P2008 on 2016-2019 Infiniti Q50: Intake Runner Control Fault Causes & Fixes

What's Unique About the 2016-2019 Infiniti Q50

For the 2016-2019 Infiniti Q50 and its platform-mate, the 2017-2019 Q60 with the same VR30DDTT engine, the P2008 code has a well-documented, platform-specific cause that is not a component failure. Infiniti issued multiple Technical Service Bulletins (TSBs) stating that due to a calibration error, the ECM can improperly store this code as a permanent fault. In many cases, the official fix is not to replace any parts, but to have an Infiniti dealer reprogram the ECM with updated software. This makes checking for TSBs the most critical first step in diagnosing a P2008 on this vehicle.

Diagnostic Flowchart

Tap your situation to follow the diagnostic path that matches what you're seeing on this vehicle.

Symptoms You May Notice

• Check Engine Light (MIL) illuminated
• Reduced engine power, especially at certain RPMs
• Hesitation or stumbling during acceleration
• Rough or fluctuating idle
• Decreased fuel economy
• Slightly delayed turbo response or feeling of 'lag'
• Hard starting in some cases

Most Likely Causes

1. ECM Software Calibration Error 🔴 High Probability Infiniti has issued multiple TSBs (ITB19-027a, ITB19-027, P9329) confirming that the original ECM software on 2016-2019 Q50 and 2017-2019 Q60 models is prone to improperly storing a P2008 code.
   How to confirm: An Infiniti dealership technician can connect the vehicle to a CONSULT-III plus diagnostic tool and check the current ECM part number against the list of outdated part numbers in Table B of TSB ITB19-027a. If the number matches the 'Before' column, the update is required.
   Typical fix: Reprogramming the Engine Control Module (ECM) with the latest software version. This was often covered under a voluntary service campaign.
   Est. part cost: $0
2. Faulty Intake Manifold Runner Control Solenoid 🟡 Medium Probability → Shop Engine Intake Manifold The solenoid (OEM Part #14935-5CA0A) is an electro-mechanical part in a high-heat environment, making it susceptible to internal coil failure over time. The Bank 1 solenoid is located on the passenger side of the engine, near the top, making it relatively accessible.
   How to confirm: After confirming the ECM software is up-to-date, a technician can test the solenoid. This involves checking its internal resistance with a multimeter (a typical reading for a good solenoid is between 20-40 ohms) and performing an active test with a capable scan tool to see if it 'clicks' when commanded. An open circuit (infinite resistance) indicates a failed solenoid.
   Typical fix: Replacement of the faulty solenoid for Bank 1. This part is sometimes also referred to as a boost control solenoid or vacuum control solenoid.
   Est. part cost: $50-$150
3. Wiring or Connector Issue ⚪ Low Probability Engine bay wiring can be susceptible to rodent damage or become brittle and crack from heat and age. The plastic locking tab on the solenoid's electrical connector can also break, leading to a poor connection.
   How to confirm: Visually inspect the wiring harness and connector leading to the IMRC solenoid for any signs of damage, such as chewing, chafing, or corrosion. A multimeter can be used to check for continuity and proper voltage at the connector pins with the key on.
   Typical fix: Repairing the damaged section of wire or cleaning/replacing the electrical connector pigtail.
   Est. part cost: $5-$50

Rare But Worth Checking

• Stuck or Binding Intake Runner Flaps: While P2008 is an electrical code, it's possible for a mechanical issue (like heavy carbon buildup causing the flaps to bind inside the intake manifold) to put extra strain on the electrical components, leading to failure. This is less common than a direct electrical or software fault and would typically be accompanied by other codes like P2006 (Stuck Closed) or P2007 (Stuck Open).

