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Mazda · Known Issues

2020 Mazda CX-9 Problems: 3 Known Issues

2020 model year · 2,350+ owner reports · Updated September 2026

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Issue summary

According to Au7o's analysis of 2,350+ owner reports, the 2020 Mazda CX-9 has 3 documented known issues. None of the listed issues is rated critical; this is not a complete reliability assessment. The most commonly reported issue is Transfer Case Fluid Leak (AWD Models) with 1,600 owner reports. Across all issues with published estimates, repair costs range from $150 to $2,000. DIY maintenance guides at au7o.io.

In This Article

  • CX-9 Drivetrain1
  • CX-9 Engine1
  • CX-9 Electrical1
  • Recalls1
  • FAQ
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In This Article

  • Drivetrain1
  • Engine1
  • Electrical1
  • Recalls1
  • FAQ

All 3 Known Issues

Filter:
ALL YEARS2025202420232022202120202019201820172016201520142013201220112010200920082007
Community reported
1,600 owners

On the 2007-2023 Mazda CX-9, aWD-equipped CX-9 models develop fluid leaks from the power transfer unit (PTU) / transfer case. The output shaft seal and case halves are common leak points. Low fluid levels lead to increased wear, whining noises, and eventual transfer case failure. Fluid changes are not part of the standard maintenance schedule, which allows undetected deterioration.

Common Symptoms

  • Fluid leak visible under center of vehicle
  • Whining or grinding noise from center drivetrain
  • AWD system warning light
  • Vibration at highway speed from worn transfer case components

How to Fix

Replace PTU output shaft seal and refill with Mazda FE-LS ATF. If internals are worn, PTU replacement is required. Proactive fluid changes every 30,000 miles significantly extend PTU life.

What you need to fix it

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

  • Valvoline FlexFill full synthetic API GL-5 SAE 75W-140 gear oil 902150
    OEMValvoline 902150

    First-generation 2007-2015 CX-9 AWD transfer-case lubricant matching Mazda's API GL-5 SAE 75W-140 specification Fitment/availability: Live direct product page identifies Valvoline 902150 as full-synthetic API GL-5 SAE 75W-140, $21.99, in…

    AutoZone
  • Genuine Mazda Long Life Hypoid Gear Oil SG1 0000-77-SG1-QT
    OEMMazda 0000-77-SG1-QT

    Second-generation 2016-2023 CX-9 AWD transfer-case oil specified by Mazda Fitment/availability: Live direct authorized-dealer page identifies genuine Mazda 0000-77-SG1-QT Long Life Hypoid Gear Oil SG1 at $25.39 with Add to Cart. Mazda's …

    MazdaStuff

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

Owner tips & cautions

  • TipChange PTU fluid every 30,000 miles even though Mazda does not list it in maintenance schedule
  • TipCheck for leaks at every oil change - early seal replacement saves the entire PTU. CX9Club.com AWD thread
Typical repair cost:$150 - $2,000

Research This Issue

Based on 1,600 owner reports

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceVerified1,600 owner reportsLast reported by owners Aug 2024Reviewed Feb 2026

On the 2016-2025 Mazda CX-9, the second-generation CX-9 with the 2.5L turbocharged SkyActiv-G engine can develop timing chain stretch, producing a rattle or whine at startup that may persist for several seconds. Unlike the first-gen 3.7L V6 issue, the 2.5T chain stretch is typically less severe but still requires attention. The issue is linked to extended oil change intervals and use of non-synthetic oil allowing chain guide and tensioner wear.

This issue also affects: Mazda B-Series, Mazda CX-7, Mazda Mazda6

Common Symptoms

  • Rattle or whine at cold startup lasting 2-10 seconds
  • Check engine light
  • Reduced engine performance
  • Rough idle after cold start
  • Metallic ticking noise from engine

How to Fix

Use full synthetic 0W-20 oil and change at 5,000-mile intervals (not the 7,500-10,000 Mazda suggests for normal driving). If chain rattle is present, the timing chain, tensioner, and guides should be replaced. Mazda has issued TSBs for software updates to address cold-start rattle in some model years. Inspect during valve cover gasket or cam seal service.

Typical repair cost:$800 - $2,000

Research This Issue

GoogleRedditYouTubeNHTSA
Community Reported
Medium Confidence
Community reported
750 owners

On the 2016-2023 Mazda CX-9, the power liftgate system fails to open, close, or hold position. Causes include liftgate strut motors wearing out, latch mechanism failure, and wiring harness damage in the rubber boot between body and liftgate. Cold weather exacerbates the issue as struts lose gas pressure.

