Cruise control problem - BMW Forum

rats1948 · 02-24-2009, 02:48 PM

Hi,
My E39 528i cruise control works fine for about 1 minute then disengages. Any one else had this problem? I have just purchased the car, previously I have owned Honda's which being Honda not may things went wrong. This Bmer has radio issues cruise issues etc. Dont get me wrong I still love it especially when I hit the go pedal and that buzz from the exhaust comes on song. I would appreciate any imputs. Thanks

marti5 · 02-25-2009, 09:59 AM

You will find this useful:

BMW E39 DIY (Do It Yourself)

Teh Prof · 02-25-2009, 10:23 AM

What year E39 do you have? If it's a 1997 or 1998, your cruise control unit could be bad. If it's 1999 or later, we need to ask some more questions, such as if your car is a manual.

rats1948 · 02-25-2009, 02:36 PM

Thanks marti5 great link. My 528i is a 1996 model the first of the E39, brought it cheap and slowly bringing it back to its former self. I carnt understand plebs who buy a good car and then let it deteriate arround them. I also have a radio problem which I see is another common fault. Thanks gin for your imputs. Cheers from down under Oz Ray

Teh Prof · 02-25-2009, 08:28 PM

My guess would be your cruise control module, or possibly the cable from the module to the throttle body.

rats1948 · 02-26-2009, 02:46 PM

Thanks again for your imputs everyone.

cuzzybro · 04-24-2009, 03:48 AM

I'm having a problem with the cruise control light disengaging too on my 98 540i auto.
Iv'e pulled apart the actuator and there appears to be nothing wrong inside, all cercuitry is fine. I tested one of the motors in the unit, it to is fine... maybe it's the other one?

I also see it could be the brake light switch, how will I test if this is faulty?
All lights are working correctly on the car.

can anyone help with this problem

marti5 · 04-24-2009, 05:40 AM

First off, see if the passenger side vanity mirror light is working in the sun visor if not its your ignition switch, seriously!

next,

From my experience...cruise control problems are the first indicator of an electrical problem. It seems to be extremely sensitive to low voltage.

First thing...clean your battery terminals. Make sure the connections are good and tight. Find where the negative battery terminal mounts to the chassis and use sandpaper or plumbers cloth to clean up that connection. Then, go under the hood. On the passenger side, toward the front, you'll see some black plastic connectors with a bunch of brown wires. Unbolt the harnesses from the chassis and rough-up the connections with sandpaper to provide a great ground for the components that the wires serve. Lastly, you'll find the ground/chassis connection for the DME computer just beneath the passenger side cabin air filter. Take it off, rough up the connections and tighten her down.

Now see if your cruise works any better.

If it does not...check the voltage on the battery...it may be time for a new one. Next step would be to check voltage with it running to determine if the alternator is on it's way out.

Good luck.

cuzzybro · 04-24-2009, 06:12 AM

My drivers side doesn't work could this be a problem?

Thanks very much I'll go thru your suggestions tomorrow.

marti5 · 04-24-2009, 10:31 AM

Could well be as you are on the other side of the car, that would make it here the passenger side, so I would say its your ignition switch, which is not the barrel its self but is a switch at the end of the barrel.If you send me the last 7 digits of your VIN I will send you a diagram or you can look for it yourself at :

RealOEM.com Online BMW Parts Catalog

caryabhi12 · 04-24-2009, 02:47 PM

It is nice information.

cuzzybro · 04-25-2009, 01:22 AM

Were actually right hand drive here in Oz.
could this still be the problem or is it specific to passenger side vanity lights?

I found the switch on pelican parts for $56. might just have to try it and see if it fixes the prob. It's so much cheaper than replacing the actuator like my mechanic said, his price would be over $700. From pelican parts I think they are half that but $56 is much better

I'm just about to run thru the list of things you said to check.

Thanks again

marti5 · 04-25-2009, 03:11 AM

Oh yea ! right hand side, I must have had a brain lapse for a second!!, anyway the last one I dealt with the passenger mirror didn't work, when we changed the switch the cruise worked and the mirror light came one, this was on a 7 series so maybe its the other way around on a 5 ??? worth a try and they do go sometime so at least you will know that's not the problem and wont be for a long time to come.