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      01-18-2020, 09:02 AM   #13
fmorelli's Avatar

Drives: Atacama Yellow 35i
Join Date: Mar 2016
Location: VA

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Originally Posted by RobbiZ4 View Post
No programming is required when you change a CTM. But you need the correct CTM depending on the number of external valves at your hydraulic pump (3 valves before 03/2012, 4 valves as of 03/2012)
Happy New Year, my friend. Good to see the resident Z4 top and electronics expert engaged

Since you brought up the hydraulic pump change - I know you have spent a lot of time understanding the whole top system. Do you have thoughts on the difference in pump? BMW has superseded the 3-valve pump with the 4-valve for pre-3/2012 cars. Older cars had a 3-pin connection to the 3-valve pump. Newer cars have a 4-pin connection to the newer 4-valve pump. BMW now supplies everyone the newer 4-valve pump and recommends connecting the 3-pin older car wiring to the 4-pin connector.

My guess is the 4th pin has to do with the 4th valve actuator. Obviously the wiring harness is different. Yet the CTM seems to be unchanged (p/n 61359281723)

As always, thanks for your insights.

2011 35i MT Atacama ... lots of bits. Full Íhlins TTX custom suspension. Build thread.
Build sheet. Currently finishing suspension, fuel, ignition system with Barry Battle @ 3DMMotorsport.