Au7o mascotAu7o
Known IssuesTest Hub demo
  1. Au7o
  2. /
  3. Known Issues
  4. /
  5. Mercedes-Benz
  6. /
  7. EQC
Mercedes-Benz · Known Issues

2019-2023 Mercedes-Benz EQC Problems: 7 Known Issues

2019-2023 model years · NHTSA recalls, manufacturer TSBs, and owner forum reports · Updated August 2026

Share:@au7o.io

All years · All trims · All engines

Choose the year and equipment for your written issues and visual request.

No email neededHow interest is saved

Interest applies to the selected vehicle and configuration; it is not a reservation. Voting stores a first-party identifier for up to 180 days to prevent repeat votes. No account or email is needed. Clearing cookies or using another device may count separately. Privacy

Visual coming soon

Your interest helps us choose what to build next.

Visual Known Issues · Coming soon

$4.99/month plus taxes at launch · No payment today

Choose a year to request this visual. Trim and engine are optional; omitted trim is Not specified.

Preview the XT6 example
Known IssuesMotorcycle IssuesDTC LookupDrivePricingAboutTermsPrivacyCookiesConsentData rightsCopyrightFeedback
Share:@au7o.io

Vehicle data and repair guidance on this site are compiled with AI assistance and may contain errors. Always verify with your service manual or a qualified mechanic.

Data protection representation

DataRep representative in the United KingdomDataRep representative in the European Union
Au7o · 2026
Built for DIY mechanics. Privacy-first.
Explore free Hub demo

Choose your vehicle configuration

Choose a year to request this visual. Trim and engine are optional; omitted trim is Not specified.

Which vehicle’s visual would you like?

Choose from our year, make, model and trim catalog. This does not change the page underneath or mean a visual is already available.

Choose a vehicle configuration to continue. No request has been submitted.

Optional email notification

Choose a year to request this visual. Trim and engine are optional; omitted trim is Not specified.

Which vehicle’s visual would you like?

Choose from our year, make, model and trim catalog. This does not change the page underneath or mean a visual is already available.

Choose a vehicle configuration to continue. No request has been submitted.

Issue summary

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2019-2023 Mercedes-Benz EQC has 7 documented known issues, with 4 rated critical. The most serious are High-voltage battery housing corrosion from inadequate sealing, Side-impact crash sensor connector not latched (airbag/safety system fault), Electric drive module coolant leak (motor reducer sealing) ($0-$0 repair) and Electric power steering wiring harness water ingress / short circuit ($0-$0 repair). Across all issues with published estimates, repair costs range from $60 to $300. DIY maintenance guides at au7o.io.

In This Article

  • EQC Electrical2
  • EQC Safety/Recalls1
  • EQC Drivetrain1
  • EQC Steering1
  • EQC Brakes1
  • EQC HVAC1
  • FAQ
Get Started
Back to top

In This Article

  • Electrical2
  • Safety/Recalls1
  • Drivetrain1
  • Steering1
  • Brakes1
  • HVAC1
  • FAQ

All 7 Known Issues

Filter:
ALL YEARS20232022202120202019

Australian recall REC-001692 directly identifies 2019 EQC400 vehicles whose high-voltage battery housing sealing can degrade, allow moisture entry, cause corrosion and potentially create an electrical short and fire risk. Owners of affected VINs are directed to an authorized dealer for the recall remedy.

Common Symptoms

  • VIN recall eligibility checked
  • battery or isolation warning documented
  • high-voltage work left to qualified personnel

How to Fix

Check the VIN against recall REC-001692 and arrange the free authorized-dealer remedy if affected. High-voltage battery inspection and sealing work require trained personnel. Do not buy a battery housing, sealant or battery assembly from this page; the remedy and parts are dealer/VIN-specific.

