2010 s400 hybrid wont start first instance was less than 24 hour of purchasing car from local dealer. Lights all on but no crank. Started after and two weeks later it had to be towed because it completely wont start. Mbusa forum chat and several social media groups all around the world has the same problem with this model and it comes down to an electronics power module that cost more than what…
2010 Mercedes-Benz S-Class electrical problems
moderate 10 complaints filed with NHTSA · avg repair $850 · see electrical across all vehicles →
Failure mileage
Complaints
10
Recalls
0
Avg fix
$850
When does it fail?
Of the 10 electrical complaints filed for the 2010 Mercedes-Benz S-Class, here's the actual mileage breakdown — failures cluster heaviest at 100,000-125,000 mi.
0-25k
25-50k
50-75k
75-100k
100-125k
125-150k
150k+
Each bar shows the share of total complaints filed at that mileage range. Peak failure window highlighted. Some owners report problems earlier; some make it well past 150,000 miles symptom-free. Maintenance habits and driving conditions shift the curve as much as mileage alone.
What stands out
Electrical accounts for 30% of every owner complaint on file for this vehicle — the dominant problem area across 3 categories tracked.
Among the 10 model years of Mercedes-Benz S-Class in our records for electrical problems, this one ranks #2 by owner-complaint volume.
The failure pattern owners describe
Owners of the 2010 S400 hybrid consistently report engine stalling at stop lights and while driving, with some vehicles stalling within 24 hours of purchase. The engine cuts out without warning; in one case, steering wheel locked during the stall on a highway exit, nearly causing a crash. Restart is unreliable—some owners cannot restart at all and require towing. One owner reports the vehicle stalled multiple times in Manhattan traffic.
A second major issue is complete no-crank, no-start failure while stationary or parked. Lights power on but the engine will not turn over.
Both problems trace to the power electronics module (also called the hybrid inverter power electronic control unit or power control module). Mercedes issued campaign bulletin 2012080004 covering inverter replacement on 2010–2012 S400 models, but owners report the stalling problem persists after that repair. One owner reports Mercedes eventually covered a $11K+ control module replacement after initially denying it, citing a manufacturer defect. Others found their VIN excluded from the recall despite dealer acknowledgment the part is faulty.
A third issue: the air conditioning compressor activates involuntarily once the vehicle exceeds about 40 miles of driving, regardless of season or driver input, and cannot be manually disabled. One dealer claimed this is normal.
Repair costs are steep—$11,000 for the power control module, up to $32,000 for hybrid battery replacement. One owner had warranty denied at a dealership despite holding CARB emission coverage documentation, allegedly due to minor bumper scratches.
Failure modes owners describe
Engine stalling at stop or while driving
Engine cuts out completely at traffic lights, stop signs, or during driving without warning. Steering wheel locks when stall occurs. Restart may be difficult or impossible; some owners report needing to shut everything down and restart.
When: Stalling occurs at various mileages; complaint #1 involves 37K miles; complaint #6 reports first instance within 24 hours of purchase, then again after two weeks.
Symptoms owners cite: Engine cuts off at red lights or stop signs; Engine stalls while driving, particularly on curves or exiting highways; Steering wheel locks during stall; Intermittent stalling requiring restart attempt; Longer restart times after shut-off
Codes mentioned: Power Electronics Module fault, Hybrid Inverter Power Electronic Control Unit failure
Repairs/costs cited: Power control module replacement quoted at $11,000; hybrid battery and installation quoted at $32,000. Campaign bulletin 2012080004 covered inverter replacement on some vehicles, but owners report the main stalling problem persisted post-repair.
Recalls/TSBs owners mention: Campaign bulletin 2012080004 (2010-2012 S400 models); some owners reported recalls related to power electronics module but found their VIN not covered by existing recalls. At least one owner reported manufacturer eventually covered replacement costs after dealer retained vehicle for 30 days and identified manufacturer's defect.
No-crank, no-start condition
Vehicle will not crank or start despite electrical power present (lights on). Occurs both when stationary and after driving. Can follow battery replacement or appear without prior warning.
When: Complaint #6 reports first instance within 24 hours of purchase; complaint #10 occurs while parked.
Symptoms owners cite: Lights remain on but engine will not crank; Complete inability to start vehicle; Occurs without warning
Codes mentioned: Power Electronics Module malfunction, Hybrid power control module failure
Repairs/costs cited: Towing required; parts cost exceeds vehicle value in some owner assessments.
