2018 Volkswagen Passat

A major engineering and material design failure occurred involving internal fluid containment seals, resulting in a severe electrical safety hazard. Pressurized engine coolant breached an internal component seal and began migrating internally directly through the vehicle's engine wiring harness via capillary/siphoning action. The fluid used the sealed wiring loom as a literal pipeline, traveling inside the wire insulation to bypass all outer weather seals and completely flood the Engine Control Module (ECM) pin connectors. The vehicle's dealership service department documented extensive galvanic corrosion and shorting inside the primary vehicle computer pins due to this blue-green fluid pooling. Because the dealership has not yet completed the full repair, the exact originating component source of the leak (e.g., the engine coolant temperature sensor or the coolant expansion tank housing barrier) remains unconfirmed. However, the physical mechanism of the coolant migration through the sealed harness into the primary electrical architecture is fully verified. This defect presents a critical safety risk. The sudden flooding and short-circuiting of the Engine Control Module can cause an immediate and unexpected loss of engine propulsion, power steering assist, and electrical control while driving at highway speeds, creating an imminent risk of a high-speed collision.

The contact owns a 2018 Volkswagen Passat. The contact stated that while driving at an undisclosed speed, the infotainment screen failed to respond to touch commands, preventing the contact from viewing the GPS feature. The contact performed a hard reset on the vehicle, but the failure persisted. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 70,000.

The contact owns a 2018 Volkswagen Passat. The contact stated that while driving at an undisclosed speed, the vehicle stalled. There was no warning light illuminated. The vehicle was unable to restart and was towed to the dealer to be diagnosed. The vehicle was diagnosed with battery failure. The contact was informed that the battery needed to be replaced. The vehicle was repaired; however, the failure recurred. The vehicle was then towed to a different dealer; however, the vehicle was not diagnosed or repaired. The manufacturer was not made aware of the failure. The approximate failure mileage was 136,000.

I initially brought my vehicle in for service due to a strong gasoline odor and the vehicle failing to start. At that time, I was informed that no gasoline smell was detected and that the issue was instead a faulty starter, which I authorized for repair. Approximately two weeks later, my vehicle again would not start. I was then informed that the issue was a lower fuel injector, which required additional repairs. Just three days after that service, the vehicle once again failed to start, and I was told this time that the upper fuel injector was the cause. As a result of these events, I incurred a total of $3,946.96 in repair costs across two service visits and was forced to have my vehicle towed three separate times. Before the third visit, I was informed that I would need to pay an additional $1,500, on top of the nearly $4,000 I had already paid. I challenged the accuracy and consistency of the diagnoses at that point, and ultimately, the vehicle was repaired without charging me the additional $1,500. While I appreciate that the final repair was completed without further cost, I am deeply concerned about the pattern of repeated breakdowns, inconsistent diagnoses, and the financial burden placed on me as a customer. The original concern of a gasoline smell appears to have been valid from the outset, yet it took multiple failures, repairs, and significant expense before the underlying issue was resolved.

The contact owns a 2018 Volkswagen Passat. The contact stated that while driving approximately 40 MPH, the vehicle made an abnormal sound and failed to accelerate as intended. There was no warning light illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed with a wiring harness failure. The vehicle was repaired. The contact had received an unknown notice, which was related to the failure. The manufacturer was contacted for reimbursement, and a case was filed. The contact sent the requested documents to the manufacturer; however, the manufacturer failed to call back as the manufacturer had stated. The failure mileage was approximately 55,000.

Battery drains overnight. Started with a boost all dashboard warning lights on, vehicle runs fine all day with many starts and stops, battery dies again overnight. Diagnosed with a bad fuel pump control module that continues to run and does not shut off until all battery power is drained. Mechanic changed the fuel pump control module, cleared all fault codes, and vehicle fixed. I saw a Carfax report for an identical 2018, SEL Premium Passat to mine with the exact same issue of a bad fuel control module in that vehicle Carfax report and realized it was a much bigger issue. I am aware of a similar recall for vehicles up till 2016 model year, but this issue is wider for higher model years. Besides the other identical problem listed below in the Carfax report, I am aware of many other fuel pump control module problems reported to online VW forums and online. The identical Passat vehicle information is below: 2018 VOLKSWAGEN PASSAT 2.0T SEL PREMIUM VIN: [XXX] XXX SEDAN 4 DR 2L I4 F DOHC 16V GASOLINE FRONT WHEEL DRIVE 06/27/2025 69,955 mi Piazza Volkswagen Ardmore Ardmore, PennsylvaniaArdmore, PA Ardmore, XXX [XXX] 4.6 / 5.0 88 Verified Reviews 2,091 Vehicle serviced Maintenance inspection completed Fuel pump module replaced Vehicle washed/detailed URL for this vehicle Carfax report is below: [XXX] INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

The catalytic converter on my 2018 Volkswagen Passat failed and the vehicle has been at an authorized Volkswagen dealership since May 16, 2025. The dealership confirmed that the catalytic converter is defective and must be replaced, but the part has been on national backorder with no estimated delivery date for several months. The vehicle cannot be safely driven in its current condition and has been unavailable for all normal use. The issue has been confirmed by the dealership and the vehicle is available for inspection. There were warning lights related to emissions prior to the failure. Volkswagen has not been able to provide a timeline for repair, which has created an ongoing safety and reliability concern.