Case Study: VW Passat dual clutch transmission does not shift after a fluid change, DTC P1814

Aug. 11, 2022

This Passat, with an 02E automatically shifted manual transmission was in the shop for a routine transmission fluid drain and fill. After the fluid change, however, the transmission would not shift on its own in “Auto” mode.

Richard Diegle

Related To: ALLDATA

Vehicle: 2018 Volkswagen Passat Sedan (A33), V6-3.6L (CDVB), Automatically Shifted Manual Transmission/Transaxle

Mileage: 162,556

Problem: This Passat, with an 02E automatically shifted manual transmission was in the shop for a routine transmission fluid drain and fill. After the fluid change, however, the transmission would not shift on its own in “Auto” mode, and the malfunction indicator light (MIL) was illuminated in the instrument cluster.

Case Details: The technician retrieved the diagnostic trouble code (DTC) P1814 – Transmission Oil Pressure Control Valve 1, Open or Short to Ground. The DTC was not present when the vehicle came in for service. It was a good time to call an ALLDATA Tech-Assist consultant.

The consultant advised that, after a transmission fluid change, it’s important to drive the vehicle through all the gears in “Manual” mode for 30 to 45 minutes. Afterwards, clear the DTCs, then put the transaxle in “Auto” mode. it should operate normally.

NOTE: The pressure control valves must be primed or purged of air after a transmission fluid drain and refill.

Confirmed Repair: The technician drove the Passat with the transmission in “Manual” mode as suggested. After driving for 45 minutes, he cleared DTCs and put the transmission in “Auto” mode. It operated as designed, and the MIL stayed off. Fixed!

Reprinted with permission from ALLDATA.

About the Author

Richard Diegle | Senior Automotive Editor for ALLDATA

Rich Diegle has been in the automotive industry since 1978. After graduating from a local community college, he began working at a Nissan dealership as a used car technician. Since then, he’s worked as a Nissan and ASE master automotive technician, shop owner, marketing copywriter, automotive editor, public relations manager, instructor, ALLDATA Tech-Assist team manager, and a senior automotive editor.