DTC P1471/17879 - EVAP Emission Control System LDP Circuit Short To B+

NOTE: DTC is set after engine start if output of Leak Detection Pump (LDP) is high for more than .2 seconds with pump not activated.

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.
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.
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 5). 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.
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.
Replace faulty PCM. Code new PCM and test drive vehicle. See PCM CODING in this article.