E46 BMW Social Directory E46 FAQ 3-Series Discussion Forums BMW Photo Gallery BMW 3-Series Technical Information E46 Fanatics - The Ultimate BMW Resource BMW Vendors General E46 Forum The Tire Rack's Tire Wheel Forum Forced Induction Forum The Off-Topic The E46 BMW Showroom For Sale, For Trade or Wanting to Buy

Welcome to the E46Fanatics forums. E46Fanatics is the premiere website for BMW 3 series owners around the world with interactive forums, a geographical enthusiast directory, photo galleries, and technical information for BMW enthusiasts.

You are currently viewing our boards as a guest which gives you limited access to view most discussions and access our other features. By joining our free community you will have access to post topics, communicate privately with other members (PM), respond to polls, upload content and access many other special features. Registration is fast, simple and absolutely free so please, join our community today!

If you have any problems with the registration process or your account login, please contact contact us.

Go Back   E46Fanatics > E46 BMW > General E46 Forum

General E46 Forum
This is the place to get answers, opinions and everything you need related to your E46 (sedan, coupe, convertible and wagon) BMW!

Reply
 
Thread Tools Search this Thread Rating: Thread Rating: 1 votes, 5.00 average. Display Modes
Old 11-17-2010, 12:19 PM   #21
MachRc
E46Fanatic
 
MachRc's Avatar
 
Join Date: Sep 2002
Location: City of Angels
Posts: 6,481
My Ride: 2003 Technik S1 M3
its 180 for diagnostic fee..
__________________

"We've come a long long way together. Through the hard times and the good.
I have to celebrate you baby,.. I have to praise you like I should.."
MachRc is online now   Reply With Quote
Old 11-19-2010, 08:51 PM   #22
Dev46E
Registered User
 
Join Date: Nov 2010
Location: Knoxville,tn
Posts: 4
My Ride: 2001 325i
Hey guys,
Let me know Ive got a simialar prob,,car sat for 10 months,,,Long story short would idle,,found cracks in the all the tubes and replaced the ccv and tubes,,,,Idles perfect now but in 5th(auto) on the hwy idle bounces up and down, and can feel the car not right,,,Driving me nuts,,,only code was po444 on the cheap machines,,,but looking around on here,Hell it might be the Disa valve,,,a vacuum leak(again),,o2 sensor,cat,, dmu,, now read may be a tranny prob...But if i put my cruise on it kinda holds steady,,, I may take to dealer just to see what codes they pull up,,,but gotta save up the 135 hook up price,,,, tired of pulling my hair out,,,and just cant keep throwing parts at it,,,
Dev46E is offline   Reply With Quote
Old 11-21-2010, 02:25 PM   #23
TxTorqueMade
Registered User
 
Join Date: Apr 2008
Location: Dallas, TX
Posts: 1,364
My Ride: 330i
Send a message via Yahoo to TxTorqueMade
Quote:
Originally Posted by SweetBMW View Post
Might be your accelerator pedal module-... BMW SI bulletin says that customers have complained about this exactly problem with a delay in throttle response. This was resolved with a new module at the cost of 150USD

Yup. Id say this could be it.
__________________
BMW e30 Bling
TxTorqueMade is offline   Reply With Quote
Old 11-21-2010, 03:47 PM   #24
AMG Killer
Registered User
 
Join Date: Jun 2008
Location: Rancho Penasquitos/SD
Posts: 244
My Ride: M3 Lambo killer
well it wouldnt be the accelerator module rather but the poteniometer that measures the ressistance and sends a signal to the throttlebody's
__________________
AMG Killer is offline   Reply With Quote
Old 11-22-2010, 03:08 AM   #25
Fr3nch
Registered User
 
Join Date: Oct 2010
Location: SW
Posts: 26
My Ride: :/
Quote:
Originally Posted by AMG Killer View Post
well it wouldnt be the accelerator module rather but the poteniometer that measures the ressistance and sends a signal to the throttlebody's
Hey now, careful with those big words, haha. Bently's says there are two pots in the module and Ill be checking them both over Thanksgiving. Do you know what the range and tolerance for the pots are? Bently's doesn't have that info. Also is there a good resource for more advanced technical info like i/o voltages and resistances of different sensors on this car?

