Cruise Control, Parking Sensors, and Original Stereo

[t1mm]

Hi there,

I've recently become the proud new owner of an E39 520i MSport. I'm in the process of doing a couple of jobs on the car, and I'd really like to get the cruise control and parking sensors sorted.

The seller told me that both the cruise control and parking sensors rely somewhat on the original stereo that came with the car. Unfortunately the stereo has since been changed to an aftermarket model - the previous owner wanted an aux connection and CD player.

Is this really the case? Did any of the E39 models come with a stereo which had an aux input? Is there any way to get cruise control and parking sensors working with an aftermarket stereo? Any advice would be greatly appreciated.

Thanks in advance!

[Keith Nguyen]

I don't believe the PO is correct. The cruise, audio and PDC run on separate components. What seems to be the problem?


--=Keith

[t1mm]

Thanks for your reply Keith Nguyen - interesting! I had my doubts to be honest. Neither the parking sensors nor the cruise control work at the moment. Nothing happens at all. Would you have any tips on where I could start the diagnosis?

Is the parking sensor sound wired directly into speakers, rather than through the stereo? It made no sense to me that the cruise control would go anywhere near the stereo.

[StRaNgEdAyS]

The PDC speaker is under the drivers dash, though the module is in the boot near the battery. The cruise control module. Is in the driver's kick panel on an LHD car I believe.. Your problems could be related to wiring being damaged there during the stereo install. It's possible that the PDC is working, just the speaker isn't functioning.
Replacing the radio head unit has no bearing on the function of either module

Sent from my G8141 using Tapatalk

[t1mm]

The PDC speaker is under the drivers dash, though the module is in the boot near the battery. The cruise control module. Is in the driver's kick panel on an LHD car I believe.. Your problems could be related to wiring being damaged there during the stereo install. It's possible that the PDC is working, just the speaker isn't functioning.
Replacing the radio head unit has no bearing on the function of either module

Sent from my G8141 using Tapatalk

Brilliant news! Thanks a million for your reply - I've got renewed hope

I've attached some photos of the area near the battery. Is the white module related to the PDC? I noticed that one connector's wires are cut, and wires instead appear to loop directly through to the lights. Is this unrelated? All lights function as normal.

Would hooking up a computer to the car tell me specifically which components had failed, or is it time to get the multimeter out?

Thanks again guys! Really appreciate the help

Images: https://www.dropbox.com/sh/gnqfc27vu...jZsRyD5Ja?dl=0

[StRaNgEdAyS]

INPA will let you know if the there are issues with either module for sure.

Sent from my G8141 using Tapatalk

[djb2]

I believe that the PDC depends on interactions with the MID ("radio", but really just a display and button interface). Perhaps steering wheel buttons for the cruise control require it as well.

It's pretty easy to add an interface that pretends to be a CD changer to get an audio input -- that's what the original owner should have done.

[amancuso]

I believe that the PDC depends on interactions with the MID ("radio", but really just a display and button interface). Perhaps steering wheel buttons for the cruise control require it as well.

It's pretty easy to add an interface that pretends to be a CD changer to get an audio input -- that's what the original owner should have done.

PDC doesn't go through the MID, but it does have a button on the centre switching panel. (Not sure if rear only PDC has the switch.)

[StRaNgEdAyS]

PDC doesn't go through the MID, but it does have a button on the centre switching panel. (Not sure if rear only PDC has the switch.)

Rear only doesn't, it is switched by reverse gear

Sent from my G8141 using Tapatalk

[geargrinder]

I'm not seeing any pitchers, is that me/my browser, or everybody?

OP - Some thoughts on your issues...

