2018 model year Ā· 845+ owner reports Ā· Updated April 2026
According to Au7o's analysis of 845+ owner reports, the 2018 Kia Sedona has 2 documented known issues. No issues are rated critical, indicating generally reliable ownership. The most commonly reported issue is Automatic Transmission Shudder and Harsh Shifting with 467 owner reports. Across all issues, repair costs range from $150 to $5,500. DIY maintenance guides at au7o.io.
On the 2015-2021 Kia Sedona, the 2015-2021 Sedona with the 6-speed automatic transmission develops shuddering during gear changes, harsh shifts, and delayed engagement. The torque converter lock-up clutch wears prematurely, and the transmission valve body develops stuck solenoids. Kia released multiple TCU software updates to improve shift quality. In severe cases, torque converter or complete transmission replacement is needed.
Start with TCU software update at dealer (often free under goodwill). If shudder persists, transmission fluid flush with Kia SP-IV ATF may help. Torque converter replacement ($1,200-2,500) for shudder. Valve body replacement ($800-1,500) for shift quality issues. Complete transmission replacement ($3,500-5,500) for severe cases.
Parts and tips from 467+ owners who fixed this issue
On the 2015-2021 Kia Sedona, the 2015-2021 Sedona commonly experiences dead batteries due to a parasitic drain from the power sliding door control module. The module fails to enter sleep mode when the vehicle is off, continuously drawing 300-500mA from the battery. The battery drains overnight or within 2-3 days of sitting. The issue is often intermittent and difficult to diagnose at the dealer.
Have dealer perform parasitic draw test (should be under 50mA with all modules asleep). The power sliding door module is the most common culprit. Module replacement ($300-600) or reprogramming with updated software resolves the issue. Some owners install a battery disconnect switch ($20-40) as a temporary measure. Quality AGM battery (like Optima RedTop) better withstands repeated deep cycling.
Parts and tips from 378+ owners who fixed this issue
AIR BAGS
Kia Motors America (Kia) is recalling certain 2017-2019 Sedona, Soul, Soul EV, 2017-2018 Forte, and 2017 Forte Koup vehicles. The Air Bag Control Unit (ACU) cover may contact a memory chip on the printed circuit board and damage the electrical circuit. Circuit damage may result in deactivated air bags that will not deploy in a crash.
SEAT BELTS: REAR/OTHER:BUCKLE ASSEMBLY
Kia Motors America (Kia) is recalling certain 2019 Sedona vehicles equipped with an 8-passenger seat arrangement. The seat belt buckle for the second-row middle seat may have been improperly installed on the wrong side of the seat, preventing the proper use of the 3-point seat belt. As such, these vehicles fail to comply with the requirements of Federal Motor Vehicle Safety Standard (FMVSS) number 208, "Occupant Crash Protection."
STRUCTURE:BODY:DOOR
Kia Motors America (Kia) is recalling certain 2015-2018 Kia Sedona vehicles equipped with a power sliding door (PSD). The PSD may not auto-reverse when its closing is obstructed.
EXTERIOR LIGHTING:TURN SIGNAL
Kia Motors America (Kia) is recalling certain 2015-2017 Sedona vehicles. The Smart Junction Box (SJB) software logic may not properly interpret the signals received from the multifunction switch, which could cause the turn signal to activate in the opposite direction of what the driver intended.
ELECTRICAL SYSTEM:WIRING
Kia Motors America (Kia) is recalling certain 2015-2018 Sedona vehicles equipped with manually-adjusted front passenger seats. Over time, the Occupant Detection System (ODS) wiring harness located underneath the front passenger seat may break from the seat being occupied.
+ 1 more recalls. Check all on NHTSA.gov
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According to Au7o's analysis of 845+ owner reports, the 2018-2018 Kia Sedona has 2 documented issues. The most frequently reported are: Automatic Transmission Shudder and Harsh Shifting, Parasitic Battery Drain from Sliding Door Module. None are rated critical, but regular maintenance is recommended.
The 2018-2018 Kia Sedona has 2 known issues documented across 845+ owner reports. No issues are rated critical, suggesting generally good reliability. Regular maintenance following the manufacturer's schedule helps prevent many common problems.
Repair costs for known Kia Sedona issues range from $150 to $5,500, 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.
The 2015-2021 Sedona with the 6-speed automatic transmission develops shuddering during gear changes, harsh shifts, and delayed engagement. The torque converter lock-up clutch wears prematurely, and the transmission valve body develops stuck solenoids. Kia released multiple TCU sā¦ Repairs typically run $150-$5,500. Severity: medium.
The 2015-2021 Sedona commonly experiences dead batteries due to a parasitic drain from the power sliding door control module. The module fails to enter sleep mode when the vehicle is off, continuously drawing 300-500mA from the battery. The battery drains overnight or within 2-3ā¦ Repairs typically run $150-$700. Severity: medium.
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.
