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DTC P1475/17883 - EVAP Emission Control System LDP Malfunction/Signal Circuit Open

NOTE: DTC is set after engine start if output of Leak Detection Pump (LDP) is high for more than .2 seconds with pump activated.
  1. Inspect EVAP Leak Detection Pump (LDP) connector for looseness and/or corrosion. EVAP LDP is located in right rear wheelhousing behind liner. Repair EVAP LDP connector as necessary. If EVAP LDP connector was not repaired, go to next step. If EVAP LDP connector was repaired, erase DTC memory and test drive vehicle.
  2. EVAP cansiter purge valve may be sticking in closed position. Disconnect EVAP canister purge valve electrical connector. EVAP canister purge regulator valve is located on passenger side fender well in engine compartment. Using DVOM, check EVAP canister purge valve resistance. Measure resistance across EVAP canister purge valve terminals. Resistance should be 20-28 ohms. If resistance is within specification, go to next step. If resistance is not with specification, replace EVAP canister purge valve. Erase DTC memory and test drive vehicle.
  3. With ignition on, connect VAG 1527B voltage tester between EVAP canister purge valve harness connector terminal No. 1 and ground. Voltage tester should light up. If voltage tester lights up, go to next step. If voltage tester does not light up, check fuse for EVAP canister purge valve. If fuse is okay, go to next step. If fuse was replaced, erase DTC memory and test drive vehicle.
  4. Using a DVOM, check wiring between EVAP canister purge valve harness connector terminal No. 1 and fuse. See WIRING DIAGRAMS  section. If wiring is okay, check fuel pump relay and relay triggering. See SYSTEM/COMPONENT TESTS article. Go to next step.
  5. Connect VAG 1527B voltage tester between EVAP canister purge valve harness connector terminals. Using VAG 1551 scan tool, use OUTPUT DIAGNOSTIC TEST mode, function 03 to trigger EVAP canister purge valve. Voltage tester should flash. If voltage tester does not flash or lights up continuously, go to next step. If voltage tester flashes, ensure EVAP canister purge valve is not mechanically binding. Replace as necessary. Erase DTC memory and test drive vehicle.
  6. Turn ignition off. Disconnect Powertrain Control Module (PCM) connectors. Connect VAG 1598/19 test box to PCM wiring harness. Terminal assignments of test box are identical to PCM connectors "A", "B", "C", "D" and "E".
  7. Using DVOM, check resistance between EVAP canister purge valve harness connector terminal No. 2 and test box socket E12. Maximum resistance is one ohm. If resistance is within specification, go to next step. If resistance is not within specification, repair open or short circuit. Erase DTC memory and test drive vehicle. If an open or short circuit cannot be located, replace faulty PCM. Code new PCM and test drive vehicle. See PCM CODING  in this article.
  8. Disconnect EVAP LDP electrical connector. EVAP LDP is located in right rear wheelhousing behind liner. Using DVOM, check resistance between EVAP LDP terminals No. 1 and 3. Resistance should be 640-720 ohms. Using DVOM, check resistance between EVAP LDP terminals No. 2 and 3. See WIRING DIAGRAMS  section. Resistance should be 17.5-27.5 ohms. If resistance is within specification, go to next step. If resistance is not with specification, replace EVAP LDP. Erase DTC memory and test drive vehicle.
  9. With EVAP LDP electrical connector disconnected, start engine and let it idle. Connect VAG 1527B voltage tester between EVAP LDP harness connector terminal No. 3 and ground. Voltage tester should light up. If voltage tester lights up, go to step 11). If voltage tester does not light up, check fuse for EVAP LDP. If fuse is okay, go to next step. If fuse was replaced, erase DTC memory and test drive vehicle.
  10. Using a DVOM, check wiring between EVAP LDP harness connector terminal No. 3 and fuse. See WIRING DIAGRAMS  section. If wiring is okay, go to next step.
  11. Replace faulty PCM. Code new PCM and test drive vehicle. See PCM CODING  in this article.
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