Today I replaced the ATF on my 2020 Hybrid EX-L.
Much thanks to @Hunter Mike who provided service details regarding this job in an old thread, which I’ll also readdress here for everybody’s reference.
I’d say overall this job is no more difficult than changing oil, so anybody who has experience with oil change can get hands on it.
Tools you’ll need:
Flathead and Phillips screwdrivers. They are used to remove the whole metal undercover. This is unlike oil/filter change which only needs to remove the little triangular guard cover.
A long neck funnel or a fluid pump. There are two ways to fill in new ATF: through a rubber hole on top of the AT case or the check level hole at side of the case. I did the former way although my funnel was a bit too fat to squeeze in. I had to unplug several connectors for easy access. If you want to strictly follow the book then get a fluid pump to fill in through the side check level hole.
A 3/8” breaker bar and 17mm socket. The drain plug is 3/8” square while the check level plug is 17mm.
A washer for the drain plug, which should be 18mm. As for the filler hole, I didn’t replace it but I imagine the same 14mm washer for engine oil drain plug (also 17mm) would fit.
3 qt of Honda ATF-DW1. There’s no point of trying anything wild; it won’t make your hybrid downshift quicker.
====
Now to the procedures.
1. Lift up all 4 corners in the air and try best to make the vehicle parallel to the ground. This is because you’ll need the filler hole to check fluid level, which assumes the vehicle is NOT tilt.
This wasn’t easy — I only had a floor jack and 4 jack stands. Thankfully, the little 12V bottle jack I got from Costco was quite powerful and helped to lift up one side front so that my floor jack gained access to the front center jack point.
Note: ALWAYS double check the jack points before it is lifted by the tool. Try your best to align the jack centered at the jack point to prevent any slip.
2. Remove the large metal undercover using screwdrivers.
Note: there are 2 Philips screws which are notorious for seizing up or breaking the female threads inside. I had this problem with my 2017 Civic before. Therefore, try using something like WD40 silicone spray to help mitigate their rust and do NOT over tighten them!
3. Remove the drain plug. It is almost at the bottom and facing against the engine, i.e. facing the vehicle’s right side. It’s located quite to the front vs engine oil drain plug. There is only one plug which has 3/8” square female around that area so rest assured that you won’t unplug the wrong one.
The image shown below, filler plug is facing left while drain plug is facing right.
![Image]()
While draining old fluid out, remove the filler hole plug with 17mm socket. It is at the opposite side of the transmission case vs drain plug, and located at a higher position. It is facing the vehicle’s left side. There is a ‘v’ shape protruding beneath this plug which can help you find it.
4. Replace the washer for drain plug and tighten it to 36 lb ft.
Now fill the new ATF into the case. With a fluid pump, fluid can be pumped into the case through the filler hole. Alternatively, you can find a rubber cap from the top of transmission case when looking down into the engine bay, and fill with a long neck funnel.
No.12 is the rubber filler cap.
![Image]()
I suggest just dump all 3 qt into the case, and let excess fluid come out by itself. You don’t wanna save half bottle until next fluid change anyway.
5. Tighten the fill hole plug to 32 lb ft. As for the washer, it isn’t required to replace so just make your own decision. If you used the rubber hole, also cap it.
6. Install the metal undercover.
====
I feel that after ATF change my vehicle shows significant better shifting from cold start. In the past month when temperature dropped, it had sensable jerk at highway speeds after I pulled out in the morning. I see this always happened with the clutch engagement.
Therefore, in the future I plan to stick with 1 ATF change every 3 oil changes.
Much thanks to @Hunter Mike who provided service details regarding this job in an old thread, which I’ll also readdress here for everybody’s reference.
I’d say overall this job is no more difficult than changing oil, so anybody who has experience with oil change can get hands on it.
Tools you’ll need:
Flathead and Phillips screwdrivers. They are used to remove the whole metal undercover. This is unlike oil/filter change which only needs to remove the little triangular guard cover.
A long neck funnel or a fluid pump. There are two ways to fill in new ATF: through a rubber hole on top of the AT case or the check level hole at side of the case. I did the former way although my funnel was a bit too fat to squeeze in. I had to unplug several connectors for easy access. If you want to strictly follow the book then get a fluid pump to fill in through the side check level hole.
A 3/8” breaker bar and 17mm socket. The drain plug is 3/8” square while the check level plug is 17mm.
A washer for the drain plug, which should be 18mm. As for the filler hole, I didn’t replace it but I imagine the same 14mm washer for engine oil drain plug (also 17mm) would fit.
3 qt of Honda ATF-DW1. There’s no point of trying anything wild; it won’t make your hybrid downshift quicker.
====
Now to the procedures.
1. Lift up all 4 corners in the air and try best to make the vehicle parallel to the ground. This is because you’ll need the filler hole to check fluid level, which assumes the vehicle is NOT tilt.
This wasn’t easy — I only had a floor jack and 4 jack stands. Thankfully, the little 12V bottle jack I got from Costco was quite powerful and helped to lift up one side front so that my floor jack gained access to the front center jack point.
Note: ALWAYS double check the jack points before it is lifted by the tool. Try your best to align the jack centered at the jack point to prevent any slip.
2. Remove the large metal undercover using screwdrivers.
Note: there are 2 Philips screws which are notorious for seizing up or breaking the female threads inside. I had this problem with my 2017 Civic before. Therefore, try using something like WD40 silicone spray to help mitigate their rust and do NOT over tighten them!
3. Remove the drain plug. It is almost at the bottom and facing against the engine, i.e. facing the vehicle’s right side. It’s located quite to the front vs engine oil drain plug. There is only one plug which has 3/8” square female around that area so rest assured that you won’t unplug the wrong one.
The image shown below, filler plug is facing left while drain plug is facing right.
While draining old fluid out, remove the filler hole plug with 17mm socket. It is at the opposite side of the transmission case vs drain plug, and located at a higher position. It is facing the vehicle’s left side. There is a ‘v’ shape protruding beneath this plug which can help you find it.
4. Replace the washer for drain plug and tighten it to 36 lb ft.
Now fill the new ATF into the case. With a fluid pump, fluid can be pumped into the case through the filler hole. Alternatively, you can find a rubber cap from the top of transmission case when looking down into the engine bay, and fill with a long neck funnel.
No.12 is the rubber filler cap.
I suggest just dump all 3 qt into the case, and let excess fluid come out by itself. You don’t wanna save half bottle until next fluid change anyway.
5. Tighten the fill hole plug to 32 lb ft. As for the washer, it isn’t required to replace so just make your own decision. If you used the rubber hole, also cap it.
6. Install the metal undercover.
====
I feel that after ATF change my vehicle shows significant better shifting from cold start. In the past month when temperature dropped, it had sensable jerk at highway speeds after I pulled out in the morning. I see this always happened with the clutch engagement.
Therefore, in the future I plan to stick with 1 ATF change every 3 oil changes.
