I started the car and I got a message stating the right front air bag malfunctioned. There is a short. I took the car in for repair, there have been several recalls on this model for the air bag, mine is not included. The air bag has shorted out. This is a huge safety issue.
2015 Mercedes-Benz CLA-Class electrical problems
severe Owners of the 2015 Mercedes-Benz CLA-Class have filed 15 NHTSA complaints about the electrical, typically surfacing around 44,000 miles at roughly $850 to repair (U.S. federal records, as of July 2026). Source: NHTSA Office of Defects Investigation. See electrical across all vehicles →
Failure mileage
Complaints
15
Recalls
0
Avg fix
$850
| Model year | electrical complaints |
|---|---|
| 2014 CLA-Class | 43 |
| 2015 CLA-Class (this page) | 15 |
| 2016 CLA-Class | 6 |
| 2017 CLA-Class | 5 |
| 2018 CLA-Class | 11 |
| 2019 CLA-Class | 4 |
1fire
When does it fail?
Of the 15 electrical complaints filed for the 2015 Mercedes-Benz CLA-Class, here's the actual mileage breakdown — failures cluster heaviest at 25,000-50,000 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
Among the 7 model years of Mercedes-Benz CLA-Class in our records for electrical problems, this one ranks #2 by owner-complaint volume.
No new NHTSA electrical complaint has been filed on this vehicle in over 7 years — the issue may be aging out of the active population.
The failure pattern owners describe
Owners describe a 2015 CLA-Class riddled with electrical gremlins across multiple systems. The collision assist engages without obstacles and can prevent the car from shifting—one owner was stranded in traffic and could not restart despite multiple attempts. Keyless entry fails intermittently, causing restart failures at traffic lights, a particular hazard with the auto start/stop feature. The audio system reboots and eventually fails entirely; dealers require costly control unit replacement instead of software updates despite an issued recall.
Safety systems are severely compromised. One owner reported flames erupting from wiring in the center console while driving; another had an earlier 2014 CLA with a similar electrical fire. The SOS emergency system no longer works but the inoperative warning blocks the speedometer, forcing manual resets each drive. An airbag short circuit remains unfixed despite recalls on the model. The trunk opens on its own during driving and parking. Wiring harness and engine control unit failures cause complete power loss and stalling that recurs immediately after dealer repair. One recall (NHTSA campaign 17V114000) has remained unapproachable for years with no parts available and manufacturer refusal to buy back affected vehicles.
Owners report command units rebooting every 2 minutes and killing the battery while still under normal use. Door locks fail, particularly rear doors that unlock without the smart key present. Some owners experience lock deactivation when parked near power lines. Dealers have been unhelpful—some claim collision assist acting up is normal—and Mercedes corporate has declined assistance.
Same Mercedes-Benz CLA-Class electrical reports on nearby years: 2014 · 2018
Failure modes owners describe
Collision Assist malfunction and false engagement
The collision assist system engages without obstacles present, displays 'Collision Assist Inoperative' message, and prevents vehicle from engaging gear. Related to ECU or software issues.
When: Intermittent, after approximately 1 year of ownership
Symptoms owners cite: Collision Assist engages without obstacles; Message 'Collision Assist Inoperative' displayed; Vehicle unable to engage gear; Multiple restart attempts required
Repairs/costs cited: Dealer claimed condition is normal; no resolution provided
Recalls/TSBs owners mention: Mercedes-Benz USA offered no solution
Check Engine light with transmission and collision assist warnings
Check engine and collision assist warning lights illuminate together, often with vehicle sputtering. PVC valve failure and transmission assist overheating documented in one case. Failures recur multiple times despite repairs.
When: Approximately 44,000 miles
Symptoms owners cite: Check engine warning light illuminated; Collision assist warning light illuminated; Vehicle sputtering; Transmission assist overheating
Repairs/costs cited: PVC valve replaced; transmission assist serviced for overheating; collision assist light reset. Failure reoccurred four times; repaired twice by dealer, once by independent mechanic
Electrical fire in center console area
Wiring underneath center console overheated and caught fire while vehicle was in motion. Owner reports similar incident with previous 2014 CLA250. Vehicle declared total loss.
When: During normal driving operation
Symptoms owners cite: Smoke smell in cabin; Flames from center console area; Fire in wiring underneath center console
Repairs/costs cited: Vehicle declared total loss by insurance
Recalls/TSBs owners mention: Previous 2014 CLA250 fire: owner went back and forth with MB corporate, ultimately traded in vehicle
Audio system reboot and complete failure
Audio system reboots intermittently, then stops working entirely and continuously reboots itself. Related to TSB 2015110001 recall; dealer requires control unit replacement rather than software update.
When: After 53,000 miles
Symptoms owners cite: Audio system reboots intermittently; Audio system stops working completely; Continuous rebooting of audio system
Repairs/costs cited: Dealer required control unit replacement instead of software update; owner paid $1,457 (50% of cost)
Recalls/TSBs owners mention: Recall TSB 2015110001 issued; Mercedes-Benz service confirmed only option was control unit replacement
SOS/Tel-Aid system inoperative with warning light interference
Mercedes no longer supports the SOS (Tel-Aid) emergency system. Inoperative warning light illuminates on each startup and blocks other safety features including speedometer. No repair available despite dealer bulletins.
