P2407 on 2020 Volkswagen Passat: EVAP Pump Circuit Fault Causes & Fixes

What's Unique About the 2020-2020 Volkswagen PASSAT

For the 2020 Passat and other MQB platform vehicles, this code points specifically to an electrical communication problem with the leak detection pump's internal sensor. Unlike other EVAP codes that suggest a physical leak (like a loose gas cap or cracked hose), P2407 is about the integrity of the signal from the pump back to the computer. Volkswagen has also issued a Technical Service Bulletin (TSB 01-23-03) indicating that the engine software on some vehicles is too sensitive and may erroneously store a P2407 fault. In these cases, a software update is the correct fix, not parts replacement. The NHTSA has also documented this code appearing on 2020 Passats, confirming its relevance to this specific model year. (Bulletin #VIN4APIN20200812, #VIN4APIN20200728, #VIN4APIN20200720)

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 is on.
• Inability to pass an emissions inspection because the EVAP monitor will not become 'ready'.
• A faint fuel smell may be noticeable near the rear of the vehicle.
• Reduced fuel efficiency in some cases.

Most Likely Causes

1. Faulty EVAP Leak Detection Pump (LDP) 🔴 High Probability The LDP is a mechanical and electrical component located in the rear passenger-side wheel well, exposed to road debris and moisture. The internal sensor or switch can wear out or fail, causing erratic signals.
   How to confirm: Using a capable OBD-II scanner (like VCDS for VW), command the LDP to activate and monitor the voltage or status of the LDP sense circuit. If the readings are erratic, drop out, or are otherwise unstable while the pump is activated, the pump is likely faulty. A visual inspection may reveal cracks or damage to the pump housing. A resistance test can also be performed.
   Typical fix: Replace the Leak Detection Pump assembly. This involves removing the rear passenger wheel and fender liner, disconnecting two hoses (one with a squeeze-style connector, one with a single tab) and the electrical plug, and unbolting the canister assembly to access the pump, which is typically held by three screws. 🎬 See this walkthrough for accessing and swapping the pump. A new hose clamp will be needed for one of the lines.
   Est. part cost: $150-$300
2. Damaged Wiring or Corroded Connector 🟡 Medium Probability The wiring harness to the LDP runs underneath the car and is susceptible to damage from road debris, moisture, and corrosion, especially at the connector pins.
   How to confirm: Visually inspect the entire wiring harness leading to the LDP for any signs of fraying, pinching, or breaks. Unplug the connector and check for green or white corrosion on the pins. Perform a continuity test on the sense circuit wire between the LDP connector and the ECM.
   Typical fix: Repair the damaged section of wire or clean/replace the electrical connector.
   Est. part cost: $5-$50
3. Outdated Engine Control Module (ECM) Software 🟡 Medium Probability Volkswagen/Audi released TSB 01-23-03 and 01-24-16, which state that overly sensitive OBD diagnostics in the ECM software can cause a P2407 code to be stored erroneously.
   How to confirm: A Volkswagen dealership or a qualified independent shop with access to VW's ODIS diagnostic system can check the vehicle's software version against the TSBs. If the software is outdated, the TSB applies.
   Typical fix: Update the Engine Control Module (ECM) software. This must be done by a dealer or a properly equipped shop. The TSB explicitly states not to replace components for this fault before performing the software update.
   Est. part cost: $0-$200 (May be covered under warranty)

Rare But Worth Checking

• Faulty Powertrain Control Module (PCM): This is very rare. Before condemning the PCM, all other possibilities, especially the LDP, its wiring, and the possibility of a required software update, must be exhaustively ruled out. A PCM fault would typically be accompanied by other trouble codes.

Diagnosis Steps

1. Read the code with an OBD-II scanner to confirm P2407 is present.
2. Check for applicable Technical Service Bulletins (TSBs). Specifically, reference VW TSB 01-23-03 or Audi TSB 01-24-16 to see if an ECM software update is the recommended first step. If so, have this performed before proceeding.
3. If no TSB applies or the software is up to date, locate the Leak Detection Pump (LDP). It is housed with the charcoal canister assembly in the rear passenger-side wheel well.
🎬 Watch: How to replace a faulty leak detection pump.
4. Visually inspect the LDP's electrical connector and wiring harness. Look for corrosion on the pins, loose connections, or damaged/chafed wires.
5. If the wiring appears intact, use a multimeter to check for proper voltage and ground at the LDP connector according to the vehicle's service manual. Test the LDP resistance across its pins.
6. Use an advanced scan tool (like VCDS) to perform an output test on the LDP, commanding it to activate. While activated, monitor the sense circuit's voltage or status. The signal should be stable; if it is intermittent, fluctuating, or erratic, the LDP is the primary suspect.
7. If the LDP and wiring are confirmed to be good, the final step would be to test the corresponding input circuit at the Powertrain Control Module (PCM), though this is rarely the cause.

