Battery drains after being parked overnight, 58,000 miles, dealer maintained since new. Driven by a little old lady until I bought it. Took it to the dealer and they replaced one of the seat modules. Soon afterward, the problem recurred. Took it back to the dealer and they said it was a defective fuse box and replaced it for $650. Went to pick up the car and the battery was dead again. After some complaining, they refunded the bill. They looked at it again and said the problem was somewhere in the dashboard and it would cost $2300 just to take it apart and look for a bad module. They offered $2300 trade in toward a new or CPO car, and said my car would be sent to the crusher. I took the car back and installed a remote operated battery cutoff, and have been driving it ever since. Other than disturbing the engine computer, it's been running well for three years and 20,000 miles. Lovely car otherwise.
Mercedes Benz C320 battery drain problems
31 of the 187 owner complaints about the Mercedes Benz C320 describe battery drain or dead battery, most of them for the 2002 model year.
- owner complaints
- 31
- worst model year
- 2002
- typical repair cost reported
- $900
- typical mileage
- 65,000
By model year
Often reported together
What owners say
Battery draining
The seat control units do not shut off and continually drain the battery. This is a widespread problem for this model car.
My 2001 mercedes-benz c320's battery was constantly going bad and having to be jumped after not starting it or driving it for approx. 24 hours. Finally, after a certified mercedes mechanic investigated the problem, he informed me that the problem originated from the driver's seat module, which was draining my battery. He informed me that if I unplugged it for the time being, my battery would no longer drain. Sure enough, after unplugging the seat module, I no longer had issues with my battery draining. The seat module controls seat adjustments as well as steering wheel adjustments, so this is very inconvenient, and unsafe, because there are times, when I have to plug the module in adjust my seat or steering wheel, and it does not work, and I'm stuck with the seats or steering wheel in an uncomfortable position. I have also had problems with brake (stop) lights, turn signal lights, etc., in which the vehicle indicator states that particular lights are malfunctioning, and then after awhile it goes away, and then days later, the lights are inoperable again. I have spent quite a bit of money replacing bulbs. I originally purchased this vehicle in 2004 when it was still under warranty.
Tl* the contact owns a 2002 mercedes benz c320. The contact stated that the vehicle failed to start. The vehicle was taken to the dealer where the technician diagnosed that the power seat module was draining the battery and as a result, it needed to be replaced. The manufacturer was not made aware of the failure. The vehicle was not repaired. The failure and current mileage was 81,000.
Power control seat & steering column module/regulator went out & before it did it use to drain the battery where car wouldn't start if sat for less than 24hrs, so had to unplug but now the entire system doesn't work plugged in. I can barely reach the pedals to drive properly, this is a safety hazard & needs to be a recall. It also needs to be a way to manually adjust. Thank you
Tl* the contact owns a 2002 mercedes c320. The contact stated he had to replace the battery in the vehicle several times. The dealer stated the seat controls for the passenger seat drained the battery and the seat control module needed to be replaced. The failure mileage was 89,000 and the current mileage 90,904.
Tl* the contact owns a 2001 mercedes benz c320. The contact stated that she attempted to start the vehicle but it would not start. The dealer sent someone to charge the battery. The contact stated that the failure recurred three additional times. The vehicle was taken to the dealer for inspection where they stated that the driver's seat was draining the battery. The dealer disconnected the fuse for the seat but the contact was unable to adjust the seat when needed. The manufacturer was notified but provided no assistance. The failure mileage was 64,000. The VIN was unavailable.
On 1/14/2012 car wont start battery dead, call aaa tow truck. Jump battery ok used cared next day and on faul come up on my cars troulbe screen to indicated that I had any other trouble in any system it the car, we when to fl on the on the 16 of january car was home (in ny) son was going to take of house and start car once a week. Received phone call from my son on 1/17/2012 car wont start,battery dead, and key wont turn. On 4/21/2012 come home from fl fround dead car and transmistion leaking.called mercedes benz for a toe to the shop.this is thr thired battery since a have this car.battery was under warranty.it was chaneg lest then a year ago. M/b shop informed me battery was dead. Cause my seat modules shorted, to replace modules was cost $1200. I feel that the battery cause this trouble and the the modules should be replaced by b/m at no cost to me.
After replacing my battery I learned on line that the mercedes have a problem with their seats where they drain the battery and cannot hold a charge. After having my car jump started 5 times I took it to my mechanic who confirmed it was being drained by the seats....makes no sense. However, apparently it is happening to many people with this year and make of car. Mercedes is not standing behind their defective product. This is not ok....
Related recalls
No recalls on record for this model year.
Questions about the Mercedes Benz C320 battery drain
Which Mercedes Benz C320 years have battery drain or dead battery problems?
The model years with the most reports are 2002 (20 complaints), 2001 (10 complaints) and 2003 (1 complaints).
How much does it cost to fix battery drain or dead battery on the Mercedes Benz C320?
Owners who mentioned a price put the repair at about $900 (median of 10 complaints that include a dollar amount). Costs vary with mileage, warranty and where the work is done.
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