[Jedblad]

Hey everyone

First off, been researching bimmerfest.com for years, finally have a problem I cant find a real clear direction on. So with that, thanks for all the past help, and Please help me now. lol

Vehicle: 2003 530i

Problem ***x1f634;:
The DSC light is on
The ABS light is on
The BRAKE light is on
The AIR BAG light is on
Pulled 2 codes (52 and 53)
First one is for the rotation-rate sensor, line
Second one is for the transversal acceleration sensor, line

What the Vehicle is doing:
When I view the live data stream for the abs module on my scan tool, both the rotation sensor and the transverse acceleration sensor data is jumping all over while the vehicle is motionless.

I have located the rotation sensor under the drivers seat and ordered a new one.

I CAN NOT FIND THE TRANSVERSE ACCELERATION SENSOR. I dont see it under the A pillar, under the seat, in the trunk... etc

Please help!!
If you need it, here is the last 7 of my vin
Ck36713

Thank you!!

 

[Chedley]

Are you sure you are correctly reading the error codes ? Which scan tool are you using to scan the errors ?

You may be chasing the wrong problem of rotation/acceleration sensors.

Errors 52 and 53 indicate a wheel speed sensor (front right and rear left) errors, from the ABS module DSC57.
Defective speed sensors is a pretty common problem causing the trifecta (ABS/DSC/Brakes) lights.

 

[Jedblad]

Would that cause the readings to fluctuate?
Idk if you saw, but I uploaded a pic of my scan tool with the codes on the screen.

Thank you for the reply!!

 

[Jedblad]

I should ad, that when viewing the live data, I can spin each wheel while on my hoist and it will read speeds on my scanner.

 

[edjack]

I vaguely remember that there is a module in the left rear corner of the trunk that measures acceleration, and is related to car control.

 

[Jedblad]

Edjack, is it in the same spot that the 6 disc changer would be? Kind of a bigger silver box??

 

[528iAut]

Live data has limits, I believe there will be no data under a certain speed. Check all the sensors wiring, most of the time the insulation is gone and wires will short out randomly. Is everything else working, speedo etc? Codes do not always refer to faulty parts not performing, but that they get wrong, or no feed so problem can be before that.

 

[Chedley]

Would that cause the readings to fluctuate?
...

Bad or defective sensors. The input to the readings comes from the sensors. :angel:

The other sensor you are alluding to is the "yaw sensor", located under the driver seat.
Yes, it can throw an error code, that is often misleading. Because when the trifecta lights are activated- the ABS / DSC are effectively disabled, and henc the yaw sensor may detect the car dancing...and logs an error code.

So, as 528iAut advised, I'd start by checking the ABS speed sensors and their wiring.

 

[Jedblad]

Tested all sensors, all working. Can anyone tell me where that dang transverse acceleration sensor is? I cant find it anywhere on this thing. Maybe one of you have a service manual?? Thanks!!

 

[Jedblad]

I know where the rotation sensor is (under driver seat) and have a replacement one that will be here tomorrow fyi.

 

[Chedley]

Free advice: Do NOT replace that rotation or yaw sensor under the driver seat, until you fix and resolve the trifecta (ABS/DSC/Brakes) lights.
The error code thrown by the yaw sensor may be a consequence, not the cause, of the problem. I have experienced it a couple times on my car.

 

[Jedblad]

I wont install that sensor until I find that acceleration sensor. Which I STILL can not find. I now have both front seats out and have looked at both floor boards and along the tunnel for it... no luck

 

[Chedley]

While the seats are pulled, check out the wirings and and dry them out of any water or moisture. The fix to the problem may be that simple : corroded or wet electric connections.!!

 

[Jedblad]

Well.... finally said the hell with it and unplugged the rotation sensor... it shorted out and burnt the plug. (See pic) Put the new sensor in and cleaned the pins. Plugged my scan tool in and rezeroed the sensor. Everything working good! Thanks for all the replies!!