When: Ongoing
Symptoms owners cite: SOS inoperative warning light displayed on startup; Other safety features blocked (speedometer, etc.); Manual reset required each time vehicle starts; Emergency alert, theft tracking, and airbag deployment notification to Mercedes non-functional
Repairs/costs cited: No fix available despite dealer bulletins
Recalls/TSBs owners mention: Mercedes no longer services this feature
Keyless remote detection failure and restart issues
Vehicle fails to detect keyless remote during operation, displaying 'Key Not Detected' message despite battery replacement and software updates. Auto start/stop feature combined with restart failure creates dangerous traffic situations.
When: Intermittent, after certified pre-owned purchase
Symptoms owners cite: Key Not Detected message displayed; Vehicle fails to restart; Keyless remote not detected during driving; Problem persists after remote battery replacement and software update
Repairs/costs cited: Battery replaced; dealer software update performed; issue recurs
Recall repair parts unavailable for extended period
Vehicle subject to NHTSA campaign 17V114000 (Electrical System, Engine and Engine Cooling) with no parts available for repair. Manufacturer unable to provide timeline for availability and declined buyback.
When: Recall notification received
Symptoms owners cite: Recall notice issued but parts unavailable
Repairs/costs cited: No repair performed; parts unavailable
Recalls/TSBs owners mention: NHTSA Campaign 17V114000 issued; manufacturer unable to confirm parts availability; declined vehicle buyback
Wiring harness and engine control unit failures with recurring stalling
Vehicle loses power and crawls to halt with all dashboard lights illuminated and engine light on. Wiring harness and engine control unit replacement provided by dealer but problem recurred identically within 3 weeks.
When: Recurring failures within 3-week interval
Symptoms owners cite: Vehicle chugs and slows to crawl; Will not accelerate; All dashboard lights illuminate; Engine light illuminated; Complete loss of power; Recurring problem after repair
Repairs/costs cited: Wiring harness replaced; engine control unit replaced; dealer later attempted pin reset online fix
Door lock failure—rear doors unlock without smart key proximity
All four doors appear locked when using smart key or keyless function, but rear doors can still be opened without the smart key present, indicating lock mechanism or electrical sensing failure.
When: Vehicle stationary with engine off
Symptoms owners cite: Rear doors can be opened despite lock engagement; Front doors lock properly but rear doors do not secure
Command unit continuous reboot and battery drain
Command unit reboots every 2 minutes whether car is on or off, draining the battery. Described as safety issue. Owner reports dozens of similar customer complaints online.
When: At 52,000 miles, just after warranty expiration
Symptoms owners cite: Command unit reboots every 2 minutes; Battery rapidly discharged; Reboot occurs with car on or off
Repairs/costs cited: Dealer charged $157 for diagnostics and quoted $500–600 for additional service
Trunk opens spontaneously during parking and driving
Trunk opens on its own whether vehicle is parked or in motion without trunk release being activated. Occurs on highways day and night.
When: Intermittent, while parked and during highway driving
Symptoms owners cite: Trunk opens without activation; Occurs while parked and while driving on 4-lane highway
Passenger front airbag short circuit and malfunction
Right front airbag malfunction message displayed with electrical short indicated. Owner reports multiple recalls exist for this model but their vehicle is not covered. Short circuit creates safety hazard.
When: Vehicle startup
Symptoms owners cite: Right front airbag malfunction message; Electrical short in airbag system; Collision prevention light displayed and remains on
Repairs/costs cited: Vehicle has had several recalls for airbags but owner's model not included
Auxiliary electrical oil pump failure with check engine light
Check engine light illuminates with auxiliary electrical oil pump failure diagnosed. Fuel smell present in cabin when engine starts.
When: At 56,000 miles, after warranty expiration
Symptoms owners cite: Check engine light illuminated; Auxiliary electrical oil pump failure; Gasoline smell inside cabin
Repairs/costs cited: Second check engine issue after warranty expired
Vehicle lock system deactivation under power lines
Vehicle locking system fails to function when parked under electrical power lines. Vehicle will not lock until moved to location without overhead power lines, indicating electromagnetic interference sensitivity.
When: When parked under power lines
Symptoms owners cite: Locking system deactivates when under power lines; Vehicle will not lock
No-start condition with electrical system failure
Vehicle will not start with no lights illuminated. Battery and alternator tested and confirmed functional, indicating other electrical system fault.
When: Vehicle startup attempt
Symptoms owners cite: Vehicle will not start; No lights illuminate; Battery and alternator confirmed functional
Repairs/costs cited: Battery and alternator checked and confirmed good
Synthesized from 15 NHTSA owner complaints — unverified consumer allegations, summarized for patterns. The verbatim filings appear below.
What owners are reporting 3 most recent
I bought Mercedes cla 2015 on jan 2015 and I drove the vehicle where my audio system used to reboot time to time once in a while but it used to come up. So I did not mention and take it to dealer that time but recently, after driving 53k mile, it completely stopped working and only rebooting itself. Later I found out there was recall about 2015/2016 cla audio recall "reference tsb no.…
1) the truck opens for no reason whether the car is parked or driven without trunk feature being activated. This happens when driving down a 4 lane highway at night and day. 2) collision prevention of light displayed & won't go off. (see attached). Google indicates that the passenger air bag has an issue.
Had electrical trouble with your 2015 Mercedes-Benz CLA-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 2015 Mercedes-Benz CLA-Class?
It's a meaningful issue. 15 complaints have been filed and the failure mode causes operational problems for owners. Repairs average $850.
At what mileage does the electrical typically fail?
Across the 9 complaints that reported odometer mileage, most electrical failures cluster between 10,500 and 56,000 miles, with the median around 44,000. A quarter of owners report trouble before 10,500; a quarter make it past 56,000. 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/2015/Mercedes-Benz/CLA-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.