P2440 on 2011-2014 Audi Q5: Secondary Air Valve Stuck Open Causes & Fixes

What's Unique About the 2011-2014 Audi Q5

On these Audi Q5 models with the 3.0T and 3.2L V6 engines, the P2440 code is a well-documented issue. The problem is so common that Audi has issued multiple Technical Service Bulletins (TSBs) about it. The system uses vacuum-operated 'combi valves' (combination valves) which are known to fail or get stuck with carbon. The TSBs specifically point to either a defective combi valve (if the code is for one bank) or a faulty N112 vacuum solenoid (if codes for both banks appear together) as the primary culprits, providing a clear diagnostic path.

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) is on
• Vehicle will fail an emissions test
• Audible vacuum cleaner or jet engine-like noise from the engine bay for 30-60 seconds on a cold start if the air pump is affected.
• In rare cases, a brief rough idle on a cold start.

Most Likely Causes

1. Defective Secondary Air Injection (Combi) Valve (Bank 1) 🔴 High Probability This is the most common cause cited directly by Audi in TSB 2040403/5 when only a single bank code like P2440 is present. The valve's internal diaphragm can tear, or it can get stuck with carbon deposits, holding it open.
   How to confirm: Bank 1 is the passenger side on North American vehicles. With the engine cold, disconnect the vacuum line from the valve and apply vacuum with a hand pump. It should hold vacuum and you should hear it actuate. If it doesn't hold vacuum, the diaphragm is torn. If it holds vacuum but the code persists, it may be mechanically stuck. Feeling for exhaust backflow from the air pump inlet hose after the pump shuts off is another indicator.
   Typical fix: Replace the Bank 1 combi valve and the associated gasket.
   Est. part cost: $150-$280
2. Defective Vacuum Solenoid Valve (N112) 🟡 Medium Probability This is the second scenario outlined in Audi's TSB. This single solenoid controls the vacuum supplied to both combi valves. If it fails, it can't properly command the valves to close. The TSB explicitly states this is the likely cause if both P2440 and P2442 are stored together.
   How to confirm: Test the solenoid for proper electrical resistance (typically 10-40 ohms) and function. Check for vacuum at the solenoid's inlet and outlet ports when it is commanded on and off with a scan tool. 🎬 Watch: How to locate and replace the vacuum solenoid valve. A YouTube video by 'How to Replace your secondary Air Injection Valve on your audi 3.2' shows its location and replacement.
   Typical fix: Replace the vacuum solenoid valve.
   Est. part cost: $40-$80
3. Cracked or Leaking Vacuum Hoses 🟡 Medium Probability The plastic and rubber vacuum lines in the engine bay become brittle over time due to heat cycles and can crack or break, causing a loss of vacuum signal to the combi valve. This can prevent the valve from closing as commanded.
   How to confirm: Visually inspect all vacuum lines connected to the combi valves and the control solenoid for cracks, breaks, or loose connections. A smoke test can also quickly identify hard-to-see leaks. Pay close attention to the plastic tubing near the pump itself, as it is known to become brittle.
   Typical fix: Replace the damaged section of vacuum hose.
   Est. part cost: $10-$30

Rare But Worth Checking

• Clogged Secondary Air Ports in Cylinder Head: This is a very well-known issue on VAG 3.0T/3.2L engines, but it typically causes 'Insufficient Flow' codes (P0491/P0492), not a 'Stuck Open' code. However, severe carbon buildup could theoretically interfere with valve operation. 🎬 See a detailed explanation of carbon buildup in the air ports. This is an expensive repair requiring significant labor and special tools (Audi tool VAS6825 or an aftermarket equivalent) to clean the ports.
• Faulty Engine Control Module (ECM) Software: An older TSB for the 3.2L engine (TSB 24 12 20 / 2025547/8) suggests that an ECM software update may be required to fix erroneous P2440/P2442 codes. This is less likely than a mechanical failure but should be considered if the vehicle has never had its software updated at a dealership, especially if no mechanical faults can be found.

Diagnosis Steps

1. Read the codes with an OBD-II scanner to confirm P2440 is present. Check if P2442 is also present.
2. If both P2440 and P2442 are present, focus diagnosis on the shared vacuum solenoid valve (Part No. 037906283C) and its wiring/vacuum supply, per Audi TSB 2040403.
3. If only P2440 is present, begin by visually inspecting the vacuum lines running to the Bank 1 (passenger side) combi valve for any obvious cracks, breaks, or disconnections.
4. Locate the Bank 1 combi valve at the rear of the passenger-side cylinder head.
5. Use a handheld vacuum pump to test the combi valve. Disconnect the vacuum line and apply vacuum. The valve should hold vacuum and you should hear/feel it actuate. If it does not hold vacuum, the valve's diaphragm is torn and the valve must be replaced.
6. If the valve holds vacuum, check the vacuum supply line itself while the engine is running to ensure the solenoid is providing vacuum when commanded (and releasing it when not).
7. If vacuum lines and the combi valve check out, the issue may be with the solenoid or wiring, even if only one code is present. Check for constant power or ground at the solenoid connector.

