2021 Honda Odyssey Electrical System

My rear hatch for the trunk was filling up with water every time it rained. Took it in to be looked at and they found the door wasn’t sealed during manufacturing and they sealed it. The water damage was already done and buttons for all things no longer lifts or opens the trunk door. My dash displays “ power tailgate problem” and nothing works to open it. I have to do it manually and I’m afraid it will cause further problems to the door.

The contact owns a 2021 Honda Odyssey. The contact stated while at a stop light and depressing the brake pedal, the engine turned off; however, once the accelerator pedal was depressed, the Auto START/STOP failed to operate as intended. The contact turned off and restarted the vehicle and the vehicle started to work as intended. No warning light was illuminated. The vehicle was not taken to a dealer or independent mechanic to be diagnosed. The vehicle was not repaired. The manufacturer was not notified of the failure. The approximate failure mileage was 32,000.

After my van sit at home all day while it was raining. I went out side to put something in the back of the van and the tail gate wouldn't open had warning symbol on the dash board. I only have 61,729 miles on my van and no accidents

The main screen went black for 3 mins while driving. Booted halfway back up then crashed again. Booted up again and then worked. Its done this 3 times and I've had van for 6 days. 32k miles one owner. Mint looking

The contact owns a 2021 Honda Odyssey. The contact stated that while attempting to start the vehicle, the engine failed to crank. There were no warning lights illuminated. The vehicle was towed to a local dealer, where it was diagnosed, and the contact was informed that the starter was faulty and needed to be replaced. The vehicle was not repaired. The manufacturer was notified of the failure. The approximate failure mileage was 66,000.

On 28-Dec-2024 I noticed the power tailgate stopped working on my 2021 Honda Odyssey. I tried to press the power tailgate button on the key fob, the button on the driver's side control panel, and the button on the tailgate itself, but none of them works. I did some research online and found out it's a common problem in 2018 to 2021 models and the cause was the failed Power Tailgate Control Unit due to water leakage through the cracks on the vehicle body. I opened mine and found there was water in the control unit box which might have caused short on the circuit board. I bought a new control unit a week later and it fixed the issue.

The vehicle's Auto Idle Stop (AIS) malfunctioned. The vehicle stalled and required a complete "shut down" to restart. The vehicle was first in line at a traffic light. The AIS system engaged. When I took my foot off the break to "go" when the light turned green, the car stalled. An error message popped up, indicating that I needed to shift the car into "park". I did so and the car did not start. I attempted to turn the car off several times, while in park and my foot depressing the break pedal. The car would not turn off. After three minutes of attempting to turn off the car and waiting, I was finally able to successfully start the car. I was traveling with my four young children, three of them in child car seats. I was nearly rear ended by one vehicle, despite having my hazard flashers on, because my car stalled at a traffic light when it was green. Two cars drove around me who were also stopped behind me at the traffic light. Another car came up to the traffic light and my vehicle and nearly rear ended me with my four young children in the car. This is the third time that this exact issue has occurred in my car. I brought it to my local Honda dealership on the same day that the issue first occurred. They inspected it but were unable to replicate it. They said they would make note of it but had not heard of such an issue. I had no idea this could be reported on this website. I was never told about this otherwise I would have reported this on the day that each of the two previous incidents occurred. This issue originally occurred the first time approximately 10/2022 and again for the second time approximately 4/2023. It just occurred for the third time today, 7/14/0225.

Tailgate would not work (electronically or manually) Other Odyssey owners have had similar problems, some included tailgate opening on its own There were no problems until it just wouldn’t open one day Dealer replaced module for $700+

Auto Idle Stop not restarting after shutting the engine down.

Car has completely shut off when the auto start/stop engaged after coming to a stop at a red light/stop sign on multiple occasions. Everything shut completely off, no radio, lights, etc. Had to push the start button multiple times to turn the car back on. Please investigate as I have read of this happening to many other people with 0 solution from Honda. This is a defect and should be recalled/fixed.

On 1/31/25 our rear tailgate automatically opened upon parking the car in our garage. Later that day, the tailgate would no operate properly and had to be manually opened. The key fob was functional and could operate all other doors in the car, except the tail gate. Later that day, while the car was parked in our garage, the tailgate started operating by itself, without pressing any buttons on the remote control key fob. It would open and close by itself and repeat the entire sequence over and over again. Upon turning on the car, the display identified a Power Tailgate Problem. The problem was reproduced by the Olathe Kansas Honda dealership. We took it to the dealership today and they diagnosed the problem, stating it is a Gate Control Unit failure (error code P1378 and P1379). Dealer confirmed what we experienced. We documented the safety problem via video. We were able to temporarily fix the issue by disconnecting the car battery overnight and reconnecting it the following morning. Safety concerns - This is a concerning issue as the tail gate could open by itself while driving, and/or could open by itself when you have the car parked in public, allowing theft of any items left inside. It could also open while someone is driving along a parking lot and cause an accident. There was no warning light prior to the malfunction of the tail gate control unit. We have found online that there may be a class action lawsuit regarding this issue.

All of the safety system and efficiency systems had failures which made us take to our local Honda dealership for evaluation. After the first visit we were told that they could not find the problem, although they saw all of the error messages. The error messages appeared again 3 days later so we took it back to our local Honda dealership. This time one of the service reps had seen that problem before and said it probably was due to water entering the rear trunk circuit board controller and shorting out the connections. This was confirmed by a service tech during the 2nd evaluation. After research this is apparently a common issue. We had to pay approximately $700 to fix the situation because Honda does not have this issue as a recall. We believe this is a clear design error that allows water to enter the circuit board housing. This created a dangerous situation as the head lamps as well as the driver safety features and direction signals intermittenly worked due to the shorted out circuit board.

Upon going to start my vehicle it would not start. I ended up jump starting the car and going to buy a new battery. I replaced the battery even though repair facility stated battery was at 78% and in good state. Two days later I went to start the van again and the battery was again dead. I jumped the car to get it started and have had to continually jump start the car due to no start issue. The alternator is showing a constant 14.3 volt charge when running but the battery continues to die. Has left my family stranded multiple times in the past week. No known cause or fix.

The 'infotainment" system turned off stating "network connection lost." The speakers then started making a VERY loud crackling sound that could not be controlled with the volume button. It was very distracting to the driver--sounded like rocks hitting the windshield. When the infotainment system was off, the blindspot monitor and back-up camera stopped functioning. This has happened several times.