Burned transmission oil

First, to ease your mind, it’s not the engine computer. The engine computer just receives inputs from the transmission control module — the transmission computer, in other words — and records the information that is put out as error codes, if there are errors generated. Here’s the thing about this, though, you noted twice that the transmission fluid smelled burned.

Transmission fluid normally runs hot because the transmission is a very warm unit in normal operation. It is not unusual for a transmission’s internal temperature to exceed 220-degrees F. Transmssion fluid, also, is an organic so it can burn if the transmission goes over temperature. That is primarily the reason you smelled the burned odor.

It is quite possible that your Honda’s transmission is now running correctly because the final fillup of transmission fluid corrected the problem that probably underlaid the whole issue. Believe it or not, it was likely a buildup of some sort of dirt deposit, possibly on a torque converter blade or on another input blade that was the initial issue for your transmission.

When you changed the transmission fluid the first time most recently, the deposit was finally exposed to a normal output from the torque converter. Over the brief time that the first fillup was in the transmission housing, the dirt was eaten away and then deposited on the transmission fluid. At the same time, because the transmission was working harder, generating higher temperatures, the fluid burned.

When you replaced the transmission fluid the second time, the remainder of the deposit likely was eaten away. Of course, there was a heat buildup again and you had to replace the transmission fluid again because it was burned.

Now that you have replaced the transmission fluid twice, it is quite likely that you have solved the problem. It all began with the wrong dirt in the wrong place.