BMW M5 Forum and M6 Forums banner

1 - 20 of 27 Posts

·
Registered
Joined
·
171 Posts
Discussion Starter #1
I might retrofit this system.

1.)Does it work well or do you have any issues with it it?
2.) What do you like or dis-like about it?
2.) Would you miss it if you didn't have it?

Any general feedback appreciated.

Thanks.
 

·
Registered
Joined
·
3,863 Posts
I might retrofit this system.

1.)Does it work well or do you have any issues with it it?
2.) What do you like or dis-like about it?
2.) Would you miss it if you didn't have it?

Any general feedback appreciated.

Thanks.
Insofar as the tire warning system on the E39 M5 is concerned,

1) I have had no issues with it and it has worked fine for me usually giving me a warning when the problem tire is not more than 3 psi down from the rest.

2) I like that it does not require tire-pressure monitors mounted on each wheel. It uses permanently mounted equipment (ABS sensors) that do not need to be switched from wheel to wheel. ABS sensors also seem to be more robust than the typical tire pressure monitor and are cheaper to boot.

3) I like knowing it is there and that since it uses the ABS wheel speed sensors that a failure in that sensor will be reported by several diagnostice systems other than just the tire monitor system.

I think it is a reliable and very simple means of monitoring tire pressure. I have seen some pretty slick Hella TPMS installs, though, and may go that route someday. I would retain the factory system, however.
 

·
Registered
Joined
·
2,156 Posts
Retrofit Vs. a new TMPS?

I'd go with a new one as it might cost more to retrofit + you'd get more accurate info(e.g. which tire is low on pressure)...
 

·
Registered
Joined
·
3,600 Posts
fyi, copied and pasted from a pdf I found:

The Tire Pressure Warning System (RDW) is being introduced for the US market on the new
E39 M5. RDW is the German acronym for “Reifen Druck Warnen” and it follows the tire
pressure control system (RDC) that has been in use in other markets for several years. The
RDW and RDC systems will eventually be linked to the run flat tires as a means of warning
the driver of pressure losses in the tires.
Experience has shown that the majority of owners are unaware that the owner’s manual
recommends that the inflation pressure be checked at 14 day intervals. The RDW system
will aid in this by warning the driver of pressure losses in one or more of the tires.
Consequences of incorrect inflation pressures result in:
• Increased tire wear
• Reduced service life of the tires
• Impaired vehicle handling
• Increased risk of punctures due to worn tread
15
Overview
The RDW is a simple system that will warn the driver of pressure losses in one or more of
the tires through the “Check Control” display.
The system measures the wheel speeds of all four tires and compares the speed of the
diagonal wheels for the average speed. A rolling circumference value is calculated from the
wheel speeds and this value is stored in the control module.
In the event of pressure loss, the rolling circumference of the affected tire is reduced . With
this, the wheel speed of the tire increases and the control module will detect the change
and post the warning in the Check Control matrix display.
An additional acoustical warning is sounded if the pressure loss is greater than 40%.

The tire pressure warning system is switched “ON” every time the ignition is switched “ON”
and it can be switched OFF with the button on the lower dash to the right of the steering
column.
NOTE: The system can only react to the pressures in the tires when the
system is initialized, it cannot check for the correct inflation pressure.

System Components
The tire pressure warning system consists of the following components:
DSC III Control Module / Wheel Speed Sensor
The four wheel speed sensor inputs are processed by the DSC control module and four
dedicated square wave output signals are provided to the RDW control module for its processing
functions.
RDW Control Module
The RDW control module is located behind the glove box in the control module carrier. in
addition to the four wheel speed signals, the module receives power (KL 15), ground (KL
31) and a ground signal input from the set/push button switch in the console.
The control module is connected to the K-Bus for:
• Output display in the check control matrix
• Diagnostic communication through the instrument cluster with the DISplus tester or
MoDiC
The control module processes the wheel speed signals and stores rolling circumference
values for determining pressure losses in one or more tires.
17
Set/Push Button Switch
The push button (with tire failure symbol) is mounted below the instrument cluster to the
right of the steering wheel. The push button is used to carry out the following functions:
• Initialization of the system - after changing inflation pressures or tires.
• Switching the RDW system OFF - After switching the ignition switch ON, briefly press
the button “TIRE MONITORING INACTIVE” will be displayed in the matrix.
• Self diagnosis of the control module (only for manufacturing purposes) - however if the
push button is pressed and held while switching the ignition ON, “TIRE PRESSURE
INACTIVE” will be displayed in the matrix.
!
18
Check Control Display
The check control display is used to show the operating status of the RDW system. The
displays are as follows:
• “TIRE PRESSURE FAILURE” - (with an acoustic warning) this display will remain active
until the ignition is switched OFF.
• “TIRE PRESSURE SET” - Will be displayed when the system is put into
the initialization mode.
• “TIRE MONITORING INACTIVE” - Will be displayed when the system is manually
switched OFF or there is a system fault.
19
Initialization
The RDW system must be initialized to allow the control module to adopt the wheel speed
signals and set the rolling circumferences in its memory. Initialization must be carried out
when:
• Tire inflation pressures are changed.
• New tires are installed.
• The control module or wheel speed sensors are changed.
The initialization process is started by pressing the push button >4 seconds (Tire Pressure
Set will be displayed in the matrix). The system is now in the learn mode and after driving
off, the control module will start to store the values for the rolling circumferences of the tires
based on the road speed.
For leakage detection, three different speed ranges are taken into account and must be
recognized by the control module to complete a full initialization process. The control module
must receive useable speed signals for a cumulative total of 4 to 15 minutes depending
on the speed range.
Once a speed range is set, the control module will then monitor that speed range for and
pressure losses. The system can only display a pressure loss warning, it can not display the
exact tire with the pressure loss. All tires need to be checked when the warning is displayed
in the matrix.
NOTE: Not all speed ranges need be set for the system to function properly.
20
Initialization
Under certain driving conditions the control module will not evaluate the wheel speed sensors
as false warnings could be triggered. These conditions include:
• Initialization in a speed range that has not been complete
• During rapid acceleration
• Severe (heavy) braking
• High speed cornering
• Road speeds < 7MPH
• High slip differentials between individual wheels
No Warning Conditions
The system can only detect pressure differences between tires, it can not measure absolute
pressure. The system can not detect the following:
• Natural diffusion that occurs on all tires equally
• A tire blow out
• Pressure loss at the rear axle at speeds > 90 MPH
21
Diagnosis
The RDW is fully diagnosable via the K-bus interface using the DISplus tester or MoDiC.
Information included in the diagnosis includes:
• How often and at what speed the fault occurred

