Honda Odyssey water leak problems

Filed Nov 4, 2026 · Electrical · RI

Honda Odyssey EX-L. Vehicle was showing tailgate issues starting around 30,000 miles. Dashboard will sometimes say "Power Tail Gate Problem". When opening the power tailgate the vehicle will beep and refuse to open. Other times, the tail gate will open on it's own without any input. Upon looking into the electrical wiring on the driver's side trunk compartment, the 74970-THR-A12 2018-2024 Honda Odyssey Control Unit Power Tailgate was completely soaked with water and showed signs of corrosion. Suspected issue: Due to rain or car washing, water leaks into that compartment somehow and into the control unit and causing corrosion. Many users online are reporting this issue, suspecting leakage from the C pillar.

Filed Oct 26, 2026 · Acceleration, Driver assistance · IL

Over the course of 3 days, cruise control and lane assist systems would shut off and messages would display about adaptive cruise control, lane keep assist, lane departure warning, and collision avoidance system not working. Sometimes a transmission problem message would also become active. Sometimes the messages would be present at startup but other times the systems would show up green on the display and then the systems would shut off while driving causing the vehicle to suddenly slow down in highway traffic. The root issue seems to be a broken or malfunctioning multipurpose camera for the driver assist system. The camera has not been replaced yet to verify but related codes are active based on a code scanner and symptoms match what is expected for the camera failure. The vehicle is 6 years old with 99,400 miles at the first occurrence of the issue and does not have any windshield damage or signs of water leaking that would contribute to a failure. My primary concern is that the software completely disables cruise control when the camera for adaptive cruise and lane keep assist fails causing the vehicle to suddenly slow down rather than allow normal cruise control to continue operating and display the warning messages.

Filed Oct 20, 2026 · Body, Electrical · PA

In XXX, the power tailgate on my 2018 Honda Odyssey stopped working. I took the vehicle to authorized Honda dealer Fred Beans Honda of [XXX]. The technician documented in writing on repair order #XXX (XXX): "There is water leaking onto the power tailgate control unit. Technician found the water leak going into from the back of roof on the left side. Needs a new power tailgate control unit." Water entered through the rear body seam seals and dripped onto the power tailgate control module (P/N 74970-THR-A12). The removed module showed severe blue-green corrosion -- it does not fail on its own at 31,500 miles. Safety concern: A tailgate whose control module is destroyed by water intrusion cannot be relied on to latch or stay closed; an unlatched or unexpectedly opening tailgate while driving endangers occupants and surrounding traffic. Known defect, not isolated failure: Honda issued a TSB on rear body seam-seal water intrusion on 2018-2019 Odysseys; federal class action Case No.XXX (XXX.) covers 2018-2021 Odysseys with defective polyurethane seam seals destroying the power tailgate control module; numerous owner reports in the federal safety agency database describe identical failures. What I did: The dealer quoted $1,302.88. I first asked American Honda by phone for goodwill coverage and was denied. I repaired it myself with a genuine Honda module ($215.57, Order #XXX, XXX); total out-of-pocket $416.92. On XXX I submitted a written goodwill reimbursement request online (case #XXX, continuing prior case #XXX); on XXX Honda denied it as not covered under any campaign, even though the failure is caused by the documented seam-seal defect that is the subject of the pending class action above. What I am asking the federal safety agency: record this complaint and consider investigation/recall of the 2018-2019 Odyssey seam-seal water intrusion defect. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 18, 2026 · Electrical · CA

My 2023 Honda Odyssey (approximately 38,000 miles) has an intermittent no-crank/no-start condition. Pressing the push-button start produces no crank at all; the engine only starts on exactly the fourth press, consistently. The battery was tested and is good. The condition worsened noticeably after a high-pressure car wash, suggesting moisture intrusion. This matches Honda Technical Service Bulletin 23-023 ("Engine Does Not Crank"), which covers 2018–2023 Odysseys and attributes the defect to water entering the starter motor. The vehicle is about 2,000 miles past the 36,000-mile bumper-to-bumper warranty. I am concerned the condition will degrade without warning and leave my family — including small children — stranded. The vehicle is scheduled for diagnosis at Tracy Honda in [XXX] on XXX. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Oct 7, 2026 · Body, Electrical · CT

