2018 Audi A4 problems & reliability
44 owner complaints filed with NHTSA for the 2018 Audi A4, alongside 1 safety recall campaign. Last verified Sep 21, 2026. Complaints are unverified reports submitted by owners to the federal Office of Defects Investigation.
Each complaint is counted once (by NHTSA case number), even when it names several components.
Federal crash records (FARS 2020–2023): 2018 Audi A4 vehicles were involved in 12 fatal crashes with 4 occupant deaths. Involvement counts are not adjusted for how many are on the road and do not imply fault or a vehicle defect.
Most reported problems
| Component | Complaints | Share |
|---|---|---|
| Unknown / Other | 18 | 41% |
| Electrical System → | 17 | 39% |
| Fuel/propulsion System | 6 | 14% |
| Structure | 6 | 14% |
| Engine | 5 | 11% |
| Power Train | 5 | 11% |
| Air Bags | 4 | 9% |
| Forward Collision Avoidance | 4 | 9% |
| Service Brakes | 4 | 9% |
| Back Over Prevention | 2 | 5% |
Component groups as classified by NHTSA. A complaint can name more than one component, so shares may sum to more than 100%.
All 17 reported components →Common symptoms owners describe
Keyword analysis of complaint narratives; one complaint can describe several symptoms.
Complaints by incident year
What owners report
“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…”
Power Train · filed Jul 2, 2026
“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,”…”
Unknown / Other · filed Jul 2, 2026
“The vehicle has a recurring interior rattle / loose-trim concern involving interior panels, trim, speaker/subwoofer area, rear shelf, dashboard area, or related mounting components. The noise is not merely a comfort concern if it is caused by a loose component, fastener, grille, panel, or speaker housing that may…”
Unknown / Other · filed Jul 1, 2026
Verbatim excerpts from complaints filed with NHTSA. Reports are not independently verified.
Technical service bulletins
764 manufacturer communications (TSBs, service campaigns, warranty extensions) are on file with NHTSA for the 2018 Audi A4. The 10 most recent:
This bulletin provides information when the horn sound quality is poor.
TSB_2074436_3 · Service Bulletin/Repair Instructions · issued Aug 26, 2026
This bulletin provides information for all models regarding brake sounds.
TSB_2069904_3 · Service Bulletin/Repair Instructions · issued Aug 21, 2026
This bulletin provides information on the zirconium insercts in the brake piston (ceramic brakes only).
TSB_2069078_4 · Service Bulletin/Repair Instructions · issued Aug 21, 2026
This TSB describes a corrosion issue due to outside influence and the prohibition of warranty in these cases.
TSB_2068999_4 · Service Bulletin/Repair Instructions · issued Aug 21, 2026
This bulletin provides information when there is corrosion on the friction survace of steel brake discs.
TSB_2067132_4 · Service Bulletin/Repair Instructions · issued Aug 21, 2026
This bulletin provides service infomraiton regardin gthe identifaction of noises with dynamic steering.
TSB_2063546_5 · Service Bulletin/Repair Instructions · issued Aug 21, 2026
This bulletin provides service information when thre are engine noises in the vehicle interior.
TSB_2063528_5 · Service Bulletin/Repair Instructions · issued Aug 21, 2026
This bulletin provides information about leather care and seat repair.
TSB_2076945_2 · Service Bulletin/Repair Instructions · issued Aug 20, 2026
This bulletin provides information when there is a paint issue on alloy wheels.
TSB_2079732_2 · Service Bulletin/Repair Instructions · issued Aug 11, 2026
This bulletin provides information about the general approach for brake vibration concerns.
TSB_2075120_3 · Service Bulletin/Repair Instructions · issued Aug 11, 2026
TSBs are repair guidance manufacturers send to dealers — they are not recalls and repairs are not automatically free. Full documents are available on NHTSA’s site.
Safety recalls
The 2018 Audi A4 has 1 NHTSA recall campaign — recall repairs are free at franchised dealers regardless of the vehicle’s age.
Check whether your specific vehicle is affected
Recall campaigns often cover only certain VIN ranges. Enter your VIN on the official NHTSA site to confirm whether your vehicle is included and whether the repair is still open.
Check VIN on NHTSA →Buying a used 2018 Audi A4?
- · Decode the seller’s VIN with our free VIN decoder to confirm the exact year, engine and trim.
- · Check for unrepaired recalls by VIN on NHTSA’s official lookup — recall repairs are free.