Cruise Control, Parking Sensors, and Original Stereo

[Keith Nguyen]

The system will error out with two sensors. You need a set of four on either end.


--=Keith

[t1mm]

Thanks Keith. I've put that dream to bed at this point. Will report back with any cruise control findings. Cheers

[kgeorge81980]

Im having same issue with the cruise control. Nothing when buttons are pressed in correct order. No indicator light. Instead of dumb ass po i purchased a litteral barn buy a d the rats seemed to love the wiring under the hood. I reconnected everything i could find.

[t1mm]

Me again!

I bought a diagnostic cable to run a few tests on the cruise control based on geargrinder's suggestion. I can't communicate with the MFL via INPA though, unfortunately. The facts:

- Cruise control won't turn on.
- The car was originally specced with sport MFSW ("S710A M sports steering wheel, multifunction").
- An e46 MFSW is fitted to the car. The airbag doesn't sit perfectly flush in it. Based on what I've read though, this wheel should be plug and play.
- None of the buttons on the wheel are not lighting up.
- No communication via INPA.

Based on this, I think the logical next steps are to:

- Check all possible related fuses.
- Remove steering wheel and check its actually plugged into the slipring connectors.

Failing this, I've read that the ignition switch can sometimes be at fault, but as there are no other electrical issues I'm inclined to think this should be fine.

If anyone has any other tips or tests I could try out I'd really appreciate it

[777300ER]

Wow, yeah. I'm guessing that airbag isn't seated correctly or the wheel isn't plugged all the way in. Does the airbag light go on then turn off when you start the car?

[t1mm]

I'm 99% sure it does - will check shortly. Does this mean that its hooked up correctly?

[t1mm]

I got a bit sidetracked on the car, replacing the oil sump gasket, CCV, oil filter housing gasket, leaky radiator hoses, and all sorts of other things. I've learned a lot from buying this car - especially about the pre-purchase inspection process...

It hasn't beaten me just yet though. I've decided to pick up the old thread of fixing the cruise control function:

- Found a 20amp fuse in fuse position 44, which should have 5a. I replaced the fuse.
- Replaced the buttons in the steering wheel with a set of known working buttons.
- Clutch pedal switch can be observed in both on and off position via INPA.
- Brake pedal switch can be observed in both on and off position via INPA.

None of the steering wheel lights are illuminated. Cruise I/O button does not illuminate anything on the dash.

I most recently took a good look behind the stereo, and it pains me to reveal the horror show I found back there:

https://www.dropbox.com/sh/t82y94yij..._2cu3TUma?dl=0

At this point, I am feeling a bit beaten - I think this is probably a bit beyond my level. Should the wiring coming from the ECU going to the MFSW be part of this loom encased in the black flexible material? The PO was an obviously an absolute butcher...

[geargrinder]

Glad you got cable/diag up and running. You'll really appreciate that over the long term and start to wonder why everybody who DIY's doesn't have that...

Cruise buttons can be tested in INPA too - with a DBW car it should be in the DME 'Status' values.

Wondering if the E46 vs E39 MFL systems work signficantly differently. Maybe I'll have a quick look at the WDS and see if anything jumps out.

[geargrinder]

Nope. Just looked and the E46 wheel should be fine, pin-wise.

This should help - sorry for the text size but that's how that website works unless you jump through hoops to run an obsolete browser and version of java which is a huge PITA.

http://www.bmw-planet.net/diagrams/r...000011038.svgz

Coming off the coil spring (the 'back-side' / car-side... not the wheel-side), these are the critical pins for the MFL module:

8 - Yellow w/ black stripe - Should go to DME pin 27 of connector X60004.
9 - White w/ green and yellow - should go to Pin 8 of cluster connector if you have high cluster, or pin 20 if you have low cluster
10 - Purple w/ brown - Fuse 44

The fact that you don't get lights seems to suggest you're not even getting power, so, the fuse connection would be the first to check into.

That fuse IS supplied by the ignition switch, so, if that was bad, maybe it could be causing trouble.

HOWEVER... this seems more likely: That fuse also supplies the MID which of course must have been replaced with this aftermarket stereo mess. Since moron PO made such a mess of the stereo possibly he shorted out the that wire and blew the fuse, or, maybe he cut the other line off of fuse F44 so its not connected to the wheel anymore or something amazingly stupid like that.

The diagram shows it goes fuse -> splice X10022 -> coil spring. So if the fuse is OK but the power isn't coming through to the clock spring, you could also check that splice location which is here, in the module rack behind the glove box. All the wires are purple/brown so it should be not too hard to ID.
http://www.bmw-planet.net/diagrams/r...39_EX1650A.htm

From that fuse it should be a straight run to the clock spring connector.

[t1mm]

Thanks again geargrinder, I appreciate the help! I'll be taking a further dive into this over the next couple of days and will be sure to report back Cheers!

[t1mm]

Pulled apart the glovebox area today to take a closer look. No wires at all at Fuse 44. No loose wires hanging around the area. Starting to look like a retrofit project if anything!


When I did a lookup on my car's VIN, it listed "S710A M sports steering wheel, multifunction". Nothing specifically listed for cruise control.


If the car never had cruise control, and the original steering wheel only had buttons for the stereo, wouldn't there still be a wire at Fuse44 to supply power to them?