After a heavy rain, the rear tailgate stopped working- apparently the roof seals have cracked and water leaked into the rear part of the car, and destroyed the tailgate latch and control unit. When I was driving the car for service, the rear sensor kept beeping indicating that the tailgate was not latched properly- I was afraid it would open it, so I had to drive carefully to the dealer. Now, the dealer says it a known problem on the 22 odysseys that the seals crack and leak water into the car, but its not covered by any warranty, even though when I bought the car last year, it was a honda certified warranty. Now its a $2,630.00 job to repair this. The dealer said there was significant rust due to the leaking of the seals around the latch and controller unit. here isa link that says this problem actually goes back to 2018-2024 odysseys. [XXX] And I know it goes back as far as the 2008 model year- I had the 2008 odyssey and had the same roof seal water leak problem but the water was going into the seat belt areas. Something has to be done to stop this. INFORMATION REDACTED PURSUANT TO THE FREEDOM OF INFORMATION ACT (FOIA), 5 U.S.C. 552(B)(6)

Filed Sep 11, 2026 · Driver assistance, Electrical · IN

This vehicle is actively immobilized on private residential property with its central ADAS safety networks and Advanced Driver-Assist networks completely crashed and offline (DTC U3000-49) and active short-to-ground circuit failures (DTC B2035) rendering the passenger sliding doors completely inoperable, creating an immediate entrapment and safety hazard. These progressive component failures cascade directly from severe environmental moisture intrusion inside the rear tailgate enclosure. This exact water migration vector intersects directly with active federal safety campaign the federal safety agency Recall 26-V-423 (Rearview Camera Failure), which isolates moisture intrusion into the panel housing as the root factory manufacturing defect. A manufacturer franchise location documented active water leakage onto the Power Tailgate Control Unit and heavy corrosion on the wiring connector under a previous Repair Order but performed zero interim moisture sealing, corrosion cleanup, or terminal mitigation, allowing progressive water migration to completely destroy the wiring system harness. Furthermore, American Honda Corporate Case Management explicitly stated on a recorded verbal line that the manufacturer is denying all repair assistance to remedy these cascading safety campaign electrical defects under an active corporate case. The manufacturer is in open default of its statutory federal obligation to remedy a safety recall defect free of charge to the consumer.

Filed Sep 7, 2026 · OH

Tail gate problems Looks like there are a lot of tailgate problems with the Honda Odyssey, including water leaks that can affect the control module. I replaced the control module, but it looks like there’s a lot of information and research about this issue online.

Filed Jul 23, 2026 · Body · VA

2024 Honda Odyssey with only 24K miles has a leak in the tailgate from bad welding in the body that is gathering water in the trunk. Safety isn’t at risk but I would say that the corrosion to any electrical items are at risk which will put me and my family and others at risk of something failing. Yes the problem has been reproduced and it’s a common thread on the internet. We will be taking it to the dealership to inspect since it’s still under warranty. No messaging of this from the car except the fowl odor.

Filed Jul 13, 2026 · Locks · 32,329 miles · IL

The contact owns a 2021 Honda Odyssey. The contact stated that the rear hatch failed to release or open as needed. The contact had to enter the rear seats of the vehicle, crawl towards the rear hatch, and manually release the rear hatch from inside the vehicle. The vehicle was taken to the dealer, who diagnosed that there was corrosion on the PTG control unit and harness caused by a water leak from the roof guard stud. The dealer found that the spot weld was not sealed properly. The vehicle had not been repaired. The manufacturer was made aware of the issue. The manufacturer confirmed that the vehicle was not covered under warranty or recall. The failure mileage was 32,329.

Filed Jul 10, 2026 · Electrical, Lights · 144,411 miles · IL

The contact owns a 2018 Honda Odyssey. The contact stated that while a customer on Turo was driving the vehicle, the instrument panel warning lights flashed and the climate control system failed to function. The vehicle was restarted multiple times, but the instrument panel warning lights remained illuminated. The contact stated that while being driven, the vehicle was pulled over by law enforcement because the taillights failed completely. The vehicle was taken to the dealer, where it was diagnosed that the gauge control module had failed due to corrosion from water damage. Upon further inspection during the replacement, the dealer discovered additional failures within the body control module and the taillight wiring harness. Technicians determined that the electrical failures were caused by water leaking from the rear windshield into the tailgate area. The vehicle was repaired; however, the water leak source was not addressed or sealed. The manufacturer was notified of the failure. The failure mileage was 144,411.