Parts You'll Likely Need

• Secondary Air Injection (Combi) Valve - Bank 1 (Left/Driver side for part ordering) (OEM #06E131101K) — This is the most frequent failure point for a P2440 code, as identified by Audi's own service bulletins. Note: Part catalogs list this as the 'Left' valve.
  Trusted brands: Pierburg (OEM), Dorman, Vaico
  OEM price range: $250-$300
  Aftermarket price range: $150-$220
• Secondary Air Injection Solenoid Valve (N112) (OEM #037906283C) — This solenoid controls the vacuum to both combi valves. It's the primary suspect if both P2440 and P2442 codes are present.
  Trusted brands: Pierburg (OEM), Bosch
  OEM price range: $60-$80
  Aftermarket price range: $30-$50
• Combi Valve Gasket (OEM #06E131120C) — This gasket is required when replacing the combi valve and should not be reused to prevent exhaust leaks.
  Trusted brands: Victor Reinz, Elring
  OEM price range: $10-$15
  Aftermarket price range: $5-$10

Related Codes That Often Appear With This One

• P2442 — This is the code for 'Secondary Air Injection System Switching Valve Stuck Open Bank 2'. Audi's TSB 2040403/5 explicitly states that if both P2440 and P2442 appear at the same time, the common cause is the single vacuum solenoid (N112) that controls both valves.

Technical Service Bulletins (TSBs) & Recalls

• A011519 2040403 / 01 17 48 2040403/5: States that for DTC P2440 and/or P2442, the cause is either a defective combi valve (if one code is present) or a defective vacuum solenoid (if both codes are present).
• 01 14 54 2025547/4 (and newer revisions like 24 12 20): An older TSB for the 3.2L engine that suggests an ECM software update may be needed if P2440 and P2442 are stored and no mechanical fault is found.
• TPI 2033001: While not for P2440 specifically, this TSB addresses the related P0491/P0492 'Insufficient Flow' codes caused by carbon-clogged cylinder head ports on the 3.0T and 3.2L engines, a major related issue for this platform.

Platform-Specific Known Issues

• Audi Technical Service Bulletin #A011519 2040403 (and its revisions like 2040403/5) directly addresses P2440 and P2442 on these vehicles. It states: 'One of the combi valves is defective or the vacuum solenoid is defective.' It provides a clear diagnostic tree: if only one code is present, suspect the corresponding valve; if both are present, suspect the shared solenoid.
• A user on Ross-Tech forums with a 2013 S4 (same 3.0T engine) and a P2440 code detailed their diagnostic process, which involved testing the valve with a vacuum pump and cleaning out minor gunk, which temporarily restored the valve's 'clicking' sound upon actuation.
• A user on AudiWorld with a 2011 Q5 3.2L received a P2440 code and forum members immediately pointed to either a faulty valve or the more serious carbon buildup issue, highlighting the community's familiarity with this specific failure.

Mechanic-Grade Diagnostic Values

• Secondary Air Injection Pressure Sensor (G609) Voltage — expected: Approx. 2.9 VDC with engine off/SAI pump off. Rises to 3.0-3.5 VDC when the pump runs.. Failure: Voltage is stuck, does not change, or reads 0V or 5V, indicating a failed sensor or wiring issue.
• Wiring Harness Resistance — expected: Max. 1.5 Ω. Failure: A reading higher than 1.5 Ω indicates excessive resistance in the wire being tested.

Scan Tool Commands That Help

• VCDS (VAG-COM): Output Test (03) for Secondary Air — This function allows a technician to sequentially command the SAI pump relay (J299) and the vacuum solenoid (N112). It is used to verify that the components can be activated by the ECM and that the wiring is intact.
• VCDS (VAG-COM): Basic Settings - Group 077 — This initiates a complete SAI system functional test. The ECM runs the pump and checks for the expected pressure change via the G609 sensor. This can be used to confirm a fix or to see if the system passes its own self-test.

Wiring & Ground Locations

• J299 — In the underhood fuse/relay panel.. This is the relay for the Secondary Air Injection (AIR) Pump. While a failure here usually causes 'insufficient flow' codes, an intermittent or stuck relay could cause control issues.
• Fuse SB10 — In the underhood fuse panel.. This fuse is part of the power supply circuit for the Motronic Engine Control Module (ECM) which controls the SAI system.
• Earth Connection 131 — In the engine compartment wiring harness.. This is a primary ground connection for the engine harness. A poor ground here can cause a variety of intermittent electrical faults for engine sensors and actuators, including the SAI system.

Real Owner Repair Stories

• Ross-Tech Forums user (2013 Audi S4 (3.0T engine)) — Check Engine Light with P2440 after major engine-out service for an oil leak and carbon cleaning.
  ❌ Tried (didn't work) Replaced the N112 vacuum switching solenoid., Ran VCDS Basic Settings test for the SAI system, which would pass and fail intermittently.
  ✅ What actually fixed it The user removed the air pump hose from the combi valve and found some 'gunk' inside. After cleaning it out with compressed air, the valve began audibly 'clicking' again when tested with a vacuum pump, suggesting it was mechanically stuck from debris, not electrically or pneumatically failed.

OEM Part Supersession History

• 06E-131-101-E, 06E-131-101-J → 06E-131-101-K — Part revision by the manufacturer, likely for improved durability or material changes.

Model Year Variations Within This Range

• 2011-2012 (3.2L) vs 2013-2014 (3.0T): The 3.2L V6 FSI and 3.0T V6 TFSI are different engine families, though they share a similar V6 architecture and secondary air system design. While the P2440 code has the same meaning and common causes (combi valve, solenoid), the exact location of components and some part numbers may vary slightly. The issue of carbon buildup in the secondary air ports is common to both engines.