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceVerifiedReviewed Aug 2026

EQC owners report recurring 'Auxiliary Battery Malfunction' warnings, sometimes appearing repeatedly (every minute or so), along with dimming lights, intermittent infotainment glitches and occasional no-start. The small 12V auxiliary (AGM) battery that powers electronics weakens or its connections corrode/loosen; because EV electronics constantly draw on it, a marginal 12V battery causes a cascade of warnings. Resting voltage in the ~11.6V range indicates a failing battery.

Common Symptoms

  • Recurring 'Auxiliary Battery Malfunction' warning
  • Dimming lights
  • Intermittent infotainment/electronics glitches
  • Occasional no-start

How to Fix

Check and clean/tighten the 12V auxiliary battery terminals first (loose/corroded connectors mimic a dead battery). If resting voltage is low (<12.2V) or faults persist after charging, replace the auxiliary battery with the correct AGM spec, then clear fault codes with a diagnostic tool. Typical replacement is inexpensive.

What you need to fix it

Only diagnosis- and fitment-reviewed repair parts are linked here.

  • Genuine Mercedes-Benz 12V 1.2-Ah auxiliary/backup battery 000000004039
    OEMMercedes-Benz 000000004039 / N000000004039

    Small N293 backup-battery branch only after diagnosis and the removed part/VIN confirm 000000004039 or its 000000009504 supersession Fitment/availability: The inspected direct product result identifies genuine Mercedes 000000004039, SKU …

    FCP Euro

As an Amazon Associate, we earn from qualifying purchases; other part links may also earn au7o a commission. Confirm fitment by VIN before buying.

Typical repair cost:$60 - $300

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceVerifiedReviewed Jun 2026

Romanian ANPC / Mercedes campaign 9193112 includes model 293 (EQC) and identifies an electrical connector at a side-impact sensor that may not be coupled to specification, allowing detachment over vehicle life and delaying restraint-system activation in a side impact. Australian recall REC-004958 independently identifies the affected 2020 EQC and the same side-crash-sensor electrical-connector risk.

Common Symptoms

  • VIN campaign status checked
  • airbag or restraint warning documented
  • door side-impact sensor connector inspected under the recall

How to Fix

Check the VIN with an authorized Mercedes-Benz dealer for campaign 9193112 and complete the recall inspection and repair if applicable. Do not buy a crash sensor, connector or airbag component from this page; eligibility and the exact part are dealer/VIN-specific.

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceVerifiedReviewed Aug 2026

Due to manufacturing deviations in the electric drive module, the internal cooling circuit can have insufficient sealing, causing coolant to leak — owners likened it to an EV 'oil leak.' If coolant enters the motor it can reduce the high-voltage system's insulation resistance over time; in extreme cases the drive module output power is reduced or the vehicle will not start. This triggered a very large China recall of 10,104 EQCs (later expanded to also cover EQA/EQB) for units built 30 Nov 2018 – 15 Dec 2021.

Common Symptoms

  • Coolant leak / fluid under vehicle
  • Reduced drive power / power limitation warning
  • Vehicle may not start in extreme cases
  • High-voltage / drive system warning

How to Fix

Recall remedy: Mercedes service partners replace the affected electric drivetrain/drive module (a labor-intensive job, quoted up to ~18 hours). Owners outside China with leaks should have the drive unit inspected for coolant seepage under warranty.

Typical repair cost:$0 - $0

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceVerifiedReviewed Jun 2026

The wiring harness for the electric power steering (steering control unit) can be damaged during the production process, allowing water/moisture into the harness. This can cause a short circuit and a sudden loss of electric power steering assistance, plus an increased fire risk. Affected EQC 400 4Matic units were built mainly in late 2019 to early 2020 (the DVSA/UK action cites Dec 2019–Mar 2020 build dates; the EU recall via car-recalls.eu is dated 13/02/2021 and a follow-up 06/12/2021). Mercedes issued multiple steering-related recall actions for the EQC.

Common Symptoms

  • Loss of / heavier power steering assistance
  • Red steering warning in instrument cluster
  • Burning smell or fire risk
  • Steering fault message

How to Fix

Recall remedy: dealer inspects the steering control unit wiring harness and replaces it if damaged, at no cost. Drivers get a red instrument-cluster warning before failure in many cases; the vehicle should be taken in immediately if shown.

