Dual Clutch Transmission actuator current

KESSEEON

MEMBER
2016 KIA OPTIMA
1.7L
4 CYL
2WD
AUTOMATIC
110,000 MILES

I am having problems with my transmission. The car is acting up sometimes, but sometimes it works just fine. The problem occurs only with even gears, for example, changing gear from 1 to 2 or 3 to 4. The car slightly jerks sometimes, but sometimes it works just fine.

I know that the transmission adapts itself, but it seems like it is not able to adapt fully and some slippage/jerk is still there when changing to an even gear. I have an OBD device to read data from the ECU and TCU and one thing that I noticed is that clutch actuators are drawing different current when the car is in P gear, shouldn't they draw the same current as they are basically the same thing?

I got both clutches and flywheel changed 18k miles ago, so they should be in good condition, and we can rule them out. So, the logical thing to assume is that the clutch actuator is not working properly.

I also added pictures of the reading I got from the OBD port.

Images (Click to make bigger)

2 Replies

KASEKENNY

MECHANIC
18,907 POSTS

Yes. This could be the actuator, but we need to start with if there are codes. I am assuming that there are none since you didn't not any but did notice the different current draws for the actuators.

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

If there are no codes, then the current that you are noticing is an indicator of what the issue may be. This current is the amount of energy needed to shift the gears.

They are separated into odd and even because you have two shafts in the transmission. One has all the gears for the odd and the other is the even. So, it requires more current/energy to shift to the even gears hence this may be the cause of the shudder that you are feeling.

Does your scan tool show live data? If so, please monitor the amount of slip while it is shifting to even and odd gears. If they are different, then the actuator may be the issue.

I am attaching the process to replace it if it leads to this.

Images (Click to make bigger)