While this seems like this is a good place to start, I am still not very convinced this is the problem. it doesn't occur when the car is not under load, i.e. the car is in neutral or the clutch is pushed in. I would think if it were something in the accelerator pedal, the problem would occur 100% of the time regardless of weather the clutch was in or not. Are there other potentiometer type sensors in the gear box somewhere?

I also want to clarify that this is not the Stick-slip effect explained here:

http://www.meeknet.co.uk/E38/E38_Sti...ttle_Pedal.pdf
Fr3nch is offline   Reply With Quote
Old 12-22-2010, 06:35 PM   #26
Fr3nch
Registered User
 
Join Date: Oct 2010
Location: SW
Posts: 26
My Ride: :/
Update

Update:

I finally got around to checking out the accelerator pedal module. Apparently there are two potentiometers behind the pedal that detect pedal position. I took a multimeter and measured the resistances between the six different pins on the module. I was able to find what pins go to which pot and determined that the two pots are not connected. This is confirmed by the wiring diagram in Bentleys.

The thing that has me totally stumped is that the resistances didn't change when the pedal was pressed. This is completely perplexing to me, since if the resistances don't change when the pedal is moved, the computer should not be getting any signal at all, yet the car revs fine (except for the original issue). Any input on the would be helpful. Thanks.

Here are the measured resistances:
Pot 1: pin 1-4 = 57 ohms, pin 4-5 = 427 ohms, pin 1-5 = 477 ohms
Pot 2: pin 2-6 = 57 ohms, pin 3-6 = 427 ohms, pin 2-3 = 477 ohms

Also, I drove the car 8 hours (at the speed limit) in heavy rain a week ago. My destination was 3000 ft lower in elevation than home. After this trip, the response issue was much better, and I had more power across. The problem is slowly coming back as I am driving around town.

Again these did not change when the pedal was pressed

Last edited by Fr3nch; 12-22-2010 at 06:46 PM.
Fr3nch is offline   Reply With Quote
Old 12-23-2010, 12:56 AM   #27
cyberkaa
Registered User
 
Join Date: Jul 2008
Location: Sunnyvale, CA <-- Ithaca, NY <-- dirty jerz (201) Useful Posts: 25
Posts: 136,481
My Ride: E46 332i,M3;E30 325i
Send a message via ICQ to cyberkaa Send a message via AIM to cyberkaa Send a message via MSN to cyberkaa Send a message via Yahoo to cyberkaa
Hmm, your car does seem to have the symptoms associated with a bad accelerator pedal. The DME will slow responses to sudden changes in input when it detects a fault.

Btw, there are two different types of drive-by-wire systems on E46s. One style uses pedal linkage to actuate two potentiometers, the other style is an enclosed pedal. I believe you have the latter, which uses hall sensors, so you need to apply +5V (as the DME does, but you could probably use a little more/less) across pins 5 and 1 and measure voltage at 4, or across 3 and 2 and measure at 6. One output should measure exactly half of the other.
__________________
-Kalim
(klx photo studio)

M3 drive train conversion (S54 Swap, LSD, 6MT, suspension linkage) | UUC Stg 2 Organic Clutch | OEM M-Tech II Kit
KW V2 | BBS GT4 RE | Falken FK452 | Alcon 6-pot 365mm BBK | M3 steering wheel | Powerflex bushings

Quote:
Originally Posted by koven View Post
i'd rather be gapless with no bulge
cyberkaa is offline   Reply With Quote
Old 12-23-2010, 09:37 AM   #28
iansanderson
Registered User
 
Join Date: Feb 2009
Location: Northeast Ohio
Posts: 2,778
My Ride: 2001 330CiC
PWG modules (aka. accelerator pedals) rarely go bad. the issue people are referring to is the sticky/notchy "stick-slip effect" pedal feel. It is purely mechanical and is related to the lubricant used on the pedal that causes the mechanism inside to bind when it gets hot (parked car in summer or heater on in winter) OP, you would physically feel the pedal sticking if it were to blame. Also, the EML would go to failsafe if there were any issues with the potentiometers in the pedal so I doubt that's it.

Since the condition changes with altitude, I would look to an intake leak like the DISA valve. It seems like they tend to go bad in the winter.
__________________



Cheat Sheet:

GT1/ISIS/MoDiC = Factory authorized diagnostic system used by BMW dealerships across the world.

