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 2006 Volvo S40 owners, lightly cleaned up (personal details are redacted by NHTSA).
Prior to this incident, my car idled down and pressing the gas did not prevent it from coming to a complete stop. The check engine light illuminated and all of the lights came on to include, warning lights, airbag, stability control, and others including ABS. Fortunately we had just exited the highway to purchase fuel and was in no immediate danger. Because of the vehicles age it was recommended we have the starter, oxygen sensor, spark plugs, 1 coil pack, and battery replaced; and the fuses, fuel pump, fuel filter, alternator and wiring examined, but they did not need to be replaced. After reading other complaints about the electrical problems of this vehicle, I am seriously wondering if this car is safe. …
We had been experiencing rain showers on the way to work the Volvo twice had all the lights on the dash board light up but the car did not stall. I was afraid the air bag might deploy. As soon as I got home I had my husband check to see if he could locate the problem. He found was that the carpet was soaked on the drivers side .and the. Wiring running under the carpet was also wet. We have not moved the car and are trying to dry everything. It has also continued to rain off and on. My husband has found some information on the internet which could be related to this problem and will try to see if this might be the solution to our problem.
Vehicle passenger rear floor flooding continuously. One day the windshield wipers wouldn't turn off and none of the interior electrical equipment would work, no power windows or locks. Drove to Volvo, they stated clogged sunroof drain and that floormat had affected the ECM under the steering column. They cleared drain and cleaned floor for $1K. A year later the front drivers seat floor started flooding. Experienced many electrical problems since. Including an instance entering the highway when the power steering seemed to go out and the car stalled. The screen told me to pull over safely. Very scary.
Tl* the contact owns a 2006 Volvo S40. The contact stated that while driving at approximately 40 MPH, the vehicle stalled and failed to restart. The vehicle was towed to an independent mechanic, who diagnosed that the sun roof drainage system was clogged and water entered into the vehicle which caused damage to the electrical system. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 65,000.
Water leaked into my vehicle through the sunroof, destroyed the computer and air airbag system. The carpets are soaked with standing water sitting in the body of the front passenger side of the vehicle. I took my vehicle to the dealership and was told the sunroof drainage tubes where clogged. I was then quoted a price for repairs which totaled in excess of $2000.00.
While driving down the road at approximately 50 MPH I noticed my dim ( driver information module) had completely stopped working. I was unable to read my speedometer, RPM, fuel level, and engine temperature while the car was still running . After researching this online, it appears that this seems to be a common problem.
A design flaw caused flooding within the cabin of this vehicle. The sunroof drainage system is faulty and over time leaks water into the floor pan of the car, sometimes enough where flooding occurs. My car flooded a few months back so badly up to 10 gallons of water was vacuumed out. The flooding caused damage to the electrical harness/connections under the driver's/passenger's seat. Currently the check engine light is on, the passenger seat air bag is deactivated and it is unsafe to sit in the passenger seat as the air bag could malfunction at any time, all due to this flooding and the root cause being the faulty drainage system that runs from the sunroof through the dash out of the bottom of the car. There is a class action law suit, no. …
2006 Volvo S40, FWD t5: my wife was driving on the interstate around midnight going approx. 75-80 MPH when all of a sudden her car shut off. When I say shut off I mean the headlights, dome lights, engine....anything that was electrical completely shut off. This would include the steering wheel locking up. So imagine driving in the middle of the night at 80 MPH with traffic around you and you're lights going out, steering wheel locking and having no way to control the vehicle. To me this sounds like a 80 MPH invisible torpedo that could have killed a few people including my wife. I had the vehicle towed to the nearest dealership which was a Ford dealership and the next morning they diagnosed it as a dead battery, which they were correct. Now I'm no rocket surgeon by any means but to me this sounds like a flaw in the safety dept. Somewhere. …
At least 5 times I have had the car in the Volvo dealership. The car without warning, powers down to 50%, the windshield wipers start up, all the gauges drop to zero position and ABS brake malfunction lights light up. If you pull over and stop, the car shuts down and you can not pull out the key. If I wait 15 minutes, the key can be turned off and you can restart the car. While the check engine light stays on, everything else is normal till the next time. It had done this 6 times in the last 6 months. Dealer can not figure it out other them a electrical malfunction from somewhere in the computer. If it happens going up a grade or hill, the power down slows the car in which is is sometimes impossible to power up over the hill. Every time we take it to the dealer, it then runs with no problem, but lasts 2 or 3 weeks before acting up again. …
1. Severe summer thunderstorms and rain. 2. Drove approximately 1 mile and right blinker stayed solid green after turning. Drove about a mile further onto highway entrance ramp and car indicator lights flashed ABS brake failure and air bag failure, then all car instruments (gas gauge, speedometer, tachometer, etc) failed for about five minutes. Instruments came back on but ABS brake and air bag failure continued to flash for about 1 more minute. Drove directly to dealership. 3. Service department took the car right in and applied grease to the harness connector which should alleviate problems as they are known to get wet and corrode. Please note this is a 2006 model as I have read on the website that the 2004 model has the exact same problem. Additionally, driver side door locks and power windows intermittently inoperable leading up to this failure. …
Electrical complaints in other S40 years
Frequently asked questions
How common are electrical problems on the 2006 Volvo S40?
NHTSA has 24 complaints about the electrical system of the 2006 Volvo S40, 41% of the model year's 58 complaints. The component named most often is instrument cluster/panel (1 mentions).
Is there a recall for 2006 Volvo S40 electrical problems?
No. NHTSA lists no electrical system recall for the 2006 Volvo S40, though it has 3 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 2006 Volvo S40 electrical problems start?
Half of the complaints with a recorded mileage happened before about 75,000 miles, and 10% 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.