Which parts fail
Components named in complaints (battery, alternator, wiring, ignition, instrument cluster, infotainment).
Mileage when the problem started
Owner reports
Selected complaints filed with NHTSA by 2018 Audi Q5 owners, lightly cleaned up (personal details are redacted by NHTSA).
The contact owns a 2018 Audi Q5. The contact stated while driving 30 MPH, several unknown warning lights were illuminated. Additionally, the turn signals were inoperable. The contact pulled over and noticed that the rear lights including brake lights and turn signals were not operational. The vehicle was taken to the dealer where the cause was diagnosed as a sunroof drain line leakage that caused electrical damage due to water build-up, which damaged the control module. The contact stated that the drain lines needed to be unclogged and the control module needed to be replaced. The contact stated that the vehicle was at the dealer awaiting the repairs. The contact was concerned that the Owner's Manual did not guide sunroof maintenance to prevent the failure. The contact opened the rear hatch and found water accumulation under the mat. The manufacturer was not made aware of the failure. …
The contact owns a 2018 Audi Q5. The contact stated that while driving 35-40 MPH and accelerating, the vehicle lost motive power. The contact pulled to the side of the road, and the vehicle was able to restart. Several unknown warning lights were illuminated. The vehicle was taken to an independent mechanic, where it was diagnosed that the body control module(BCM) was floating in water. The vehicle was not repaired. The local dealer was not contacted. The manufacturer was contacted and informed the contact that the vehicle was previously repaired under NHTSA Campaign Number: 21V947000 (Electrical System, Structure), and the additional repairs were at the contact's expense. The contact stated that the recall remedy was inadequate for the failure. The failure mileage was approximately 58,000.
The contact owns a 2018 Audi Q5. The contact stated that while pulling into a business at an undisclosed speed, there was an unknown warning light illuminated, and the message "Left and Right Rear Signal and Center Rear Brake Light Malfunction" was displayed. Additionally, the contact stated that the key warning light and engine malfunction warning lights were illuminated. The vehicle was taken to a dealer where it was determined that there was water intrusion into the rear cargo area of the vehicle, due to a clogged drain. The contact was informed that the drain tube needed to be cleaned, the module needed to be replaced, and the vehicle needed to be rewired. The vehicle was not repaired. The manufacturer was notified of the failure. The failure mileage was approximately 83,000.
The contact owns a 2018 Audi Q5. The contact stated that while starting the vehicle in a severe rainstorm, the vehicle experienced electrical failures, which included the head lights flashing and the horn activating before the vehicle suddenly became inoperable. The vehicle was towed to the local dealer who discovered that rainwater had leaked into the rear of the vehicle and the electrical components were submerged in water causing an electrical failure. The vehicle was not yet repaired. The manufacturer was notified of the failure, but no assistance was offered. The contact stated that the vehicle was previously serviced under the NHTSA Campaign Number: 21V947000 (Electrical System, Structure). The failure mileage was 53,000.
The contact owns a 2018 Audi Q5. The contact stated that while driving his vehicle, a start/stop malfunction warning message appeared on the display screen. Once the contact made it to his destination, the vehicle failed to turn off after repeatedly pushing the start/stop button. The next day, the failure persisted and the vehicle was taken to a dealer where a diagnostic was performed. The diagnostic showed that water had traveled from the sun roof drains into the rear left panel and into the vehicle's wiring module. The manufacturer was notified of the failure and informed him that there were no recalls on the vehicle. The vehicle had yet to be repaired. The failure mileage was approximately 72,000.
The contact owns a 2018 Audi Q5. The contact stated the vehicle was parked during a rainstorm and the contact attempted to start the vehicle, but the vehicle failed to start. The vehicle was taken to the dealer who performed a diagnostic test and stated that water entered the vehicle through a fractured seal causing the electrical wiring to get wet. The vehicle was not repaired due to the cost. The contact referenced NHTSA Campaign Number: 21V947000 (Electrical System, Structure) as a possible solution to the failure however, the VIN was not included in the recall. The manufacturer was notified of the failure. The failure mileage was approximately 190,000.
The contact owns a 2018 Audi Q5. The contact stated that vehicle failed to start. The contact stated that while replacing the battery, he observed condensation near the wiring. The vehicle was taken to an independent mechanic where the vehicle was hoisted up and there was condensation draining from the driver's side of the vehicle. The vehicle was not diagnosed or repaired. The manufacturer was not notified of the failure. The failure mileage was approximately 48,000.
There is a module under the back seat called the J533 that I am told got wet. This completely shut down the entire car as my wife and child were driving down the highway. We were very disheartened to find out that this is an out of pocket expense for a common thing to happen in the back of an SUV. After searching online, I came across this link, which is an identical account: https://www.audiworld.com/forums/q5-sq5-mkii-discussion-218/control-module-ruined-moisture-corrosion-3001605/ I'll highlight one area in this link thread, as it most strongly relates to your questions above: "Audi (VOA) faces considerable legal exposure for any injury caused by a liquid finding its way into a component that poses such a high risk of harm if the module fails. . which evidently it does via corrosion following moisture intrusion of some sort. …
In early July, 2023 various warning and fault lights began to show on the dashboard: engine start system, brake lights, start/stop system, and others - indicating malfunctions with systems important to safety. Also, the car alarm system sounded without cause and key pods would not lock/unlock the doors electronically. These warning lights proliferated over several days. We took our car into our local Audi dealership. They diagnosed the problem as follows: "Performed GFF and found code for 3393 comfort system control module replacement. Control module faulty due to control unit being submerged in water and fried the control unit. Water leak due to rear drains clogged causing the water to overflow. …
Rear Sunroof drain leak into major electronic components. 2018 Q5 with 61k miles after heavy rain started receiving all kind all errors including lights and ignition. Upon inspection Audi service has stated that HVAC control module has shorten (the area with the module in the left rear portion of the trunk filled with water), quoting repair of the module and insisting to replace sunroof drain hoses for total of $5k. Insurance has agreed to cover module replacement due to the flood of approx. $2,5k, however drain hoses and deducible with another $2,5k would not be covered and is on me. Mechanic in the Audi service several times noted that that this is common issue with Q5 and Q7s., I am so frustrated and do not understand how come the Audi car the owner shall be responsible for any cost of such if it is unclear: 1. …
Electrical complaints in other Q5 years
Frequently asked questions
How common are electrical problems on the 2018 Audi Q5?
NHTSA has 74 complaints about the electrical system of the 2018 Audi Q5, 36% of the model year's 208 complaints. The component named most often is ignition (1 mentions).
Is there a recall for 2018 Audi Q5 electrical problems?
No. NHTSA lists no electrical system recall for the 2018 Audi Q5, though it has 6 recalls for other components. If the problem is widespread, a repair may still be covered by an extended warranty or a manufacturer service bulletin — ask a dealer.
At what mileage do 2018 Audi Q5 electrical problems start?
Half of the complaints with a recorded mileage happened before about 32,000 miles, and 41% before 25,000 miles.
Source: U.S. National Highway Traffic Safety Administration (NHTSA) — owner complaints through October 20, 2026, recalls and defect investigations; fuel economy from the EPA. Complaints are unverified reports and are not proof of a defect. How we rate model years.