NCS Expert = BMW Factory R&D programming tool available on the internet (not intended for the public and not available to the dealership network)

OEM = Genuine BMW part only available from a franchised BMW dealership.

DME = Engine Management Computer
iansanderson is offline   Reply With Quote
Old 12-23-2010, 02:02 PM   #29
Fr3nch
Registered User
 
Join Date: Oct 2010
Location: SW
Posts: 26
My Ride: :/
Quote:
Originally Posted by iansanderson View Post
PWG modules (aka. accelerator pedals) rarely go bad. the issue people are referring to is the sticky/notchy "stick-slip effect" pedal feel. It is purely mechanical and is related to the lubricant used on the pedal that causes the mechanism inside to bind when it gets hot (parked car in summer or heater on in winter) OP, you would physically feel the pedal sticking if it were to blame. Also, the EML would go to failsafe if there were any issues with the potentiometers in the pedal so I doubt that's it.

Since the condition changes with altitude, I would look to an intake leak like the DISA valve. It seems like they tend to go bad in the winter.
I completely agree. I have read up on the stick slip effect and I know it was not that. I had a vacuum leak test done, and it passed, so I figured it could be the pedal, disa, ICV or TB. I pick the cheapest to rule out and am working my way up to the most expensive.

Also, I found a bunch of info on the Hall sensors. take a look here: http://www.bmwmotorsports.org/BMW_docs/m54x5.pdf
Is there a place that has a lot of technical info on the E46, like the voltage in and out for other sensors/actuators?

Last edited by Fr3nch; 12-23-2010 at 03:34 PM. Reason: Added link to PDF
Fr3nch is offline   Reply With Quote
Old 12-24-2010, 02:27 PM   #30
Fr3nch
Registered User
 
Join Date: Oct 2010
Location: SW
Posts: 26
My Ride: :/
Quote:
Originally Posted by cyberkaa View Post
Btw, there are two different types of drive-by-wire systems on E46s. One style uses pedal linkage to actuate two potentiometers, the other style is an enclosed pedal. I believe you have the latter, which uses hall sensors, so you need to apply +5V (as the DME does, but you could probably use a little more/less) across pins 5 and 1 and measure voltage at 4, or across 3 and 2 and measure at 6. One output should measure exactly half of the other.
This was spot on! thanks for the info. Here is what I did. USB is 5V so you can take a USB charger for a phone (iphone / ipod / etc) and plug an old printer cable into it. Then cut the other end of the printer cable off and use the red and black wires. Instant 5V power supply. (Double check the 5V with a multi meter before connecting it to the pedal).

hall sensor 1: Pin 1 = negative, Pin 5 = positive, measure at pin 4
hall sensor 2: Pin 2 = negative, Pin 3 = positive, measure at pin 6
measure each sensor separately, red lead of your multimeter on 4 or 6, black lead on 1 or 2 respectively. Make sure your volt meter is set to voltage. Now depress the accelerator pedal and you will see the voltage change.

Results: I got .72V - 4V on sensor 1 and .37V - 2.0V on sensor 2. From what I have read, sensor 1 should be .5V - 4.5V and sensor 2 should be .5V - 2V. Since the maximum is 4V instead of 4.5V I am only getting 88% of max throttle, I believe this warrants a replacement. If you disagree let me know.
Fr3nch is offline   Reply With Quote
Old 09-19-2011, 02:56 PM   #31
barchetta
Registered User
 
Join Date: Aug 2011
Location: Pullman
Posts: 1
My Ride: United States
I know this thread is getting a bit old, but I hope you found a resolution. I recently picked up a 2002 325xi that behaves exactly as you described in your original post.

