Little help with cruise control

[DustenA]

Car is a non vanos 540i. So cable driven cruise control. I've pulled apart the motor, no teeth are missing. Issue has steadily gotten worse.

When setting the cruise it'll accelerate about 5mph above its current speed. Then settle into a sea saw motion of speed up and slow down. Holding the decrease button on the steering wheel will cause the car to accelerate.
On two occasions the car will accelerate once or twice then shut the cruise off, requiring a restart of the car.

Thoughts?

Video
https://youtu.be/pTSx8Nxw4fM

[StRaNgEdAyS]

Mt first guess is that you might have issues with the switches on the wheel, or the wiring in between?

Absinthe makes the tart grow fonder

[HoZy]

Cruise module, had this issue for couple years now. I've driven between Vic & Qld in aus couple times without using cruise. 2200km each way

I actually switched out the steering wheel to a non-cruise one simply for looks and removed the module because Mc'Fkit.

But Yeah, mine never see-sawd' it'd Enable, adjust speed couple times then never turn on or off again until ignition cycled. All teeth still there.

Never been a big fan of cruise myself.

Cheers
Mat

edit: To clarify, when I did my research the module disabled itself when it's reaction time is out of spec or something like that from memory as a safety feature & never logged any codes even via pasoft/bmwscanner/inpa.

[6spd540]

edit: To clarify, when I did my research the module disabled itself when it's reaction time is out of spec or something like that from memory as a safety feature & never logged any codes even via pasoft/bmwscanner/inpa.

I had a problem with my cable being bent to sharply and causing to much drag. When I went up hills I'd have to tap the gas pedal to help cruise maintain speed.

I could see something mechanical like the issue I had potentially causing all the OP's symptoms except the accelerating while pressing decelerate. For that one I'd think maybe the ribbon cable or module.


Sent from my Pixel XL using Tapatalk

[DustenA]

I had a problem with my cable being bent to sharply and causing to much drag. When I went up hills I'd have to tap the gas pedal to help cruise maintain speed.

I could see something mechanical like the issue I had potentially causing all the OP's symptoms except the accelerating while pressing decelerate. For that one I'd think maybe the ribbon cable or module.


Sent from my Pixel XL using Tapatalk

Cables are new.

[DustenA]

I'll pull apart the CC actuator one more time. IF its the module, do they require coding? I can't find many threads on the issue.

[DustenA]

Teeth are good. Cable moves butter smooth

[StRaNgEdAyS]

I lost my cruise control when I did my manual swap, most likely a result of changing the diff ratio. It turns on and the servo works, it just will not set a speed.
All the buttons and pedal switches function as required according to INPA, and there's no errors, and the GR2 module is correctly coded for a manual,so I guess it's got to do with it not seeing a close enough match between the engine revolutions and the wheel revolutions to its existing data table.
However that's not your issue.
You're getting no codes at all from the module, is that correct?
I wonder if it's worth taking a buddy for a drive to check the operation of the module and the wheel speed sensors with the laptop while driving to see if there's something that shows up then?

Absinthe makes the tart grow fonder

[DustenA]

Hmmm... I didn't check. Because I'm a doofus. I'll check tomorrow

[DustenA]

Pulled codes

"error in control monitoring"

The other didn't translate
"error in togglebit"

Cleared codes. Drove car. Cruise seemed normal. Returned home. No codes. I'll test it Friday night when I go to work. It's for sale now, so I'm going to only drive it when necessary.

[DustenA]

Drove it today. Cruise would engage, rapidly increase speed then shut off.
Code is "error in control monitoring"

Guess I need a new CC control module.

Any idea on what it takes to code one?

[StRaNgEdAyS]

As far as I know, you would use NCSexpert expert to code the module with the ZCS.
It's what tells the module what kind of ratios to expect and whether it's auto or manual.

Absinthe makes the tart grow fonder

[StRaNgEdAyS]

I'm not familiar enough with PAsoft to say if it would do the job unfortunately

Absinthe makes the tart grow fonder

[DustenA]

I only know how to use NCS expert. So I guess I will hunt for a CC module

[DustenA]

Used module installed. Coded. Cruise works. Spent less than $20

[StRaNgEdAyS]

Used module installed. Coded. Cruise works. Spent less than $20

Awesomeness

Absinthe makes the tart grow fonder