M52TUB25 Cruise Control Retrofit Challenges

NZ00Z3

Zorg Guru (IV)
Supporter
New Zealand Zeds
Joined
Dec 9, 2014
Points
158
Location
Timaru, New Zealand
Model of Z
3.0L, 2.8L, 2.0L Z3 Roadsters
Thanks for you reply and information.

Today's revelation is that there should be two clutch switches in your car:
- for the fully depressed clutch in the start function. drawing 1240.0-00, Brown/Black control wire
- for the clutch depressed signal in the CC. drawing 6571.0-03, Blue/Brown control wire

Do you have both switches installed?

Did you change the correct switch?
 
Last edited:

NZ00Z3

Zorg Guru (IV)
Supporter
New Zealand Zeds
Joined
Dec 9, 2014
Points
158
Location
Timaru, New Zealand
Model of Z
3.0L, 2.8L, 2.0L Z3 Roadsters
My knowledge and experience with NCS expert/dummy is very limited. I tend to leave them alone as they have strong powers and my lack of knowledge could lead to stuff ups.
 

staggerwing17

Dedicated Member
Supporter
American Zeds
Joined
Aug 4, 2019
Points
35
Location
Gilroy, CA
Model of Z
3
Well, Mr. Wall, I am humbly and forever in your debt. I spent the afternoon trying to understand where the second switch might be, if it even existed for this car. So I followed your wiring diagrams and compared wire colors to the 3 pole switch I had installed. As you surmised, they did not match, meaning the switch in the upper far left of pedal bay to the left of the pedal is NOT the clutch switch. It is the Starter Immobilization Switch you discovered in the diagrams. So what about the clutch switch then? Guess what? NO Clutch Switch in the car.

I looked more closely at the box on the electrical diagram and wondered what each of the numbers meant. There is a 5 digit number X90089 (sorry not at home so may not be the correct number) that refers to a location diagram at the back of the troubleshooting manual. It showed the clutch switch to the RIGHT of the pedal. So from left to right as you look in the footwell is the Starter Immobilization Switch, the clutch pedal, the clutch switch, the brake pedal and then the brake switch. And indeed upon looking in my particular footwell, there was an opening in the bracket for the missing switch. I then dug around to see if there was a 2 wire plug up in the wiring loom. A difficult fine but it was there.

I had a spare 2 pole brake switch from gathering original cruise control parts and it not only fit the opening but also the plug! So I hooked up INPA, mounted the switch, adjusted the plunger and released the clutch pedal. OPEN circle in the Clutch Switch Input! Unhooked INPA and took the car for a drive - or should I say cruise? Just fantastic! And it is a very nice cruise control as well.

I am beyond thrilled Murray! And as a big bonus, the issue with the revs hanging when the clutch pedal is depressed is totally gone. I now need to re-learn how to drive this awesome car. Thank you sir!!
 

NZ00Z3

Zorg Guru (IV)
Supporter
New Zealand Zeds
Joined
Dec 9, 2014
Points
158
Location
Timaru, New Zealand
Model of Z
3.0L, 2.8L, 2.0L Z3 Roadsters
What an excellent result, well done. Its a great joy when you finally solve the problem.

When I have installed cruise control into manual Z3's previously, the clutch switch was already installed, but none of them where from the USA market, which we now know is different.

I was beginning to worry that the DME was the problem, so I'm very relieved to hear that you have the CC working.

Time for you to get out and enjoy the settled autumn weather with a good cruise or two.

Regards

Murray
 
Last edited:

Nodzed

Zorg Expert (II)
Supporter
British Zeds
M Power
Joined
Feb 18, 2016
Points
231
Location
Forest of Dean, Gloucestershire, England
Model of Z
Z3M Imola and Z4 (e89)
Interesting read (though most of it went over my head, I like to use spanners and hammers not electronics) excellent job both in getting it sorted. :thumbsup:
 

staggerwing17

Dedicated Member
Supporter
American Zeds
Joined
Aug 4, 2019
Points
35
Location
Gilroy, CA
Model of Z
3
Just to follow up and wrap up this thread, I took a few pictures of the components mentioned in the thread. Keep in mind these are images of a USA car with fly-by-wire cruise control (despite having an accelerator cable, a M52TU characteristic). The car is a 1999 Z3 with 5sp manual. Again, thanks to @Murray Wall for his help!

Cruise Wrapup 01.png


Cruise Wrapup 02.png


Cruise Wrapup 03.png


Cruise Wrapup 04.png


Cruise Wrapup 05.png
 

staggerwing17

Dedicated Member
Supporter
American Zeds
Joined
Aug 4, 2019
Points
35
Location
Gilroy, CA
Model of Z
3
Interesting read (though most of it went over my head, I like to use spanners and hammers not electronics) excellent job both in getting it sorted. :thumbsup:
Hey! I had to use a 10mm socket and ratchet handle! And a screwdriver!!
 

t-tony

The Legend
Deceased
Supporter
#ZedShed
Joined
Dec 31, 2013
Points
226
Location
Torksey Lock,Lincoln, England
Model of Z
E89 Z4 23i Auto
Spam?
 

GazHyde

Administrator
Administrator
Global Moderator
M Power
Joined
Dec 2, 2011
Points
226
Location
Berkshire
Model of Z
Z4 MR
Top