Help! DSC / BRAKE / TPS warning lights permanently on

[ckkcz4]

Hi Everyone,

Since few weeks ago my 2004 Z4 has DSC / BRAKE / TPS warning lights (YELLOW) permanently on all of a sudden. I have INPA and have done everything I could but still can't fix it.
I have the battery light on occasionally as well. I have the battery replaced last week and the battery light never come on again till now. But the DSC problem reminds the same.

From INPA, 4 wheels speed sensors and the steering angle sensor give decent readings.
However the DSC voltage URef is reading odd which stay at 9.9V and jumping to 0V for 2-3 times/sec, and the voltage pump reminds 0V. (see attachment)



Another thing is that seems like the DSC button itself is not connected to the system. I used INPA which shows the status and when I press the TPS, the screen shows it's ON, but when I press the DSC button, the screen shows it's still OFF, nothing happened.
I tried to disconnected and reconnect the DSC button harness and also the DSC Hydro unit harness with no luck.
I also tried to disconnect the battery for more than 1 hr and also with no luck.

Below is the error code

F E H L E R S P E I C H E R L E S E N
---------------------------------------
Datum: 09.02.2013 16:07:23
ECU: DSC_MK60
JobStatus: OKAY
Variante: DSC_MK60
-------------------------------------------------------------
ERGEBNIS: 2 Fehler im Fehlerspeicher !
-------------------------------------------------------------
5D8C Sensor-Cluster Timeout CAN
Fehlerh酳figkeit: 1
Logistikz鄣ler : 40
Kilometerstand 55160 km
Vehicle speed 0.00 km/h
Brake light switch 0.00 0/1
switch brake fluid level 0.00 0/1
ASC/DSC_aktive (status of ASC/DSC_switch) 1.00 0/1
brake pressure identified 0.00 0/1
ABS-active 0.00 0/1
ASC-active (BMR) 0.00 0/1
ASC-active (AMR) 0.00 0/1
GMR-active (GMR) 0.00 0/1
GMR-active (MMR) 0.00 0/1
CBC-active 0.00 0/1
MSR-active 0.00 0/1
TDR-active 0.00 0/1
SDR-active 0.00 0/1
DBC-active 0.00 0/1
RTA active 1.00 0/1
Run-Up Mode 0.00 0/1
No matching error symptom
Test conditions fulfilled
Error present now and already stored
Error would cause a warning lamp to light up
Fehlercode: 5D 8C E0 01 28 15 8C 00 0A 00 04
-------------------------------------------------------------
5D97 Sensorcluster Supply voltage out of range
Fehlerh酳figkeit: 1
Logistikz鄣ler : 40
Kilometerstand 55160 km
Vehicle speed 0.00 km/h
Brake light switch 0.00 0/1
switch brake fluid level 0.00 0/1
ASC/DSC_aktive (status of ASC/DSC_switch) 1.00 0/1
brake pressure identified 0.00 0/1
ABS-active 0.00 0/1
ASC-active (BMR) 0.00 0/1
ASC-active (AMR) 0.00 0/1
GMR-active (GMR) 0.00 0/1
GMR-active (MMR) 0.00 0/1
CBC-active 0.00 0/1
MSR-active 0.00 0/1
TDR-active 0.00 0/1
SDR-active 0.00 0/1
DBC-active 0.00 0/1
RTA active 1.00 0/1
Run-Up Mode 0.00 0/1
No matching error symptom
Test conditions fulfilled
Error present now and already stored
Error would cause a warning lamp to light up
Fehlercode: 5D 97 E0 01 28 15 8C 00 0A 00 04
=============================================================


I doubt the DSC hydro unit need to replaced but it cost horribly... so is there any suggestion on what I should looking at?
Thanks in advanced and excuse me for my bad english.

Kevin

[bcworkz]

Hello there, welcome to the forum!

I've no idea what or where those voltages represent, but it does indicate something is not right. (Genius diagnostics, eh? ) Have you had any water ingress issues? A few people have had DSC issues after getting rained on with the roof down. The main DSC unit behind the hand brake seems to be well located to get soaked when this happens, the result being knackered electrics.

[ckkcz4]

I dun have any water ingress issues but I have no idea where the main DSC unit is. Is it like a little metal box ECU thing between the hand brake handle and the rear storage box??
thx~

[ap208_1988]

After changing the battery you need to recalibrate the steering angle sensor i think. Did tou try that?

[simvaughan1]

All those warning lights signal something potentially wrong with the speed sensors. When you drive around do they all change voltage? (Not 100% sure what they should be doing mind)

There is a generic issue with wheel speed sensors if they get caked in muck. Cleaning them off allows them to read true again. If the car doesn't know what speed each wheel is doing, it can't figure out the tyre pressure monitoring, or have a hope in hell of any stability control or traction control!

Worth a shot I guess.

[ckkcz4]

Thanks for all your suggestions.
I guess I have done the steering angle sensor recalibration by full left turn and full right turn the steering wheel.
And those 4 speed sensors give correct reading as I tested accelerating from zero to 3x km/h, as well as the steering angle sensor.

I tried to clear the code but failed. The problem reminds permanently so my guess is something wrong with the wire and voltage to the unit as the DSC button doesn't give any response as shown in INPA. But I have no idea what's next I should look into.

[juld0zer]

Hi Kevin,
Did you find the problem?

[Chris_D]

image.jpeg (206.43 KiB) Viewed 1715 times

I would certainly hope he has it sorted by now....