Air conditioning malfunction
AC compressor activates involuntarily when driving beyond approximately 40 miles, regardless of set temperature or season. Cannot be manually turned off. Occurs repeatedly; dealer claims it is normal operation.
When: Complaint #8; occurs consistently after 40+ mile driving distance.
Symptoms owners cite: AC turns on automatically during highway driving; AC activates in winter despite driver preference; Manual off switch does not disable AC; Compressor continues running regardless of driver input
Recalls/TSBs owners mention: Dealer claimed normal operation; no repair attempted.
Warranty denial and coverage disputes
Owner reported warranty denial by Mercedes dealership despite vehicle eligibility under CARB 10-year/150,000-mile coverage. Denial basis cited by service manager included discretionary authority, minor cosmetic damage (rear bumper scratches), and claimed maintenance non-compliance—despite owner-presented service records and CARFAX documentation.
When: Complaint #1; vehicle is 8 years old at complaint, 37K miles.
Symptoms owners cite: Warranty coverage denied despite documented eligibility; Refusal to honor CARB emission warranty; Dealer misrepresentation of warranty terms
Repairs/costs cited: Hybrid battery replacement cost estimated at $32,000 by Mercedes parts department.
Recalls/TSBs owners mention: Initial denial; no coverage provided despite CARB mandate.
Synthesized from 10 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 6 most recent
The computer control unit for the hybrid motor has failed on my and many s400s. This causes car to stall out at stoplights or while driving. This is a safety issue.
Vehicle began to cut completely off when stopped at a red light or stop sign. It began to take longer and longer to restart when turned off and on. Eventually the vehicle would not start at all. When taken to the dealer, I was informed that the power control module was bad and the cost to replace was upward of $11,000. After speaking to many managers and my car sitting at the dealership for…
The car first started to stop intermittently without any warning at all at the traffic intersection, then I was able to start it again after shutting every thing down. Then a month later, the same thing happened again but this time I was not able to start the car again. This could be a very dangerous safety situation if the engine shuts down while I was driving on the freeway. Mercedes only…
I was driving, trying to get off the highway, I took exit which is a 270 degree circle with sharp turns, I am not driving fast at all but the car just stalled while driving, steering wheel locked and I almost fall down the hill, I almost died, this product has serious quality issues. I was driving in down town manhattan with two of my most important clients, we were going to an art auction,…
The s400 hybrid has a habit of stalling when in a stop position. This requires a complete re-start at a stop light or after having come to a complete stop. In addition the air conditioning shuts off and does not come back on until you stop for a few minutes and re-start the vehicle. The car stalling is very un-safe. The car stalls at a stop position.
Had electrical trouble with your 2010 Mercedes-Benz S-Class?
File a complaint with NHTSA → It's free, official, and how every report above got here — owner filings are the federal safety record this page is built on.
Common questions
How serious is the electrical problem on the 2010 Mercedes-Benz S-Class?
It's a documented issue but not catastrophic. 10 complaints have been filed. Repairs average $850 and most owners catch it before it causes a breakdown.
At what mileage does the electrical typically fail?
Across the 8 complaints that reported odometer mileage, most electrical failures cluster between 47,426 and 109,000 miles, with the median around 100,009. A quarter of owners report trouble before 47,426; a quarter make it past 109,000. Maintenance history matters more than the odometer alone — this is the reported failure window, not a guarantee.
What does it cost to fix?
Independent shops typically charge around $850 for electrical repairs on this vehicle. Dealer pricing tends to run 20-40% higher. The exact figure depends on the specific failure mode, parts availability, and your local labor rates. If you're outside factory warranty, an extended service contract often covers this category.
Are there any recalls related to electrical?
No active recalls currently cover electrical issues on this vehicle. The complaints filed represent owner-reported failures that haven't risen to the level of a manufacturer-issued recall — but they're still worth knowing about before you buy or budget for repairs.
Related
Complaint and recall data sourced from the National Highway Traffic Safety Administration (NHTSA)
public records database. Verify the raw federal record at
nhtsa.gov/vehicle/2010/Mercedes-Benz/S-Class.
Severity ratings are derived from reported crashes, fires, injuries, and fatalities. Repair cost estimates are
independent-shop national averages and may differ in your area. Some links on this page are affiliate links.