• PO sounds like a dope.
• PDC lives in the back by the battery indeed. You never know what morons might get up to. Easily pausible moron-logic could go "I hate the PDC anyway and I need power for my rear LED conversion aftermarket eBay module / neon-underlighting / electric-trunk-bong-illumination, so I chopped the PDC connector off and then probed for voltage and used whatever had some kind of volts there!". Does your PDC button on the dash light up when you push it, engine running, standing still? If not that's a place to start. The button is wired back to the PDC so if its dead, then probably the PDC module is dead. It is powered by K72 relay, so, your steering column and seat control would be out if that wasn't working... I'd focus on finding the module back by the battery, and seeing if its wires look at all molested, and trying to get the dash light to illuminate.
• This is a long-shot, but sound-wise, PDC has a coding option to change both front and rear sound sources to 'speaker' from 'gong'. I believe E39s default to use 'Gong' coding, which are the little dedicated noisemaker dinguses. Now that's the kind of obscure thing that might be different on a right hand drive car (BMW sometimes does weird exception stuff w/ the RHD cars)... but it SHOULD have the dedicated beeper device both front and rear. If coding is set to "speaker" on other hand then it may indeed send the signal to the radio? That's the kind of thing thats pretty undocumented, most likely not the problem, but there is a coding option for it.
• The cruise control is done via the DME (ECU) (as it is by almost all modern cars, and certainly all DBW / Drive by wire cars) only very early E39's had separate cruise modules. What is the cruise symptom? Do you get the cruise light to come on in the dash at all when you push the cruise on/off button? Or nothing whatsoever? First line of questioning would be if the steering wheel ("MFL") is communicating with the cluster and the DME at all. Otherwise you can use diagnostic software to interrogate the DME and see what conditions it is seeing, if the clutch or brake pedal switches are engaging, etc. See the text below from BMW...
• The one common denominator for the cruise and PDC could be the I-bus. The steering wheel buttons must be able to communicate on the I-bus to send signals to the cluster. If moron-PO got 'hacky' with the radio replacement, he might have screwed up the bus. An idiot might probe the I-bus while it was live and showing voltage and think "oh there's someplace I can pull power from!" See the bus map below for how the car wires all those things up. Although then you'd tend to see more things failing and not functioning...

PDC button wiring:
http://www.bmw-planet.net/diagrams/r...000015479.svgz

Steering wheel operation description...

Multi-function steering wheel (MFL) interface

With the aid of the multi-function steering wheel (MFL), the driver can operate various vehicle functions from the steering wheel. These functions include:

• Radio functions
• Telephone functions
• Cruise-control system functions

In addition to a high degree of comfort, the multifunction steering wheel also offers the driver increased safety as it is not necessary to take the hands off the steering wheel to operate various functions. The driver can implement the functions from the multifunction steering wheel without diverting attention from the traffic situation.
The response times to MFL keystrokes are so fast that no feedback from the vehicle is noticeable.
The signals for the cruise-control system are sent from the multi-function steering wheel to the engine control module where they are evaluated. There is no separate control module for the cruise-control system.
Operating the cruise-control system

A switch block for operation of the cruise-control system is located on the right-hand side of the steering wheel. Description of operating keys from top to bottom:

• Resume: The vehicle accelerates or decelerates from non-controlled operation to the driving speed last set and maintains this speed.
• Accelerate: The speed is increased by 1 km/h by briefly hitting this button. If pressed longer, the speed is increased until the button is released again. Cruise control is only switched on, however, if all switch-on conditions are fulfillled.
• Decelerate: The driving speed is reduced from the set speed by pressing the ”decelerate” button on the steering wheel. The speed is decreased by 1 km/h by briefly hitting this button. If pressed longer, the speed is decreased until the button is released again. However, it is not possible for the driving speed to drop below the minimum set speed.
  The deceleration function is terminated by a switch-off condition occurring:
• Off: switches off the cruise-control system. Switching the ignition lock to position 1 or 2 and actuating the main switch (I/O) places the cruise-control system on standby. The system preparation (arming) prevents inadvertent actuation of the MFL cruise-control system control elements. Cruise-control standby is indicated by an LED in the instrument cluster.

Switch-on conditions:

• ”Accelerate” button in neutral position before switching on cruise control.
• The minimum speed of 30 km/h must be exceeded.
• The brake pedal must be in rest position.
• The clutch pedal must be in rest position on vehicles with manual transmissiones.
• Drive stage ”2” to ”D” must be engaged on vehicles with automatic transmissiones.
• No switch-off condition must be active.

Faults detected in the cruise-control system are stored in the fault memory of the engine control module. These fault memory entries prevent any activation of the cruise-control system.
Cutout conditions:

• Deactivation via main switch
• Operating brake pedal
• Operating clutch pedal (manual transmission)
• Engaging drive stages ”P” or ”N” (automatic)
• Off: switches off the cruise-control system.

E39 buses:

[t1mm]

Thanks again for your replies everybody. I forgot to attach the photos to the last post, so here they are. Just to clarify, my car is rear-only sensors and doesn't have a PDC button on the center console.


I've put the car into reverse and listened to the sensors but neither of them produce a clicking sound. Going to try to ID the black box near the battery as definitely the PDC module, and if there are no wayward wires there, I'll try to diagnose it via INPA.


