ABS/ASC Lights on, can't get scanner to connect to ABS/ASC modules

[JeffNJM3]

Hey everyone,

Just bought a 99 323i auto vert as summer toy, and it needs some work. First trying to get all the lights to stay off. The ABS and ASC lights are on, and also the brake lining light, but im not sure if thats related or not. So i have tried to read the codes with a Launch and a Foxwell scanner and neither can connect with the ABS/ASC systems. I changed the ABS relay with another one that is known good, and still cannot connect.

Any ideas? I, thinking maybe the actual computer behind the glove box is fried? And I'm praying its not the pump!

Let me know if anyone else has ever had this problem

thanks!

Jeff

[E36328Coupe]

My 1995 328 required an ADS interface to speak to the ABS. Many say an OBDII and 16 to 20 pin works but not on the 2 cars I have (EU didn't get the OBDII socket on these).

You need to provide a decent problem description. No one knows what you are using or experiencing from your post so will not be able to help you

[JeffNJM3]

Vehicle: 1999 BMW 323i Automatic convertible.

Problem description: ABS and ASC lights are on.

What I am using: Launch and Foxwell scanners, thru the round 20 pin port under the hood.

What I would like to accomplish: Get the lights to turn off.

[MParallel]

ASC/ABS needs a K+L line aka ADS interface.

This requires either a GT1 yellowhead or laptop with rs232 port and ADS-USB interface.

Any USB port cable will not communicate with this module.

[E36328Coupe]

^^^^ Or a cheap ADS interface you can build from the "almost free ADS thread" or alternatively the relatively cheap Tiny ADS interface

You would also need the INPA software or DIS to go with it. INPA being the easiest to use

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ASC/ABS needs a K+L line aka ADS interface.
ADS isn't exactly K and L

For example Vagcom / ODBII / KKL interfaces give you both those lines and do not work. The trick with ADS is it swaps direction on one of the lines.

[MParallel]

^^
Ah ok. That was the trick.

[ZIRZBMW]

Hello all,

Having the same issue with my 97 BMW M3. Both ASC and ABS lights stay on. I used my Peake R5/FCX scanner and got the following codes:



F6
Secondary Air system flow too low - cylinder 4-6


F1
Misfire - cylinder 4


EE
Misfire - cylinder 1


53
Intervention ASC


EF
Misfire - cylinder 2



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Any advise on what I should replace 1st would be greatly appreciated. Other than the lights staying on the car runs ok.

[ed323i]

The most probable cause is a defective ABS sensor or too much debris in one of the ABS gear (at the 4 wheels).
If you have or know someone with an oscilloscope, you can get under the car and disconnect and measure the ABS sensor output one after the other. While measuring turn the wheel and see if it outputs a strong enough and stable signal with a stable on/off pattern. You can probably also disconnect the cable at the ABS computer and measure there, so you don't need to get under the car.

I did this once to find the bad ABS sensor and replace it, I think on an E34. Then ABS worked perfectly again. As ASC depends on the ABS signals, it will turn off too.
I think brake lining light turned on is not connected.. But not certain..

Good luck!

P.S. You can now get really cheap digital oscilloscopes (or even cheaper USB oscilloscopes which you connect to your laptop to read the output) which are perfect for this type of work, also for measuring VR sensor output and stuff like that.
Example of USB oscilloscope (Pikoscope being a more expensive example; search ebay or dx.com for usb oscilloscope for cheaper alternatives), measuring ABS sensor here: https://www.youtube.com/watch?v=q9TMTQuIfn4 (starts at 3:00 minutes)..

Update: The three lights (ABS/ASC/brake lining) on usually indicates ABS sensor trouble.. Check this youtube video: https://www.youtube.com/watch?v=8qrDGLvsEtk . In this video it's an E46, but also, all 3 lights are on, and after replacing the right sensor, and driving a few meters, all three lights turned off again. So 99% certain it's a defective or dirty ABS sensor (or a dirty ABS ring/gear).

Update for ZIRZBMW: I think the Peak reader only reads the DME codes, not the ABS computer codes.. So, to know which sensor you need to replace (or clean; or clean the ring) you either need BMW INPA software on an old laptop with a true RS232 serial port and an ADS interface, or you can use the oscilloscope to check which sensor (or which ABS ring/gear) is bad.

[ZIRZBMW]

Thanks Ed I will start there.