Hi Spinney,

First off don’t panic! It is actually quite difficult to permanently damage most of the electronic systems on the car as they have to be exceptionally robust to perform in the automotive environment in the first place.

You really just need to work through things methodically and test the individual systems. If you haven’t already got a copy of the service manual then I would suggest you download that first (do a search on here for the link to the file) so you can refer to the relevant sections and wiring diagrams. There are also step by step diagnostic procedures that are worth a look.

Is the car actually running and performing normally at the moment apart from having the dash lit up like a Christmas tree? You say that they shorted out your ABS module, spoiler switch and tranny module. Do you mean that all these modules/functions are now inoperative or they tried shorting things as part of their diagnostics?

If your spoiler has deployed permanently don’t assume that this is a problem with the switch, the ABS system (Controller Antilock Brakes) actually does this when in fault mode! I suggest you check out all the connections to the wheel speed sensors (in the wheel wells and at the CAB) Note of caution though - the service manual has the wrong annotation for the CAB unit, but the wiring is fairly obvious and can be traced from the connector behind each front suspension tower in the engine bay. The CAB will stay in fault mode until it receives four good speed sensor signals when you drive off. Under the fault condition I get a 5,000 rpm rev limit on my 6-speed too, but that may not be the case with your Autostick.

The CEL (check engine light) will remain on even after a fault has cleared itself and may have been tripped when the dealer was performing his ‘tests’. So the first thing I would do if you don’t have a scantool is disconnect the battery for half an hour or so and then reconnect it. The CEL will now either stay off if the original fault/test that tripped it has been rectified, or come back on again if there is still a problem. If the latter is the case then I would really recommend spending $50-$100 on a scantool, any of the ELM327 based DIY stuff and some open source software will work for reading codes and resetting the CEL... They will also allow you to log real-time sensor data, although not all are supported (fuel pressure is one that springs to mind). As HDDP says the genuine DCX DRBlll runs around 7k but you don’t really need that to diagnose most things..

I really wish I was that side of the pond to help you out more but take HDDP up on his offer since he has been on the receiving end of most of what the car’s systems can throw at you. Good Luck with it and keep us informed of progress.