Thanks again guys!

Images: https://www.dropbox.com/sh/gnqfc27vu...jZsRyD5Ja?dl=0

[amancuso]

What the hell happened to your tail light wiring!?

[t1mm]

I've got no idea @amancuso. An investigation for another day I suppose. Does anyone see a PDC module in there?

I'm beginning to have my doubts - I just removed the two rear bumpers and although there are sensors in there, they're not connected to anything. No loose wires, nothing. I'm wondering if the PO replaced the original bumpers with these ones. Did any 2002 E39 models come without PDC?

[StRaNgEdAyS]

Yes, I've seen quite a few without PDC.
Give me a minute and I'll get a pic of the PDC module for you

Sent from my G8141 using Tapatalk

[StRaNgEdAyS]

It's the black module with PDC 12V written on it by the distribution block.

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[t1mm]

Thanks again Strangedays, that's really helpful. If you take a look at the following photo, it looks as though my car had a PDC once upon a time but it was removed:

https://www.dropbox.com/sh/gnqfc27vu...0+00.01.02.jpg

One of the bolts still has the nut on it, and the other is missing. Would bmwvin.com have returned PDC in the list of optional extras if it had been present from day one? A further two images, with the bmwvin results. (I've got no idea how accurate the results on the site are):

https://www.dropbox.com/s/e378emnqvc...22.21.png?dl=0
https://www.dropbox.com/s/9mx9lccrha...22.25.png?dl=0

[geargrinder]

Sometimes those nuts are not there from the factory if the module is missing.

I think its quite likely your car got a PDC bumper replacement.

I'll second that the taillight wiring is a mess too!

Are the taillights from a pre-facelift car maybe? I dunno nothing about what a pre-facelift taillight would look like in a facelift hole...

Maybe the car took a hit in the rear and then got a junkyard bumper and taillights?

- - - Updated - - -

Also - what kind of foolishness has been wired direct to your battery like that? The blue and brown wires running up into the trunk directly from the terminals? Terrible idea to have hot wires on the battery without being fused like that. Not to mention if you have to add wires to a european car please use brown for ground and NOT brown for power (ahh the power of a previous owner to astound with foolishness can never be underestimated!)

[t1mm]

Some photos of the rear of the car:

https://www.dropbox.com/s/w7t5zeotug...9e33.jpeg?dl=0
https://www.dropbox.com/s/s81b5ya0p4...69c5.jpeg?dl=0

Those wires are going to a cigarette lighter in the back of the car. I presume this is for powering a compressor or something along those lines. Agreed about the fuse though!

Right, thats one problem "solved" anyway. Thanks guys, shame it wasn't an easy fix >_<. Will look into retrofitting it, if I can find parts on the cheap.

Any tips on where to look to see if the cruise control parts were pulled out too?

Thanks again!

[geargrinder]

Tim -

Looks nice.

Yeah, here's what you do with that lighter-socket. Perfectly fine idea. Just not unfused like that.

Here's what you're going to do to take that socket from 'hacker mess' to 'sweet nearly factory mod'.

Pop the white cover off that box on the left with the green base. The clip parts are pretty self-explanatory.

Underneath there is some interesting stuff. There are some huge ass 'master fuses' right off the battery that are there to fuse the long-line wire runs to the front of the car. They never blow by the way, unless the car is cut in half or something.
But there should also be some unused fuses there. Fuses that are powered by the big red battery cable, but are not connected to anything. Should look like this:



Assuming you have some unused spots (you will), move the center-pole wire for that lighter socket (more on that in a minute) to one of the unused fuses of vaguely appropriate amperage (min 20amps if you want to supply a tire pump? might check the amperage rating of that socket tho'...).

You can even remove an unused fuse and fit one of a different amperage from the auto parts store if you like. If there is no nut on the far end - usually the case if it was unused from the factory - then its a standard metric nut from the hardware store (or you can steal some nuts from a junkyard car if you have such things...) easily sourced.

Then move the ground-pole wire for the lighter socket (again more on that in a minute) over to one of the nuts where the brown wires terminate in this picture on the far right. I'd probably use the smaller nut that the black plate style uses, and not the big ass stud that the actual battery ground goes to, just for connector size convenience.
https://www.dropbox.com/sh/gnqfc27vu...0+00.01.02.jpg

For both wires, you'll just crimp on a ring-terminal of the appropriate diameter:



Now. While you're at it, before doing the crimping and finishing... check the polarity of that lighter socket. The center should be positive and the outer part negative. If retard PO did it the oppo, then you risk the chance of some device you plug in making big sparks of it touches some part of the body of the car, or, worse, burning out some device with inadequate polarity protection inside. I'm very suspicious of the 'brown to power' color code. Even if it means making new wires, I'd make sure that if nothing else the brown wire is not used for actual power.