Parts You'll Likely Need

• EVAP Leak Detection Pump (OEM #5Q0906253D (or superseding revisions like 5Q0906253E)) — This is the most common failure point for a P2407 code, as the internal sensor fails and sends an erratic signal.
  Trusted brands: Bosch, Genuine VW
  OEM price range: $200-$300
  Aftermarket price range: $150-$220

Related Codes That Often Appear With This One

• P0442 — P0442 indicates a small EVAP leak. It can sometimes appear with P2407 if the LDP's erratic signal causes the ECM to misinterpret the system's status, or if there is both a circuit fault and a small leak. VW TSB 01-23-03 specifically mentions that outdated software can cause both P2407 and P0442 to be stored. NHTSA TSBs for the 2020 Passat also list both codes as potential customer complaints. (Bulletin #VIN4APIN20200728, #VIN4APIN20200720)
• P2450 — This code relates to the EVAP System Switching Valve. A Reddit user with a VW GLI reported having both P2407 and P2450 codes intermittently, suggesting a potential relationship between the components in the EVAP system.

Technical Service Bulletins (TSBs) & Recalls

• VIN4APIN20200812: Notes customer complaints of MIL-on with P2407.
• VIN4APIN20200728: Notes customer complaints of MIL-on with P2407.
• VIN4APIN20200720: Notes customer complaints of MIL-on with P2407.
• VW TSB 01-23-03: States that current engine software may allow erroneous P2407 faults to be stored and advises an ECM software update as the fix before replacing parts.
• Audi TSB 01-24-16 (2071770/5): While for Audi models, this TSB also addresses P2407 caused by overly sensitive OBD diagnostics, recommending a software update. This indicates a platform-wide issue.

Platform-Specific Known Issues

• NHTSA Technical Service Bulletins for the 2020 Volkswagen Passat list customer complaints of the Malfunction Indicator Lamp (MIL) being on with code P2407 stored, confirming this is a known issue for this specific model. (Bulletin #VIN4APIN20200812, #VIN4APIN20200728, #VIN4APIN20200720)
• A specific VW TSB (01-23-03) addresses this code, noting that overly sensitive software can trigger the fault. The prescribed fix is an ECM software update, not component replacement.

Mechanic-Grade Diagnostic Values

• Leak Detection Pump (V144) Internal Resistance — expected: Pins 1 & 3: 640 to 720 Ω. Pins 2 & 3: 15 to 17 Ω.. Failure: Readings significantly outside these ranges indicate an internal failure of the pump's solenoid or sensor components.
• LDP Sense Circuit Voltage (Live Data) — expected: A stable voltage, typically between 4.5V and 5.0V, when the pump is commanded on by a scan tool.. Failure: Voltage that jumps around erratically, or drops to 0V while the pump is activated, points to an intermittent wiring or connector issue.

Scan Tool Commands That Help

• VCDS (VAG-COM): Engine -> Output Tests -> Leak Detection Pump (V144) — To manually activate the LDP and listen for its operation (clicking) while observing live data for the sense circuit to check for intermittent electrical faults.
• VCDS (VAG-COM): Engine -> Basic Settings -> Group 070 (Fuel Tank Leak Test) — To run the complete, automated EVAP system self-test. The results will display as 'System OK' or 'System Not OK', providing a comprehensive check after a repair.

Wiring & Ground Locations

• Rear Chassis Ground Stud — Typically located behind the passenger side trunk/boot trim panels. Look for a threaded stud welded to the chassis with multiple brown wires attached to it via ring terminals.. The Leak Detection Pump, located in the passenger rear wheel well, requires a solid ground connection to function. A loose or corroded ground at this common point can cause intermittent and erratic circuit behavior, leading to a P2407 code.

OEM Part Supersession History

• 5Q0906253A, 5Q0906253B, 5Q0906253C → 5Q0906253D (and later revisions like 5Q0906253E) — Standard part evolution for improved reliability or manufacturing changes.
  Heads up: Revisions are generally backwards compatible. Always use the latest available part number when replacing.