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DTC codes / Volkswagen codes / P1475

P1475 · VolkswagenEVAP Emission Control System LDP Malfunction Signal Circuit Open

P1475 on Volkswagen vehicles means the engine control module has detected an open circuit in the signal wire for the Leak Detection Pump (LDP), which is part of the EVAP emission control system. The LDP is a small pump that pressurizes the fuel tank and lines so the computer can check for leaks, and this code sets when the signal circuit from the pump back to the module is broken or disconnected.

SystemPowertrain
Code typeVolkswagen specific
SeverityLow
Fix difficultyIntermediate
AreaAuxiliary emission controls

Symptoms you may notice

  • The check engine light is illuminated, often with no other symptoms.
  • A slight fuel odor may be present around the rear of the vehicle if the EVAP system is not sealing properly.
  • The engine may run normally with no noticeable performance issues.
  • In some cases, a faint clicking or humming from the rear of the car may be missing because the LDP is not being commanded on.
  • Fuel economy may drop slightly if the EVAP system cannot complete its self-test and the engine management strategy changes.

Common causes, most likely first

  1. Broken or disconnected signal wire between the LDP and the engine control module.
  2. Corroded or damaged electrical connector at the LDP or at the module.
  3. Failed LDP solenoid or internal pump circuit causing an open signal path.
  4. Rodent damage to the wiring harness near the fuel tank or under the rear seat.
  5. Water intrusion into the connector or harness causing corrosion and an open circuit.
  6. Faulty engine control module driver for the LDP signal circuit, though this is rare.

How to diagnose and fix it

  1. Connect a scan tool and verify P1475 is the only EVAP-related code, then clear it and test-drive to see if it returns.
  2. Visually inspect the LDP and its electrical connector for corrosion, loose pins, or damage.
  3. Check the signal wire from the LDP connector to the engine control module for continuity and resistance using a multimeter.
  4. Inspect the wiring harness along the route from the LDP to the module for chafing, rodent damage, or pinched wires.
  5. Test the LDP itself by applying power and ground to confirm the pump runs and the signal circuit behaves correctly.
  6. If the wiring and LDP are good, check the engine control module connector and, if necessary, test the module driver circuit.
  7. Repair or replace the faulty wiring, connector, or LDP as needed, then clear codes and verify the repair with a complete EVAP monitor drive cycle.

What a P1475 really tells you

  • An open signal circuit does not always mean the LDP is bad; a simple broken wire or corroded pin is a far more common cause on older Volkswagens.
  • The LDP is only commanded on during specific conditions, so a faulty signal circuit may not affect driveability at all and the car can feel perfectly normal.
  • Rodents chewing on the EVAP harness near the fuel tank is a frequent hidden cause, especially on cars parked outdoors for long periods.
  • A generic OBD-II scan tool may not read manufacturer-specific codes like P1475 accurately, so use a tool that supports Volkswagen protocols.
  • Do not replace the LDP before checking the signal wire continuity, because a new pump will not fix a broken circuit.

Can I keep driving with P1475?

You can usually continue driving with P1475 because it does not affect engine performance or safety, but the vehicle will not pass an emissions inspection until the fault is repaired. Avoid ignoring the light for long periods, as a persistent EVAP fault can mask other issues and may lead to a failed smog test.

Tools that help

Tools we recommend are in the Auto Veteran shop on Amazon. As an Amazon Associate we earn from qualifying purchases.

Guidance is general and written for Volkswagen vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.

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