Common Symptoms

  • Liftgate does not open or close with button press
  • Liftgate opens partially then reverses
  • Liftgate drops or does not hold open position
  • Error beeps when trying to operate liftgate

How to Fix

Replace power liftgate strut motors (sold as a pair). Check and repair wiring harness in the liftgate rubber boot for broken wires. Replace latch mechanism if liftgate does not latch properly.

What you need to fix it

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

  • Genuine Mazda driver-side power liftgate drive TK49-63-6EXL
    OEMMazda TK49-63-6EXL

    Left/driver powered liftgate slider when that drive is electrically or mechanically proven failed Fitment/availability: Live direct OEM page identifies driver side TK49-63-6EXL for 2016-2023 CX-9 2.5L, with its superseded suffixes listed…

    MazdaPartsNow
  • Genuine Mazda passenger-side power liftgate drive TK49-62-6EXL
    OEMMazda TK49-62-6EXL

    Confirm VIN and failed sid

    MazdaPartsNow
  • Genuine Mazda power liftgate latch TK49-62-310C
    OEMMazda TK49-62-310C

    Do not us

    MazdaPartsNow

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

Owner tips & cautions

  • TipCheck wiring in rubber boot between body and liftgate - flexing breaks wires over time
  • TipLubricate latch mechanism and strut pivots annually with white lithium grease - MazdaCX9Forum.com
Typical repair cost:$300 - $900

Research This Issue

Based on 750 owner reports

GoogleRedditYouTubeNHTSA
Community Reported
High ConfidenceVerified750 owner reportsLast reported by owners Oct 2024Reviewed Feb 2026
NHTSA Recalls1 recall

SEATS:MID/REAR ASSEMBLY

Mazda North American Operations (Mazda) is recalling certain 2020-2021 CX-9 vehicles equipped with 60/40 split bench second-row seats. The left-side second-row seat may unexpectedly slide forward during a crash. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard number 210, "Seat Belt Assembly Anchorages."

Campaign #21V75000027/09/2021

Enter your VIN at NHTSA.gov to check recalls specific to your vehicle.

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Other Mazda Models

Mazda CX-530Mazda CX-6027Mazda CX-5026Mazda MX-5 Miata22Mazda MX-621Mazda Mazda319

Frequently Asked Questions

What are the most common Mazda CX-9 problems?

According to Au7o's analysis of 2,350+ owner reports, the 2020 Mazda CX-9 has 3 documented issues. The most frequently reported are: Transfer Case Fluid Leak (AWD Models), Timing Chain Stretch and Rattle (2.5L Turbo SkyActiv), Power Liftgate Failure. None are rated critical, but regular maintenance is recommended.

Is the Mazda CX-9 reliable?

The 2020 Mazda CX-9 has 3 known issues documented across 2,350+ owner reports. None of the matching records is rated critical; this is not a complete reliability assessment. Regular maintenance following the manufacturer's schedule helps prevent many common problems.

How much does it cost to fix common Mazda CX-9 problems?

Repair costs for known Mazda CX-9 issues range from $150 to $2,000, 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 is the 2007-2023 Mazda CX-9 Transfer Case Fluid Leak (AWD Models)?

AWD-equipped CX-9 models develop fluid leaks from the power transfer unit (PTU) / transfer case. The output shaft seal and case halves are common leak points. Low fluid levels lead to increased wear, whining noises, and eventual transfer case failure. Fluid changes are not part o… Repairs typically run $150-$2,000. Severity: medium.

What is the 2016-2025 Mazda CX-9 Timing Chain Stretch and Rattle (2.5L Turbo SkyActiv)?

The second-generation CX-9 with the 2.5L turbocharged SkyActiv-G engine can develop timing chain stretch, producing a rattle or whine at startup that may persist for several seconds. Unlike the first-gen 3.7L V6 issue, the 2.5T chain stretch is typically less severe but still req… Repairs typically run $800-$2,000. Severity: medium.

What is the 2016-2023 Mazda CX-9 Power Liftgate Failure?

The power liftgate system fails to open, close, or hold position. Causes include liftgate strut motors wearing out, latch mechanism failure, and wiring harness damage in the rubber boot between body and liftgate. Cold weather exacerbates the issue as struts lose gas pressure. Repairs typically run $300-$900. Severity: low.

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 sourced from 2,350+ owner reports, NHTSA recalls, TSBs, and automotive forums.