[tombox]

We just drove down a hilly area and waited at a stoplight when our 2021 EX-L Passport shifted into neutral on its own. I tried pressing drive, but it just wouldn't go, and I noticed the battery light turned red.

I hit the emergency lights and still got honked at when the light turned green, so I pressed park and hit the engine start ignition. I was able to put the vehicle into drive, and then we finally got going again.

Why did this happen, and what am I supposed to do?

This was the first time it ever happened and hopefully the last, but I'd like to know what I can do to prevent this from happening again.

For reference, this has 12k miles, and I just did the b16 maintenance the other day.

Any help would greatly be appreciated.

 

[baconlord]

Few questions:

Did you remote start before leaving? If so, how long was your trip before this occurred?
Was idle stop engaged at the stop where this occurred?
Any aftermarket electrical accessories? Original battery?
Did you have the B16 service performed by dealer or yourself? If by a dealer, did they perform the idle stop recall?

 

[tombox]

Here's some unlisted dashcam footage:

20 seconds in is when it auto shifts to neutral.

-About an hour drive.
-No remote start.
-I'm not sure if auto idle kicked in, but I'm guessing this had something to do with it--I left it as is, so I didn't manually turn it off during this trip.
-Original accessories.
-0 problems before, besides a side mirror replacement by Honda.
-Original battery.

What is this idle stop recall?

I did the b16 service myself thanks to info from here and YouTube (JohnDZ adventuring).

I've had 0 problems before.
This was the second or third drive after the b16 was done.

 

[baconlord]

There is a recall to update the PCM for idle stop.

If you have a scanner, I would do an all system DTC scan first thing. If not I would start with checking to make sure your battery terminals are secured and clean them even if there is no visible corrosion. When you reinstall the terminals the top of the battery post should sit at least 1mm above the terminal. Have the battery tested as well. Those are the easy steps you can do yourself. The TCM is pretty sensitive to electrical noise... will cause weird things to happen.

Thats about all you can do as a DIY. I've never seen this issue with the 9 speeds personally.

 

[tombox]

There is a recall to update the PCM for idle stop.

If you have a scanner, I would do an all system DTC scan first thing. If not I would start with checking to make sure your battery terminals are secured and clean them even if there is no visible corrosion. When you reinstall the terminals the top of the battery post should sit at least 1mm above the terminal. Have the battery tested as well. Those are the easy steps you can do yourself. The TCM is pretty sensitive to electrical noise... will cause weird things to happen.

Thats about all you can do as a DIY. I've never seen this issue with the 9 speeds personally.

Thank you for the tips! I'll definitely give all those a shot. I did notice the engine area was a little dusty/dirty during the oil change. I've also contacted Honda America to see how they can help. I'll post updates here.

 

[fx_chip]

You should get your battery tested by the dealer and ask for a replacement if it fails the test and you are still under warranty. The main reason why the Passport and related Honda vehicles switch into neutral or switch off is due to the battery not having enough charge to restart the engine after the Idle Stop systems switches the engine off at traffic lights, the repeated engine on and off also takes a toll on battery life. You were lucky that you could still manually restart, some other members of this forum had to get a jump star when caught in the same situation, but your battery has now given you a warning of imminent demise.

 

[jayceegee]

what am I supposed to do?

Take the vehicle into your dealership ! You have a warranty -- use it ! Establish that the problem exists and use the service orders to document problems. Keep records ! If local dealership won't or can't fix the problem ask that they contact the regional office. You need to call Honda Customer Service 1 (800) 999-1009 , inform them of the problem and tell that you want a case opened. They will provide you with a case number. Consider contacting The National Highway Traffic Safety Administration.

 

[Dennis404]

Definitely get that rig into the dealer and have it checked out. Even if they don't find anything wrong, there's at least a record of it if it continues.

 

[ballisticexchris]

Get it to the dealer and have battery checked. Load test is the most accurate way of testing. Make sure you indicate you want it load tested first with a resistor heat sink type. Then immediately afterwords a digital. Just testing it with a digital will not tell the true condition of the battery. Dealers have both testing units. If it's replaced have the new battery tested the same way.

 

[tombox]

Part of the reason why I post here is to keep a record, get suggestions, and hopefully help another owner who's going through the same problem, so thank you everyone!

Here's what American Honda Motor Co said: "Based on the information provided, your vehicle is affected by the PGM-FI Idle Stop Software Update . To have the appropriate repairs performed on your vehicle, please schedule an appointment with your local authorized Honda dealership for service."




I'll have to schedule an appointment.

 

[tombox]

Update complete. Freeway Honda did a great job!

They tested the battery and said it was fine. On the drive home, auto idle kicked in once. Before, it would trigger at almost every stop light. Not a big deal, but I'm glad as long as everything works.

Before this all happened, I did receive out of the blue calls from local Honda dealerships that I visited, and they said it was time for maintenance, which I thought was weird because it was just oil change/b16 service. I never received such calls before this problem, so I wonder if this software update was what they really meant by maintenance.

Thank you again everyone!