2018 Audi A4 Complaints

A vehicle diagnostic scan dated 04/15/2026 at approximately 88,502 miles showed a stored transmission electronics fault: P084100, described as “Transmission fluid pressure sensor/switch A range/performance,” with status listed as passive/sporadic. This indicates a transmission / powertrain control concern involving the transmission fluid pressure sensor, transmission electronics, wiring, control logic, pressure monitoring, or related powertrain components. The vehicle also has prior transmission/powertrain history, including a March 2023 transmission-pan-gasket concern documented in service records, so this later transmission electronics fault is being reported in that broader powertrain context. This is being reported as a safety concern because a transmission fluid pressure sensor or transmission-control fault can affect shifting, drivability, delayed engagement, slipping, harsh shifting, limp mode, reduced power, drivetrain damage, or loss of propulsion while driving. Even if the...

A vehicle diagnostic scan dated 04/15/2026 showed electrical communication faults involving vehicle control modules. The scan showed U014100, described as “Lost Communication With Body Control Module ‘A’,” with status listed as passive/sporadic. The scan also showed U112100, described as “Data bus message missing,” with status listed as active/static. This is being reported as a safety concern because body-control module, gateway, and data-bus communication faults can affect vehicle electrical functions, warning systems, access/locking systems, lighting or body-control functions, driver information, and other vehicle systems that rely on module communication. The concern is especially important because the vehicle has had multiple intermittent electrical/body-control symptoms, including fuel-door/tank-flap electrical faults and other reported intermittent vehicle electrical concerns. No crash, fire, injury, or fatality occurred. The vehicle/component is available for inspection, and...

An Audi dealer installed 245/40R18 93H tires on this 2018 Audi A4, while the vehicle placard/specification requires 245/40R18 97H. The lower load index reduces capacity from 1,609 lb per tire to 1,433 lb per tire, approximately 704 lb total across four tires. This creates a safety risk because load-rated tires affect vehicle stability, heat buildup, braking, steering/cornering, suspension loading, and tire failure/blowout risk. After discovering the mismatch, the concern was reported to the dealer and Audi, but the dealer stated the 93H tires were acceptable rather than providing a safety-based correction. No crash, fire, injury, or fatality occurred. This complaint is being submitted because the vehicle may have been operated with under-rated tires and because the issue can affect handling, braking, tire durability, suspension/wheel components, and safe vehicle control. Tire/repair-order records, door-jamb placard evidence, load-index comparison evidence, and dealer communications ar...

The rear-view camera intermittently fails to engage when the vehicle is shifted into reverse. When the camera does display, the image sometimes shows horizontal glitch lines/artifacts. This affects backing visibility and parking safety and creates a risk of collision with pedestrians, objects, vehicles, or property. The concern was reported to Audi service along with other electrical/driver-assistance symptoms, suggesting a possible camera, wiring, module, signal-processing, or broader electrical fault. No crash, fire, injury, or fatality occurred. This complaint is being submitted because the rear camera/reverse display is a backing-safety system and the intermittent failure is unpredictable. The vehicle/component is available for inspection, and photo/video evidence and service communications are available.

The vehicle displayed a low coolant warning and the coolant reservoir was low. Audi dealer service records dated on or about 02/14/2025 document the concern as: “client states low coolant warning was on, coolant reservoir is low, diagnose and advise.” The dealer performed coolant-related work involving the thermostat gasket / coolant hoses or connections to the coolant reservoir, ran the vehicle to operating temperature, and rechecked. The concern is being reported because the coolant loss/refill issue continued or remained unresolved afterward. The exact source of coolant loss is unknown, but it may involve the water pump, thermostat, coolant reservoir, coolant hoses/pipes, pressure loss, internal coolant leak, or coolant loss that evaporates before leaving visible residue. This is a safety concern because coolant loss can lead to overheating, warning messages, limp mode, loss of propulsion, engine damage, steam/smoke, or stall risk while driving. No crash, fire, injury, or fatality...