2004 BMW 5 Series Problems

What owners report

Owners of this model year most often write about the passenger-side airbag and seat occupancy detection system: a restraint warning appears, and dealers frequently tell them their VIN is not covered by the related campaign. A second recurring theme is the heated seats, where complaints describe overheating and burns to the seat cushion. Electrical and lighting faults, an active-steering warning and low-speed transmission surging also appear across the sample, usually from roughly 40,000 miles upward.

1. 1
   Air bags

   Passenger airbag/restraint warning light (seat mat sensor)

   • 24 complaints (38%)
   • median 80,000 mi at 7.0 yrs old (22 state mileage)
   • 1 mention a crash, fire or injury
   • filed 2004–2019

   The passenger airbag light, the airbag warning lamp or an iDrive message reading "passenger restraint system malfunction" comes on and often stays on. Owners say there was no prior accident and the car drives normally, but the warning indicates the front passenger airbag may not deploy. Many report being told by the dealer that their VIN was outside the range of the frontal airbag campaign, and that seat occupancy mat or sensor replacement would be at their own cost, with quoted figures from about $1,000 upward. Some describe the warning returning after a mat was replaced. Reported from about 25,000 to 175,000 miles, most often in the 45,000-90,000 mile range, and frequently with no triggering event.

   Recall 08V3840005 related service bulletins

   What to check: With the ignition on and the passenger seat empty, confirm the airbag and restraint lamps go out after the bulb check and that no iDrive warning is stored. Ask whether the occupancy mat campaign was performed on this VIN and get the answer in writing.

   2 excerpts from owner complaints in NHTSA records

   “Passenger seat/airbag warning malfunction. This warning has been on since I purchased vehicle. It is obviously the common seat mat sensor failure. And it would appear that either my VIN isn't on the previous recall or it has expired for my year and model. But my wife sits in that seat and if we have an accident and her airbags do not deploy whose fault will that be?”

   NHTSA complaint #11130543, filed 2018-09, 175,000 miles

   “Passenger restraint malfunction illuminated on the dash. It indicates that the seat belt lock and/or airbags may not work in an event of an accident. When I called Bmw, they told me that my car is not covered under this recall and it will depend on my local dealership if I will have to pay for the repair.”

   NHTSA complaint #10255774, filed 2009-01, 85,000 miles
2. 2
   Seats

   Heated seat overheating and burns

   • 9 complaints (14%)
   • median 63,000 mi at 7.2 yrs old (8 state mileage, few)
   • 8 mention a crash, fire or injury
   • filed 2004–2018

   With the seat heater switched on, owners describe a burning smell, smoke and in some cases a scorched or burned hole in the leather, with a few reporting minor burns. Several say the heat came through the side bolster area, and some had to switch the heater off to stop it. Owners report that the dealer or manufacturer declined assistance or said the vehicle was not included in the seat heater campaign, and some simply stopped using the heater. Reported from very low mileage (as little as about 8,000-16,000 miles) up to around 147,000 miles, typically while the heater is switched on during a drive.

   Recall 04V575000

   What to check: Test the seat heaters briefly on both front seats from a cold start and look for discoloration, small holes or a hot spot in the leather and foam; ask whether the seat heating mats were ever replaced.

   2 excerpts from owner complaints in NHTSA records

   “Seat-warmer overheated, burning holes through the leather driver's seat, causing minor skin burns before terminating use of unit. Over the past two months, I had noticed a burning odor in the car periodically, but neither I nor my mechanic had been able to determine the source of the odor. On 1/27/12, I felt the extreme heat in my seat while driving, and found two charred holes in the leather seat. …”

   NHTSA complaint #10445684, filed 2012-01, 124,631 miles

   “About 3 weeks ago we noticed in the front passenger seat a mark that looks like a burnt - we thought that it was just a mark or somebody put a hot bottle o cup on the seat - but this morning we turn the heating in both seat to warm up a little bit then smell and smoke start to come out the burnt mark. We turned it off both sides and open the window - now our conclusion is the heating element caused that burn in the seat.”

   NHTSA complaint #11062870, filed 2018-01, 147,000 miles
3. 3
   Electrical system

   Electrical faults: battery drain, iDrive dropouts, warning

   • 10 complaints (16%)
   • median 88,000 mi at 7.1 yrs old (9 state mileage, few)
   • filed 2005–2017

   Complaints describe several warning lamps at once, iDrive functions dropping out (radio, navigation, phone, a speedometer reading zero), windows and trunk behaving erratically, and cars failing to start. Some owners connect the symptoms to a weak battery or a voltage drop, and others report that a dealer could not reproduce or diagnose the fault, or that an iDrive software update was needed. One campaign describes a battery cable connection at the trunk bulkhead that can work loose. Mostly reported between roughly 50,000 and 110,000 miles, with some cases at lower mileage and after the car sits unused for a period.

   Recall 12V1260004 related service bulletins

   What to check: Ask for a battery energy diagnosis report, confirm the battery is healthy and correctly registered, and have a scan check for stored fault codes across all modules, including the trunk bulkhead cable connection.