Did you get it resolved?
barchetta is offline   Reply With Quote
Old 09-19-2011, 03:14 PM   #32
blinkerfluid
Registered User
 
Join Date: Jan 2011
Location: Northern Nevada
Posts: 42
My Ride: 2002 325xi
Unfortunately, I have not resolved this and have decided to give up for now. I know it is not the pedal, the maf, the tb, or the icv. Since the problem is predictable and not constant, its safe to assume its not a mechanical failure. I am 90% sure it is a software issue or a speed sensor issue. My dealer charges $120 for a software update so I decided to let it ride and see if it gets worse. If you really want it solved I would take your car to the dealer and make sure the software is up to date.
blinkerfluid is offline   Reply With Quote
Old 09-19-2011, 04:43 PM   #33
bobtoronto
Registered User
 
Join Date: Aug 2009
Location: Toronto
Posts: 310
My Ride: 2003 320i
Does anyone know the latest version numbers for the various modules software?
__________________

  • 2003 320i - 5MT - Sport Package - 3.38 diff
bobtoronto is offline   Reply With Quote
Old 09-19-2011, 04:49 PM   #34
rwall
Registered User
 
Join Date: Jan 2010
Location: WA
Posts: 300
My Ride: 2004 325ci
Here's a crazy idea: with the engine off, press the pedal to the floor with your hand as hard as you can, then release. Is it springing back immediatly, or sticking?
rwall is offline   Reply With Quote
Old 12-07-2011, 12:05 AM   #35
HakenTT
OEM ///Member
 
Join Date: Aug 2009
Location: gross deutsches reich USA
Posts: 526
My Ride: 323i with S54
I have the same problem, almost got into an car wreck because of the anoying 1 to 2 second throttle response delay. It gets worse when I use heater and set it to blow down on feet, this would explain that heat is effecting the pedal and module.
HakenTT is offline   Reply With Quote
Old 03-18-2012, 05:18 PM   #36
alexxander.foster
Registered User
 
Join Date: May 2008
Location: San Francisco, CA
Posts: 171
My Ride: 2000 323i
Hey guys, just wanted to make an entry to this thread for future reference.

Cyberkaa mentioned that there were two types of pedal control modules (PWG): one with a potentiometer and one with a hall-effect rotary angle sensor. I was able to confirm this but there's almost no information on which part number corresponds to which type of sensor.

After some thinking I realized there's a fundamental difference between the two sensor types that make them easy to identify:
- The potentiometer is a physical connection (i.e., theres a contact that slides along a resistor to get a signal). It will yield a varying resistance value between the positive lead and the signal lead whenever the pedal is depressed -regardless of a power source being supplied.
- The hall-effect sensor is a magnetic field induced signal (i.e., theres no physical connection between the signal wire and the power source). Therefore it will yield an unchanging resistance value when the pedal is depressed. A 5v power source MUST be applied to get any reading from the signal leads if you have the hall-effect rotary angle sensor style throttle pedal.

Fr3nch had a fantastic idea to use an old 5v DC phone charger as a power source for a bench test, do that if you need to take it out of the car.

notes:
Pin assignments:
Sensor 1
- Positive lead = pin 5
- Signal lead = pin 4
- Negative lead = pin 1

Sensor 2
- Positive lead = pin 3
- Signal lead = pin 6
- Negative lead = pin 2

Accelerator Pedal Module (with hall effect style rotary angle sensor):
PN: 35426786282
alexxander.foster is offline   Reply With Quote
Old 03-18-2012, 05:24 PM   #37
SpoiledBrat
Registered User
 
Join Date: Nov 2010
Location: Southern California
Posts: 122
My Ride: 330Ci zhp
I had this issue you stated: "Some other possibly related things (that I am not even sure are problems): when the engine is revved briefly, it dips below idle, then goes above idle, then settles at idle. If the engine is revved high is does not do this."

as well as loss in power around 2800-3000 rpm, it resulted in a jerking feel. I fixed it by updating the DME software. My car used to stall all the time in traffic due to the issue above, but I haven't stalled since.
SpoiledBrat is offline   Reply With Quote
Old 03-23-2012, 10:56 AM   #38
Brittany
Registered User
 
Join Date: Sep 2009
Location: Atlanta, GA
Posts: 22
My Ride: '01 330ci 5spd
I have been battling this same issue to a T, with the addition of acceleration surge around 2,500-3k rpm.

I have replaced the MAF, tested and re-sealed the DISA, with a minor improvement

Things which affect the symptoms include very humid/rainy, and AC use.
Brittany is offline   Reply With Quote
Reply

Tags
intake, response, throttle

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On
Censor is ON





All times are GMT -5. The time now is 08:29 AM.


Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2014, vBulletin Solutions, Inc.
(c) 1999 - 2011 performanceIX Inc - privacy policy - terms of use