Vehicle: 2001 Volkswagen Passat GLX, 2.8L

Complaint: The customer says the vehicle will not start.

Cause: Confirmed the customer’s complaint and found the vehicle did not start. Connected a scan tool and found the following codes:

• 17978 – Engine Start Blocked by Immobilizer;
• 18034 – Powertrain Data Bus: Missing Message from TCU;
• 18044 – Powertrain Data Bus: Missing Message from Airbag Controller;
• 18056 – Powertrain Data Bus Failure; and
• 18057 – Powertrain Data Bus: Missing Message from ABS Controller.

Performed an inspection of the engine compartment and found no faults. Used a multi-meter to check for the presence of voltage and ground at the engine control module while cranking the engine, and found both were present. The result of these tests verified the engine control module was functional.

Attempted to access the transmission control module (TCM) located underneath the passenger-side carpet and found the carpet was damp. Inspected for signs of water intrusion and found the passenger-side cowl vent was plugged with debris. The plugged passenger-side cowl vent allowed water to seep into the vehicle and caused damage to the transmission control module.

Correction: Cleaned the ­passenger cowl vent, replaced the transmission control module, cleared codes and verified the vehicle operated properly. The customer’s concern didn’t return.

Courtesy of Mitchell 1’s SureTrack Real Fixes.