   2 excerpts from owner complaints in NHTSA records

   “Bmw 2004 545i active steering problem. My steering wheel suddenly shifted to the right. The active steering light went on. Now the car drives straight with the steering wheel tilted to the right. This is caused by the battery voltage drop. Car starts to shut down major components active steering, transmission, navigation, and I-drive system which controls the whole cars electronics. Scary when you have a 8 month old kid in a car.”

   NHTSA complaint #10367336, filed 2010-11, 82,000 miles

   “Warning notice on I drive system that there was an emergency with the lighting system and the car should be stopped immediately. Directional signals no longer worked, emergency flashers were inoperative and headlights not operating properly. …”

   NHTSA complaint #10438980, filed 2011-12, 89,655 miles
4. 4
   Transmission and drivetrain

   Low-speed transmission surge or lunge

   • 6 complaints (9%)
   • median 70,719 mi at 6.8 yrs old (6 state mileage, few)
   • 1 mention a crash, fire or injury
   • filed 2010–2011

   Owners describe the car lurching or jumping forward from a stop or while parking, sometimes feeling as if it had been hit from behind, along with occasional harsh 5-6 shifts or hesitation at low rpm. Some complaints also mention a shudder under light acceleration and a transmission fluid leak. According to the complaints, dealers variously said the behavior was normal, recommended a transmission computer reprogramming at the owner's cost, or in one case quoted a replacement transmission. Mostly reported between roughly 48,000 and 73,000 miles, typically in stop-and-go traffic, parking maneuvers or light-throttle acceleration.

   Recall 04V344000

   What to check: Drive the car from cold through several slow parking-style starts and light-throttle pulls, watching for surging or harsh shifts, and check for fluid leaks or a recent transmission service record.

   2 excerpts from owner complaints in NHTSA records

   “Transmission slams into gear when taking off from an almost stopped position causing the vehicle to jump forward violently. This has launched me into intersections and caused me to almost rear-end several vehicles. This happens on a weekly basis of daily driving. The dealership wants to reprogram the transmission computer at a cost to me(vehicle out of warranty) even though this is a known problem.”

   NHTSA complaint #10344193, filed 2010-07, 65,000 miles

   “Vehicle lunges forward at low speeds such as parking; 4 times in the last month, when I am pulling out of a parking space, the vehicle has lunged forward. 2 of those 4 times, I almost hit the vehicle in front of me. I had shifted from reverse, to drive, and just taken my foot off of the brake, and the vehicle jumped forward. The dealer has continued to say that things are ok and normal. They are not normal. …”

   NHTSA complaint #10418216, filed 2011-08, 79,000 miles
5. 5
   Exterior lighting

   Wire insulation deterioration at the headlights

   Mentioned in 4 of 59 sampled complaints

   Owners describe bare or crumbling insulation on the headlight wiring, in some cases found while changing a bulb, and note short circuits, inoperative headlights or high beams and concern about an electrical fire. Others report headlights and hazard lights flashing after start-up, turn signals not working, or an iDrive warning telling them to stop because of a lighting fault. According to complaints, one dealer wrapped the wiring with tape for a fee rather than replacing it, and a software update reportedly corrected one lighting warning. Reported from around 10,000 miles up to 164,000 miles, often noticed during bulb replacement or after the car has been parked outdoors.

   4 related service bulletins

   What to check: Open the headlight access covers and inspect the wiring insulation for cracking or exposed copper, then confirm every headlight, high beam, turn signal and hazard function works.

   2 excerpts from owner complaints in NHTSA records

   “My wife started the car and the headlights and hazard lights began flashing and turn signals did not work. Shut off and restarted the car multiple times with same effect. Drove car to Bmw dealer. Dealer technician saw same results. He disconnected battery, restarted car, rebooting the I-drive computer, and could not recreate problem.”

   NHTSA complaint #10095682, filed 2004-10, 10,000 miles

   “Wire insulation deterioration causing short, potential fire hazard, 5 separate lighting components all wiring insulation severely deteriorated causing short circuiting and inoperable headlights. Bare copper wires making contact I have an extensive history in electronics and firefighting. This issue was found while changing a bulb. …”

   NHTSA complaint #10971460, filed 2017-04, 164,000 miles

Buying note. Ask for the airbag occupancy mat and seat heater campaign status by VIN before buying, since owners often report these warnings reappear or are quoted for the repair themselves. A pre-purchase scan for stored fault codes plus a careful test of the seat heaters, headlight wiring and low-speed transmission behavior covers most of what this model year's complaints describe.

Summary written with AI from a sample of 59 NHTSA complaints for this model year (picked at random, with complaints that state a mileage and recent ones taken first), then checked automatically against the source records. Where a problem shows a complaint count, every complaint for this model year was matched with fixed keyword rules (written with AI and tested against the sample), and the mileage, age and repair figures are calculated from those complaints; owners' figures are as stated, not verified. Other counts refer to the sample. The excerpts come from NHTSA's public complaint records and are unverified; capitalisation is normalised, NHTSA staff notes are removed, and shortened text ends with “…”. Something wrong? Request a correction.