Can anyone tell me what will cause a DSC fault light to come on . I have put it on a diagnostic machine which didn't show any faults. So I'm a bit stuck .

 

There are many possibilities. Best way to find out what causes that light is to use another diagnostic tool. If you used a cheap $20 theres a huge possibility that it didn't read fault codes from DSC/ABS module. Most cheap ones will only read trouble codes from ECU.

 

Peperami, odds are, you have a bad wheel speed sensor. You should be expecting to see one of the following codes: C1145, C1155, C1165, and/or C1175. From there, it should be pretty easy to resolve the issue. You can possibly pull up the code by putting the instrument cluster into a diagnostic mode and then looking at the codes there. If you want to know how to do that, let me know. It is pretty easy to do.

On a side note, if you have a basic code reader, it is only going to read the P Codes. Hence why you are not finding any codes even though you have the check engine light. You need a code reader that does (at a minimum) P and C codes.

 

With wheel speed sensor fault it should have abs light on too bu might be that yes. I would think with DSC light only there's a problem with yaw/g-force sensor, steering wheel sensor or ABS pump itself.

 

If you don't have the fault codes or ABS warning light on with your DSC fault, please check your battery connections. Had DSC fault and eventual shut down with an arcing + battery cable.

 

My '07 Sportwagon always lights up the DSC System Fault when my battery is pooping out. Get the battery checked and you will probably find that to be the cause. Good luck.