• If the initialization has been carried out for all speed ranges

Note: this pdf has a lot more techincal info about the car as a whole, so if you have never read this information before, PM me and I can send you the entire pdf.

edit:I'll attach the file.

Scott
 

Attachments

·
Registered
Joined
·
52 Posts
Mine has only alerted me once, and I did have a slow leak, running at about 10psi when I pulled over to fill up. I've also swapped winter tires for a few seasons and was glad I didn't need expensive monitors in each wheel. I have no problem with the system - it works for me.
 

·
Registered
Joined
·
4,670 Posts
I have the Hella that Josiah referred to.

I love it.

Tells me what the pressure/temp is at start up and on demand. Its real time live info for my tires.

IMHO the stock system isnt near as robust or reliable as an aftermarket option.

Aftermarket will cost you less and probably be quite easier to install.
 

·
Registered
Joined
·
906 Posts
Has done it's job quite admirably

On three occasions since my ownership, this system has alerted me to loss of pressure. All of them
were dead-on with regard to accuracy, saving damage to the affected tire. I can't help but be very
pleased with it's overall performance, especially from a system designed well over ten years ago.

Regards,
Alan
 

·
Registered
Joined
·
171 Posts
Discussion Starter #11
Thanks again for all the great feedback. The only thing I don't like about the Hella is I don't like the look of aftermarket gadgets and prefer the clean factory look.
 

·
Registered
Joined
·
239 Posts
I picked up my M5 recently and I see mine has that button, however when I press it is says it is inactivated. How do I activate it if I even can? thanks!
 

·
Registered
Joined
·
239 Posts
I might retrofit this system.

1.)Does it work well or do you have any issues with it it?
2.) What do you like or dis-like about it?
2.) Would you miss it if you didn't have it?

Any general feedback appreciated.

Thanks.
Thanks sidney you helped teach me something about my "new" M5!



I picked up my M5 recently and I see mine has that button, however when I press it is says it is inactivated. How do I activate it if I even can? thanks!
This thread got me searching and I answered my own question with the help of M5 Board (love this place!)

http://www.m5board.com/vbulletin/e39-m5-e52-z8-discussion/60082-set-tire-pressure-feature.html
 

·
Registered
Joined
·
4,670 Posts

·
Registered
Joined
·
4,670 Posts
Thanks again for all the great feedback. The only thing I don't like about the Hella is I don't like the look of aftermarket gadgets and prefer the clean factory look.

I dunno...

Take a look at where I mounted mine:





Seems pretty clean to me?

I know Whatheheck was going to try to mount his in the cigarette tray. He ended up selling his car before he got around to modding the unit so it would fit flush so the door would close.

Granted, its not stock STOCK looking but Im willing to sacrifice some aesthetics for the increase in safety and coverage.
 

·
Registered
Joined
·
171 Posts
Discussion Starter #16
Yeah looks pretty good Hdhntr23. Thats a good spot. Did yours not have the factory system? I wonder if one could integrate that somehow in the trim piece where you have it to sit flush and then trim it out to make it look even better. But that does look good.
 

·
Registered
Joined
·
4,670 Posts
Yeah looks pretty good Hdhntr23. Thats a good spot. Did yours not have the factory system? I wonder if one could integrate that somehow in the trim piece where you have it to sit flush and then trim it out to make it look even better. But that does look good.

Yes, I still have the factory system, the button that goes with it is now behind that trim piece you see. I routed the wire for the Hella thru that button hole where the factory OEM switch was mounted.
 

·
Registered
Joined
·
171 Posts
Discussion Starter #18
Yes, I still have the factory system, the button that goes with it is now behind that trim piece you see. I routed the wire for the Hella thru that button hole where the factory OEM switch was mounted.
You want to sell me your factory system? Would need the switch and modual and any of the wires if you can fish them out.
 

·
Registered
Joined
·
12,398 Posts
Factory system is inferior to the pressure sensing system. Given a choice there is ZERO doubt as to which I would choose. The factory system is fairly insensitive and slow to react.

You car is not an M5... why does it 'need' a factory TPMS??? Go with technical quality, not looks.

Just my little opinion

A
 

·
Registered
Joined
·
4,670 Posts
What I would charge you for the system would probably more than what you can get the Hella for. What I would charge you would be less than buying the system new from your dealer.

I say go with the Hella.
 
1 - 20 of 27 Posts
About this Discussion
26 Replies
13 Participants
E55AMG2
BMW M5 Forum and M6 Forums
M5Board is the best forum community for information on the BMW M5 E60 (V-10), E39 (V-8), E34 (straight 6), E28, F90 and F10. Discuss performance, specs, reviews and more!
Full Forum Listing
Top