If DTCs 00545/00638 are stored on a 2003 Passat Sedan 4Motion, the problem may be caused by:

• Incorrect Engine Control Module (ECM) coding (codeable ECM only);
• Wiring harness and/or connections between the Transmission Control Module (TCM) and ECM;
• Malfunctioning ECM;
• Intermittent continuity in the engine harness.
• Poor engine compartment ground (GND).

Service Procedure:
If the vehicle exhibits this condition, use the table as a guide for repairs. Erase the DTC memory, road-test the vehicle and recheck for any stored DTCs.

Courtesy of ALLDATA.