, rechecked installation and vacuum hoses, and checked for cat back pressure.

Other OBD2 Codes + Test Results: P2006 – Intake Runner Control Stuck Closed Bank 1 Vacuum at idle: 10 inches at manifold port by vacuum solenoid

Suggestions to Fix Issue:

• Conduct a KOEO (Key On Engine Off) test to watch the IMRC motor run and ensure proper operation.
• Check booster hose connections and oil pressure for potential cam phaser issues.
• Consider possibility of plugged catalytic converters.
• Verify throttle body and vacuum line connections.
• Unplug MAF sensor and drive to see if the problem improves.

Final Fix: The problem was traced to a clearance issue where the brake booster hose was catching the clip holding the rod on the IMRC, causing the P2006 code. Adjusting the placement of the brake booster hose and ensuring enough clearance for the rods to move freely resolved the issue.

Case #4: Mercedes

Vehicle Information: 2006 Mercedes-Benz ML350 3.5L

Issue + Repair History:

• Check engine light on with concerns about cleaning or replacing the intake manifold.
• Questioned the possibility of cleaning the swirl flaps in the intake manifold.

Other OBD2 Codes + Test Results: P2006 – Intake Manifold Swirl Flaps Binding

Suggestions to Fix Issue:

• Consideration of whether cleaning the swirl flaps is feasible or if replacement is necessary.
• Checking for a broken plastic piece connecting the rods in the intake manifold.
• Looking for a used intake manifold as a more cost-effective solution.
• Awareness of potential for broken exterior arm and internal bushing falling into the engine.

Final Fix: The vehicle was repaired by replacing the intake manifold. Upon removal, it was discovered that the bushings for the left side swirl flaps were missing, causing the flaps to bind and break the actuator rod. This led to the decision to replace the entire intake manifold.

Case #5: Lincoln

Vehicle Information: 2005 Lincoln Navigator 5.4L

Issue + Repair History:

• Navigator had an engine replacement at another shop.
• KOEO (Key On Engine Off) code P2006 (IMRC stuck closed).
• The intake manifold was removed for inspection due to hesitation issues.
• No harness problem found, but the IMRC motor was suspected to be faulty.

Other OBD2 Codes + Test Results: P2006 – IMRC Stuck Closed

Suggestions to Fix Issue:

• Consider disassembling the motor assembly to inspect or replace plastic gears.
• Check if the flaps in the intake manifold are moving properly.
• Inspect the wiring to the IMRC motor for possible breakage or damage.
• Rewire the connector with a new harness if necessary, following the vehicle’s schematic.
• Verify the connection of the 4 wires of the IMRC motor.

Final Fix: The issue was resolved by replacing the IMRC actuator. It was initially still not functioning due to a misrouted harness, which caused the linkage to bind. After rerouting the harness correctly, the actuator worked, and the vehicle’s performance improved. The diagnosis highlighted the importance of ensuring the correct routing of the harness to avoid mechanical binding.

Advice	Description of Diagnostic Step
Check Intake Manifold Runner Control (IMRC)	Inspect the IMRC for proper operation and ensure it’s not stuck or binding.
Inspect Wiring and Connectors	Examine electrical connections to the IMRC for damage or loose connections.
Examine the Actuator	Check the IMRC actuator for signs of failure or malfunction.
Inspect for Physical Obstruction	Look for any physical obstruction or dirt in the intake manifold runner.
Perform Electrical Diagnosis	Conduct a thorough electrical diagnosis, including checking voltage and ground at the IMRC motor.
Test Vacuum System	Ensure there are no vacuum leaks in the intake manifold system affecting the IMRC.
Evaluate Harness Routing	Check if the harness is correctly routed to avoid binding or mechanical interference.
Consider Actuator Replacement	If the actuator is found to be faulty, consider replacing it.