Diagnosis Steps

1. Read the trouble codes with an OBD-II scanner. Note if P2008 appears with P0087, P0101, or P0448, as this strongly suggests the TSB issue.
2. Crucial Step for this Vehicle: Contact an Infiniti dealer or a qualified shop with access to TSBs. Provide the VIN and ask them to check the current ECM Part Number against the tables in TSB ITB19-027a. If the software is outdated, the primary fix is an ECM reprogram.
3. If TSBs do not apply or the ECM software is already up to date, proceed with physical diagnosis.
4. Locate the Intake Manifold Runner Control solenoid for Bank 1 (passenger side on the 3.0t engine, near the top).
5. Visually inspect the solenoid's electrical connector and nearby wiring for any signs of damage, corrosion, or loose connections. Ensure the connector is fully seated and the locking tab is intact.
6. If a capable scan tool is available, perform an 'active test' to command the solenoid to open and close. Listen for an audible click from the solenoid.
7. Disconnect the solenoid and measure its internal resistance using a multimeter. Compare the reading to the manufacturer's specification (a healthy solenoid is typically in the 20-40 ohm range). An open circuit (infinite resistance) or a reading far outside the spec indicates a failed solenoid.
8. If the solenoid tests good, use a multimeter to check for correct voltage and ground at the connector with the key on, to ensure the ECM is sending a signal.
9. If wiring and the solenoid are confirmed to be good, the issue may be mechanical binding within the intake manifold, which requires more intensive disassembly to inspect.

Parts You'll Likely Need

• Intake Manifold Runner Control Solenoid (OEM #14935-5CA0A / 14935-5CA0B) — If the issue is not software-related, this solenoid is the most likely component to fail electrically, causing the P2008 open circuit code.
  Trusted brands: Infiniti OE, Hitachi (VCS0002)
  OEM price range: $100-$180
  Aftermarket price range: $50-$120

Related Codes That Often Appear With This One

• P0087 — This Fuel Rail/System Pressure code is listed in the same TSBs (ITB19-027a, P9329) as P2008, indicating they can both be triggered by the same ECM calibration error.
• P0101 — This Mass Air Flow (MAF) sensor code is also mentioned in the TSBs (ITB19-027a, P9329) as being related to the ECM software issue.
• P0448 — This EVAP System Vent Control Circuit code is another one grouped with P2008 in the Infiniti TSBs (ITB19-027a, P9329) that can be resolved with an ECM reprogram.

Technical Service Bulletins (TSBs) & Recalls

• ITB19-027a: MIL ON WITH DTC P0087, P0101, P0448, OR P2008
• ITB19-027: MIL ON WITH DTC P0087, P0101, P0448, OR P2008
• P9329/P9344/P9346/P9348/P9350: VOLUNTARY EMISSIONS SERVICE CAMPAIGN ECM REPROGRAMMING

Platform-Specific Known Issues

• ECM Calibration Error: Per Infiniti TSBs ITB19-027a, ITB19-027, and P9329, the ECM may improperly store a permanent diagnostic trouble code for P2008 due to software calibration errors. The recommended fix is an ECM reprogram.
• Solenoid Accessibility: The Bank 1 (passenger side) IMRC solenoid is located in a relatively easy-to-access position on top of the engine, making it a feasible DIY replacement for those with basic tools.

Scan Tool Commands That Help

• Infiniti CONSULT-III plus: Active Test for Intake Manifold Runner Control — After confirming the TSB for the ECM reprogram does not apply, a technician uses this function to command the Bank 1 IMRC solenoid to actuate. Navigating to the Engine system, then the 'Active Test' tab allows for this bidirectional control. A clicking sound confirms the solenoid and its wiring are receiving the command; no sound points to a dead circuit (wiring or solenoid) or a failed ECM driver.

Wiring & Ground Locations

• E134, E136 — Located on the right (passenger) side rear of the engine compartment.. These are primary ground points for engine components on Bank 1, including the ECM itself. A corroded or loose ground at these locations can cause a variety of intermittent electrical faults and open circuits, including P2008. Checking these grounds is a key step when diagnosing a persistent electrical issue that isn't resolved by replacing the component.