Typical repair cost:$0 - $0

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceVerifiedReviewed Jun 2026

Owners widely report a non-linear, inconsistent brake pedal: 'spongy' or 'mushy' at the top of travel then suddenly 'grabby' lower down, making smooth stops hard. This stems from the EQC's brake-by-wire system blending regenerative and friction braking; the transition is not always seamless. Some owners also describe the system juddering or making a loud mechanical noise as the ABS/blending engages, and a different pedal feel on the first brake application after start-up. This is a recognized trait across Mercedes EQ models, not a one-off defect.

Common Symptoms

  • Spongy/mushy brake pedal at top of travel
  • Sudden grabby braking lower in pedal travel
  • Brake judder or loud mechanical noise during blending
  • Different pedal feel on first stop after start-up

How to Fix

Mercedes states some variation in pedal feel is normal for the brake-by-wire/regen system. Software updates have been applied to improve blending; persistent judder/noise should be diagnosed at a dealer (brake control unit / actuator checks). Owners can also adjust regen via the steering-wheel paddles to suit their driving.

Typical repair cost:$0 - $300

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceVerifiedReviewed Jun 2026

EQC owners report large winter range drops — commonly 25-30%+ at around -10C, with real-world examples falling from ~230-239 miles to ~180-190 miles. While some cold-weather loss is normal for any EV, owners and reviewers single out the EQC's heat-pump/PTC heater strategy as relatively inefficient (the car leans on the energy-hungry PTC heaters rather than the heat pump), and the EQC lacks the flexible departure preconditioning of some rivals, making winter range management hands-on. Independent Norwegian cold testing measured ~25% loss.

Common Symptoms

  • Range drops 25-40% in cold weather
  • Reduced displayed range with heater on
  • Slow cabin warm-up
  • High energy consumption in winter

How to Fix

Not a defect with a single fix — mitigate by preculating/preconditioning the cabin and battery while plugged in, using seat/steering-wheel heating instead of cabin heat, and selecting eco/range modes. Some MBUX software updates improved heating logic; ensure the car is on current software. Verify the heat pump is functioning if losses are far beyond ~30%.

Typical repair cost:$0 - $0

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceVerifiedReviewed Jun 2026
🔧
A mechanic who knows YOUR exact car
Answers tuned to your year, make, model & trim — not generic advice. Save your garage so it always has the right context.
Get ahead of Mercedes-Benz EQC problems — free
Leave your email and we'll alert you the moment there's a new recall or known issue for your Mercedes-Benz EQC. Free, no account needed.

Don't see your problem? Describe your symptoms to get a diagnosis, or get a full repair guide.

Other Mercedes-Benz Models

Mercedes-Benz GLE24Mercedes-Benz E-Class23Mercedes-Benz GLS23Mercedes-Benz Sprinter22Mercedes-Benz A-Class22Mercedes-Benz GLC22

Frequently Asked Questions

What are the most common Mercedes-Benz EQC problems?

According to Au7o's research across NHTSA recalls, manufacturer TSBs, and owner forum reports, the 2019-2023 Mercedes-Benz EQC has 7 documented issues. The most frequently reported are: High-voltage battery housing corrosion from inadequate sealing, Side-impact crash sensor connector not latched (airbag/safety system fault), Electric drive module coolant leak (motor reducer sealing). Of these, 4 are rated critical and should be addressed promptly.

Is the Mercedes-Benz EQC reliable?

The 2019-2023 Mercedes-Benz EQC has 7 known issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports. 4 issues are rated critical: High-voltage battery housing corrosion from inadequate sealing and Side-impact crash sensor connector not latched (airbag/safety system fault) and Electric drive module coolant leak (motor reducer sealing) and Electric power steering wiring harness water ingress / short circuit. Prospective buyers should inspect for these issues and factor potential repair costs into their purchase decision. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

How much does it cost to fix common Mercedes-Benz EQC problems?

