BMW Throttle Actuator Repair - Gear Kit For M3 M5 M6

[@kb4777]

How big was that drill vice you used please ?

[@cellstheory4473]

How would I know if it’s the circuit board and the gears both?

[@storchcebek1702]

Brother thanks for the video ! Where did you buy the gears? Please plug me

[@mista5796]

Obviously the plastic gears get worn over time… but what is the reason for the actuators ‘failing’? Why do they throw the engine code 2b15/2b16 and cause the car to go into limp mode?

[@damascus-ut1ee]

When the gears wear, this causes a movement back on the throttle linkage causing the ITB's (independent throttle bodies) to slightly open or close from where they are supposed to be. I'm not 100% this is how it works, but this is how I imagine it: The DME monitors the actuator's positions based on pedal throttle position, RPM, transmission gear, etc. So when the DME looks for a certain value (say 0.80 volts reference) from the throttle actuator circuit when TPS (throttle position sensor, or other fore-mentioned parameter(s)) is at 30%, and sees its at an incorrect 0.70 volts (due to gear slop) it throws a code. Worn gears also may cause an oscillation affect where the gears go back and forth (because there is material in the teeth missing). If the DME senses values swinging (say between 0.80 volts and 0.70 volts) multiple times per second, it realizes there is an issue where the throttle blades are not being held in the correct position for a given amount of time and throws a code. I'm also told the electronic boards go bad inside these units, which could send wrong values to the DME, and consequently not opening/closing the throttle actuator correctly or holding it at the correct position. Any codes being thrown probably put it into a safe mapping or limp mode, which is a precaution to save the engine from running lean/rich.

[@mista5796]

@@damascus-ut1ee the bank 1 throttle actuator (on my e60 m5) was playing up and causing the limp mode fault. I removed both actuators replaced the plastic gears inside. The gears were slightly worn, but it didn’t fix the issue. Evidently the circuit board has failed somewhere in the bank 1 actuator. I’ve now removed both actuators again and have bought two newly rebuilt/ refurbished ones. Hopefully this fixes the issue. My feeling is the principle reason the actuators fail is due to faulty circuit boards. Replacing the gears alone is insufficient. When the actuators start playing up then almost certainly the circuit boards are failing as well.

[@damascus-ut1ee]

@@mista5796 Yes it seems whether the gears fail, or the circuit fails, the DME does not know the difference. It's looking for some value and/or voltage mapping, so when it doesn't meet those values it recognizes the throttle blades as "out of position" and throws a code and/or goes into limp mode. I hope your new parts fix your issue