ECU fuse blows !

Following on from my earlier post about my car not starting, I have since been contacted by Porscheshop that the problem is the fuse keeps blowing for the ECU, They said I need a new ECU at nearly £900 ! Anybody else had similar problems or can offer some advice as apparently a used ECU can not be used ??? Thanks Kosmo.

Holy **** Ok, don't panic yet... go get me all the numbers on the ECU and post them here or PM me. I may be able to get it repaired. In my experience an ECU that blows fuses is actually the easiest to repair. It is normally an obvoius fault as aposed to software issues. Biggest cause of this kind of failure is water ingress so check that area for damp.. if yes you MUST find the cause, leak, missing grommet, door membrane etc Call me on 07970 079709 if you want.. I am off work today / tomorrow so I am free to talk.

ECU lloyd six, Out of self interest for me. Why can't a used ECU be used, do you know?

Re: ECU I know for sure they are coded, what I am unsure about but will get confirmed is whether this particular series of the DME can be de-coded then recoded. (This is what is required if going second hand) I am also quite certain the only equipment that car programme a DME into a 996 is PIWIS (Porsches own workshop equipment) Durametric does not have coding in facilities.

Just wanted to say thanks to Lloyd Six for all his help.... The plan is now to get my car back from Porscheshop and diagnose the fault in more detail myself, they quoted me over £1,200 to replace and re-program the ECU ! Only problem is getting the car back due to work etc... anyone local do recovery for a reasonable price... Halesowen to Telford ? Cheers, Kosmo.

The DME is programmed with the immobiliser code, fuel maps, etc with a PIWIS or PST2 tester. You need the programming (security) codes for your car in order to program a new DME (engine ECU), and they are only available from Porsche. I doubt they would give you the codes, but they will issue them to an indy on request, provided they supply a copy of your V5C and a letter of authorisation from you. (I got the codes for my car that way). Using a second-hand DME would be a problem, as not only would you need the security codes for your car, but also those from the donor car, which they won't give you.

I understand this but the fault described does not sound like an direct ECU fault, morel like a wiring fault... or if it is the ECU it's more likly to be able to be repaired as blowing a fuse is a short circuit. As Lloyd Six has pointed out to me, software errors would not blow a fuse ! Also, Lloyd Six has reccomended RSR who can assist if the ECU does require a replacing.

Everyone is correct, as Richard said the programming can only be done with official Porsche equipment. Like I said earlier we would need to get your car into Reynolds, the Porsche app. body shop who have PIWIS. Did you find out whether the fuse blew instant or under ignition activation?

I wish you luck in getting the DME repaired if it has blown something internally. I would imagine that they disconnected the DME to see if the fuse blew again, which would indicate an external wiring fault. My feeling is that the guys at Porscheshop have a good idea of what they are doing, but we'll have to wait and see, and I would be delighted to be proved wrong.

I'm sure Porscheshop know what they are doing, however since speaking to Llyod six I have a few more options and hopefully in the end this will save me money, fingers crossed.... :?:

Lloyd, Not had a chance to speak to the tech at Porscheshop about when it blows, will do today when I get the car back.... going to give Nick at ATP a call to about possible options, repair/replacement etc... Again thanks for all your help, Andy. :thumb:

Hi, This sounds very rare in deed. any help required ? I can get you in touch with a guy I use for my recovery's he is based in Knutsford but very reasonable. Which fuse is blowing? It may protect more than the DME when you look at the wiring diagram can check for you today if you get me the fuse number ... probably C1 or C3 for engine electrics off top of my head. Mike

Hi Mike, I've got the car back now but not managed to look at the problem due to work commitments, hoping to do this tomorrow so will post update then. Thanks for the offer of help, if I get stuck I will be in touch..... Thanks Andy.

OK, here's an update, found a wire going to the solenoid on the drivers cam cover burnt, tested the solenoid for cylinders 4-6 and its a dead short.... Going to repair the wire but need help on replacing the solenoid, anyone done this who can offer advice ? Thanks Andy.

Hi Folks, I am dealing with the same issue. I have chased grounds, replaced the dme relay, the fuel pump relay, and sent the brain for testing, with no solution. I will check the solenoids next... I will post any answers I may find. Andy :thumb: