Newbie Help. ABS/DSC not working...

[Tassadar]

Just took delivery of a 2007 Z4MR. My first BMW!

Issue:
(1) When I slam on the brakes, the wheels lock up and I slide. ABS does not kick in.
(2) When I press the DSC off button, nothing happens. No dash lights come on. I also tried to press and hold for 20+ seconds and still no lights come on.

I tried researching the issue and all I found were people that had the ABS/DSC/Brake lights all come on at once. I didn't find anything where the lights DON'T come on.

help?

[inTgr8r]

To start, check for codes and have a look at fuses.

[RossBMWZseries]

Originally Posted by Tassadar

Just took delivery of a 2007 Z4MR. My first BMW!

Issue:
(1) When I slam on the brakes, the wheels lock up and I slide. ABS does not kick in.
(2) When I press the DSC off button, nothing happens. No dash lights come on. I also tried to press and hold for 20+ seconds and still no lights come on.

I tried researching the issue and all I found were people that had the ABS/DSC/Brake lights all come on at once. I didn't find anything where the lights DON'T come on.

help?

Tassadar congratulations on your first BMW, very nice choice of car to start off with!

Anyway, what he ^ said. Check for fuses and possibly codes. Maybe the DSC is not being disabled at all, or maybe it's disabled but the dash light isn't coming on

Be careful driving that thing, don't underestimate it specially if DSC is possibly not enabled. And be careful with your wallet, the mod bug will kick in soon!

[Tassadar]

Good suggestions. I'll check the fuses and I'll plug in my odb2 reader tonight. I bought that thing a while back and never actually used it.

[Punisher3.0si]

It will take more than a generic OBD2 reader to pull ABS codes. When you turn the key to the run position (engine off) does the ABS and DSC lights come on?

[Efthreeoh]

Use a BMW scan tool and scan for codes. It's probably a bad wheel speed sensor.

[Tassadar]

Originally Posted by Punisher3.0si

It will take more than a generic OBD2 reader to pull ABS codes. When you turn the key to the run position (engine off) does the ABS and DSC lights come on?

No, those two lights don't turn on at all. The other indicator lights do.

[Punisher3.0si]

Originally Posted by Tassadar

No, those two lights don't turn on at all. The other indicator lights do.

Ok it sounds like a more serious problem that's going to require some diagnosis. Possibly a module or a networking fault. At this point I would see if it's possible to communicate with the ABS module.

[Tassadar]

OBD2 read: No fault codes.

Fuse test: Tested 7, 24,30, 42, 43 and all conduced electricity fine.

Just doesn't makes any sense to me:
1) The center console light does not come on, even during initial engine start. That means maybe that light is broken but everything still works.

2) However, ABS for sure doesn't work because I slid with full wheel lock so something definitely doesn't work.

3) If the ABS and DSC actually does not work, then the center console lights should come on (and maybe check engine light should come on). However, OBD2 reads no faults!

Very confused.... If the ABS/DSC module is broken, then wouldn't there be a fault code? My reader may not recognize the fault code but there should at least be a code shouldn't there?

[StickMon]

I just checked mine, and the yellow ABS and DSC (circle thing), on either side of the red BRAKE light, come on for about 2 seconds max and then go out. Only the EML and SES yellow lights stay lit.

[Tassadar]

Mine stays dark always

I ran out of ideas.
Gonna have to bring it into the shop.

[Efthreeoh]

Originally Posted by Tassadar

OBD2 read: No fault codes.

Fuse test: Tested 7, 24,30, 42, 43 and all conduced electricity fine.

Just doesn't makes any sense to me:
1) The center console light does not come on, even during initial engine start. That means maybe that light is broken but everything still works.

2) However, ABS for sure doesn't work because I slid with full wheel lock so something definitely doesn't work.

3) If the ABS and DSC actually does not work, then the center console lights should come on (and maybe check engine light should come on). However, OBD2 reads no faults!

Very confused.... If the ABS/DSC module is broken, then wouldn't there be a fault code? My reader may not recognize the fault code but there should at least be a code shouldn't there?

Ugh! you are not listening to us. Some education...

OBDII:

OBDII is a standard on-board diagnostics system that ALL cars model year 1996 and forward must be equipped with to be offered for sale in the USA. I'll not delve into the history (California Air Resources Board - CARB), but OBDII was developed for standardized monitoring of the health of the combustion control systems (exhaust emissions) of the engine, which includes the combustion process within the cylinders of the engine. That means OBDII monitors the function of the intake, ignition, and exhaust systems of the engine. Because modern cars use computer control (its called an ECU - engine control unit) to effect proper combustion within the cylinder there is an ability to store trouble codes in the computer's memory. The trouble codes are captured by sensors and an expected mathematical result of the combustion process (or alteration there of). Trouble codes then trigger the MIL (Malfunction Indicator Light). The MIL on BMWs is referred to as the SES (Service Engine Soon) light. The OBDII reader or scan tool reads those fault codes. The fault codes are standardized throughout the automotive industry. The difference between a "reader" and a "scan tool" is the scan tool can monitor the operation of the various combustion control systems of the engine using real live data. A Reader only reads the trouble codes. OBDII only monitors the function of the engine.

NON-OBDII:

Okay, so the same computer monitor functionality similar to OBDII is used in other locations and for other parts of the car. Modern cars have multiple computer control modules that control and monitor other functions of the car. So manufacturers use the same technique as OBDII to have the ability to read trouble codes stored in the various computer modules of the car. The situation is that these functions are not standardized throughout the industry and each manufacturer has a unique system (i.e. hardware and software) in their brand that is not compatible with other brands, so to read the trouble codes in these "other" computer modules, you need a manufacturer-specific scan tool. Just to make it slightly more confusing, each manufacturer has manufacturer-specific trouble codes for the OBDII system, which for the most part are the same as the OBDII codes other than they are in a different code format. So this means you can just use a manufacturer-specific scan tool to monitor both the emissions equipment (as OBDII does) and the rest of the other control modules - i.e. you don't need an OBDII scan tool/reader if you have a manufacturer-specific scan tool, it does both jobs. To make it convenient, the manufacturer-specific (non-OBDII) monitor system can be accessed through the standardized "OBDII" connector under the dashboard. So you plug into the OBDII port using the non-OBDII manufacturer-specific scan tool to access the non-OBDII trouble codes. The ABS/DSC lights that are on are indicating there are trouble codes stored within the ABS/DSC module (computer). You need a BMW-specific scan tool to access the codes to help diagnose the system.

With an ABS/DSC fault, you always look for wheel speed sensor fault first. The DSC (dynamic stability control) uses the wheel speed sensor data to function, so if there is a bad wheel speed sensor it with cause both the ABS and DSC not to work correctly. You need to scan the car for the codes so you know which wheel speed sensor is faulty. Each wheel has a speed sensor, so there are 4 in total.

Good luck with it.

[StickMon]

Originally Posted by StickMon

I just checked mine, and the yellow ABS and DSC (circle thing), on either side of the red BRAKE light, come on for about 2 seconds max and then go out. Only the EML and SES yellow lights stay lit.

Correction: It's actually yellow ABS and brake pad sensor lights that come on briefly.