Repair costs for known Mercedes-Benz EQC issues range from $0 to $300, depending on the specific problem and whether you choose DIY or professional repair. Au7o provides step-by-step DIY maintenance guides that can help reduce repair costs.

What year Mercedes-Benz EQC is the most reliable?

Reliability varies across model years of the Mercedes-Benz EQC. Based on documented issues, problems are most commonly reported in earlier model years. Au7o recommends checking the specific known issues for your target year before purchasing, and having a pre-purchase inspection performed by a qualified mechanic. Our known issues database covers the 2019-2023 Mercedes-Benz EQC with 7 documented issues compiled from NHTSA recalls, manufacturer TSBs, and owner forum reports.

What is the 2019 Mercedes-Benz EQC High-voltage battery housing corrosion from inadequate sealing?

Content on this page was compiled with AI assistance using NHTSA complaints, TSBs, owner reports, and public automotive data. While we strive for accuracy, this information may contain errors. Always verify repair procedures and specifications with your vehicle's service manual or a qualified mechanic.

Data compiled from NHTSA recalls, manufacturer TSBs, automotive forums, and AI-assisted research. No aggregated owner-report counts available for this vehicle yet.

Australian recall REC-001692 directly identifies 2019 EQC400 vehicles whose high-voltage battery housing sealing can degrade, allow moisture entry, cause corrosion and potentially create an electrical short and fire risk. Owners of affected VINs are directed to an authorized deal… Severity: high.

What is the 2020 Mercedes-Benz EQC Side-impact crash sensor connector not latched (airbag/safety system fault)?

Romanian ANPC / Mercedes campaign 9193112 includes model 293 (EQC) and identifies an electrical connector at a side-impact sensor that may not be coupled to specification, allowing detachment over vehicle life and delaying restraint-system activation in a side impact. Australian… Severity: high.

What is the 2019-2021 Mercedes-Benz EQC Electric drive module coolant leak (motor reducer sealing)?

Due to manufacturing deviations in the electric drive module, the internal cooling circuit can have insufficient sealing, causing coolant to leak — owners likened it to an EV 'oil leak.' If coolant enters the motor it can reduce the high-voltage system's insulation resistance ove… Repairs typically run $0-$0. Severity: high.

What is the 2019-2021 Mercedes-Benz EQC Electric power steering wiring harness water ingress / short circuit?

The wiring harness for the electric power steering (steering control unit) can be damaged during the production process, allowing water/moisture into the harness. This can cause a short circuit and a sudden loss of electric power steering assistance, plus an increased fire risk. Repairs typically run $0-$0. Severity: high.

What is the 2019-2023 Mercedes-Benz EQC Inconsistent brake-by-wire pedal feel (regen/friction blending)?

Owners widely report a non-linear, inconsistent brake pedal: 'spongy' or 'mushy' at the top of travel then suddenly 'grabby' lower down, making smooth stops hard. This stems from the EQC's brake-by-wire system blending regenerative and friction braking; the transition is not alwa… Repairs typically run $0-$300. Severity: medium.

What is the 2019-2023 Mercedes-Benz EQC 12V auxiliary battery malfunction / drain?

EQC owners report recurring 'Auxiliary Battery Malfunction' warnings, sometimes appearing repeatedly (every minute or so), along with dimming lights, intermittent infotainment glitches and occasional no-start. The small 12V auxiliary (AGM) battery that powers electronics weakens… Repairs typically run $60-$300. Severity: medium.

What is the 2019-2023 Mercedes-Benz EQC Heavy cold-weather range loss and inefficient heat pump?

EQC owners report large winter range drops — commonly 25-30%+ at around -10C, with real-world examples falling from ~230-239 miles to ~180-190 miles. While some cold-weather loss is normal for any EV, owners and reviewers single out the EQC's heat-pump/PTC heater strategy as rela… Repairs typically run $0-$0. Severity: low.