That'll be a much much sweeter and safer setup for the accessory socket.

- - - Updated - - -

Any tips on where to look to see if the cruise control parts were pulled out too?

Read my bits about cruise control.

On a motor of this (M54 engine running an MS43 computer) There really are no 'cruise control bits' per se.

The steering wheel buttons talk over a comms bus to the cluster and then directly to the DME/ECU (engine computer). The engine computer takes it from there, basically. THere are other dependencies, clutch/brake switches... but I already posted on that. Maybe you missed it.

[t1mm]

Hi geargrinder,


You're an absolute wealth of knowledge! Thanks a lot - I will definitely re-wire that accessory port. Cheers for the step by step guide; I really appreciate you taking the time.


I must excuse myself about your previous cruise control points - I was intent on fixing the PDC issue and moving onto cruise control afterwards, and must have overlooked your comments.

The cruise control is done via the DME (ECU) (as it is by almost all modern cars, and certainly all DBW / Drive by wire cars) only very early E39's had separate cruise modules. What is the cruise symptom? Do you get the cruise light to come on in the dash at all when you push the cruise on/off button? Or nothing whatsoever? First line of questioning would be if the steering wheel ("MFL") is communicating with the cluster and the DME at all. Otherwise you can use diagnostic software to interrogate the DME and see what conditions it is seeing, if the clutch or brake pedal switches are engaging, etc. See the text below from BMW...

In terms of a symptom - nothing happens at all. No light on the dash when the cruise on/off button is pressed.

The one common denominator for the cruise and PDC could be the I-bus. The steering wheel buttons must be able to communicate on the I-bus to send signals to the cluster. If moron-PO got 'hacky' with the radio replacement, he might have screwed up the bus. An idiot might probe the I-bus while it was live and showing voltage and think "oh there's someplace I can pull power from!" See the bus map below for how the car wires all those things up. Although then you'd tend to see more things failing and not functioning...

I now have an aftermarket stereo. CD changer looks like it was present at one point (cables with connectors loose in the left of the trunk). The radio, mk3 nav, bmbt are not present. PDC as previously discovered is not present. I'm unsure about DSP, LCM, and CMT 7000 Interface box. Does it sound reasonable that the ibus might have been damaged, and the PO sold off these extra components? Excuse my ignorance, but is the iBus a replaceable module, or rather a protocol over a particular wiring loom?


Perhaps its time to get some diagnostic software running, what do you reckon?

[geargrinder]

No I-bus is basically "a wire" if you will. A communication 'bus' is basically a 'wire' an a protocol to match. That diagram shows all the stuff that MIGHT be on a car.

LCM is the lighting module, you have that or you'd have NO LIGHTS!

All the other module abbreviations are various thing you have in the car. Most you definitely have, some is optional equipment.

The question I"m asking would be, if in hacking up the radio install, if he grounded or otherwise screwed with an iBus wire to the radio, whether he screwed up the steering wheels ability to communicate to the cluster.

Here's the wiring diagram for the steering wheel... I know its hard to read..

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

At the simplest - you might check Fuse 44 first. It also supplies the "MID" which I assume is missing... perhaps the guy shorted something and blew the MID fuse when he was screwing up the stereo install.

[t1mm]

The ASC button on the MID does turn on its respective light on the dashboard. Would this rule out fuse 44 being blown? I'll check the fuse when I get a chance, just in case. I think I'll probably have to wait until the weekend to do any major panel removal to inspect the wiring behind the stereo again properly though!

Thanks again for the help geargrinder

I just noticed that there are meant to be 4 rear PDC sensors on the bumper. My car only has two - the ones in the left and right black pieces of trim. If I installed a PDC system with only two sensors, would it work at all, or do all 4 need to be present?

[StRaNgEdAyS]

You really need the 4 sensors I think... Otherwise it will only detect at the corners

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[t1mm]

Right, well thats that well and truly put to bed then! Will report back with my cruise control findings. Thanks Strangedays

[geargrinder]

There might be coding things you can do, there's an option for "4 sensors" or "8 sensors". However that's I think the "rear only" or "front and rear" and I see no option for "2 sensors" so probably doesn't help!