Advice Please

[ELBONN]

In the recent months you may recall I have enlightend you all to my on going saga with my instrument cluster.

Summary : All instrument cluster dials failed without warning. Changing fuses and dissconnecting the battery failed to solve the problem. A new cluster was purchased. This worked fine for 10 days before failing again. Same problem all dials not responding but some lights come on now and again. Indicator lights fine and battery guage fine. The cluster has been repleaced under warrenty.

However before my Porsche specialist fits the new cluster both they and I want to find the route of the problem.
They have checked the wiring behind the cluster for any unexpected large currents, but couldnt find any. They then suggested removing the whole dash board and checking the complete wiring loom and if all else fails replacing it at considerable expense. Shocked that this could ultimately be the only way to solve the problem I asked for a second opinion from Porsche directly. They said they would probably remove the dash as well and check for a wiring problem since 2 clusters have failed.

My Porsche specialist said they could try one more thing which is that there are 2 electrical connectors that plug into the back of the cluster and maybe replacing these would resolve the problem. One problem Porsche do not sell these connectors seperate from the complete wiring harness, so a contact they have is trying to source the parts elsewhere. Now having to wait.

Not being mechanically minded or have the first bit of knowledge regarding the electrical system I not sure what to make of the whole sage and was hoping for some advice.

A reminder that I'm based in Dubai, with one OPC and one Porsche specialist to speak with.

Thanks

 

[Richard_Hamilton]

There are 3 plugs on the instrument cluster. If you are getting some backlighting but no instruments, I would suggest that they check the pins on the plug which provides power and ground connections to the instruments. If you need a wiring diagram, email me with the model year of your car and I'll attach it to a reply. It may be that the clusters themselves haven't failed, and it is simply a power supply problem - a bad connection or pinched wire somewhere.

 

[ELBONN]

Thanks for the prompt response once again Richard. I have sent you an email. My 996 is a 2003 C4.

I assume these are the plugs they are trying to source for me. After being told Porsche would not sell them seperate to the complete wiring harness apparently they tried Audi and Volkswagen as they are the same plugs for their clusters but again no joy.

I suppose checking for a pinched wire would mean removing the dash?

Either way I will hopefully get the car back in the garage for them to check again and keep you posted.

 

[Richard_Hamilton]

I haven't received your email yet - try richard996 (at) gmail d0t c0m (Obfuscated, as the spam has started!)

There is a VW/Audi connector which fits into the cluster plugs of the 2003 cars, and the VW part number I have for it is 00.979.009. This is a "repair wire" with a connector at each end. I don't know the part number of the plug itself but this has been a useful link for WW/Audi connectors: http://www.nsxjr.com/Audipins.html

If your guys can check that they are getting the appropriate supply and earth connections it would be a starting point.

Edit: The cluster plug looks very much like this one: http://www.nsxjr.com/partpix/1J0-972-977G.jpg

 

[Richard_Hamilton]

It won't be the MAF. If it just died suddenly, and you can't crank it, it almost sounds like the immobiliser has cut in. The carpet under the passenger seat didn't get wet did it?

You are correct that you will need a Porsche tester to diagnose it though.

 

[devans]

Richard, whilst the carpet was wet it did not reach beyond the lip under the passenger seat and therefore i assumed it was caught before reaching the said unit, however it may well be that i am wrong.
The immobiliser does sound about right as everything else works. Does this have to be reset or dealt with at a dealer or can i possibly dry out with a hairdryer. Clutching at straws here, but if there is any chance of getting it going for a mile and a half to home at least it would be great!!!

 

[devans]

As another thought Richard....is it possible to bypass the immobiliser with any actions from the key or by possibly disconnecting the battery terminals for a few seconds.
Thanks
If its a stupid question i apologise in advance

 

[Richard_Hamilton]

No, you can't bypass the immobiliser - that's it's purpose!!

I have a horrible feeling that the alarm control module has got wet from the earlier episode of the leak, and if it has then it is likely to be toast. Sometimes they can be salvaged by removing the lid and drying it out, but 9 times out of 10 its a goner.

 

[devans]

Many thanks Richard for your quick response. If i tow it home and remove the passenger seat, (i assume this will be easy) is it easy to recognise the said unit to have a go at drying out, ie is it stand alone.
If not, any ideas on cost issues!!!
Many thanks again.

ps Towing will have to be late tonight so as not to be seen!!!

 

[philippe]

I had a similar problem in the south of France a couple of years ago, power cut out whilst driving along. was stuck in the middle of know where, lucky was only 45 min from my folks place and the old man towed me to safety, to the amusement of many french folk. Anyway turned out to be the Fuel pump, which even surprised the guy in the most unpleasent looking back street garage who fixed it, and was a top man.

Would be intrested to hear how you get on.

Phil

 

[devans]

Did you get absolutely nothing from the ignition....ie no noise at all when you turn the key??

 

[philippe]

Good point engine would turn over just no go.

Good luck

 

[devans]

Richard if you are still online wonder if im on the right tracks....
Been on the porsche parts catalogue and although mine is 98' the catalogue for 05' car shows part number 996 618 260 06 as the control unit for immobiliser, central locking system and alarm system....there is also a part number of 999 607 064 00 which mentions a 15a fuse.
As ive got no car at the moment to drive i would like to ask;

1. Does this mean that if the control unit houses the immobiliser, central locking and alarm and the latter two work...would this eliminate the immobiliser possibly being the problem, or
2. Could it be that there is a fuse in this unit

Anyone throw any light on this as i can't really do anything manual tonight so thought i'd delve into some technical questions albeit probably miles off the point.
thanks

 

[Richard_Hamilton]

Fuse B8 is for the alarm and engine ECU. If you pull it, it usually sets off the alarm siren. If you car locks and unlocks via remote, then I don;t think it is the fuse. The immobiliser circuit is built in to the alarm module, and if it has got wet part of the module might work, but not all. You'll be able to see the module by sliding the seat all the way forward. If you need to remove the seat, you'll need an E12 Torx Star Socket. 4 screws and it comes out easily - it's the plug underneath which is tricky to disconnect. You have to slide the housing sideways for it to come apart. I think you are correct that there is a fuse in/on the module itself. If everything is dry under there, it would be worth checking.

I guess it might also be one of the relays behind the rear seats (another area that got wet). The DME relay, which is in position 1 on the relay carrier (top left). Switch it for relay 2, to see if it will crank. (It might not run though).

Alarm control unit: 996.618.260.06 - £226.59+VAT (plus it will need programming).
DME Relay: 141.951.253.B - £10.21+VAT

 

[devans]

Thanks Richard....will have a closer look tomorrow.

Have just been out and towed it home. Have had a good look and feel under the passengers seat and it looks bone dry. However, there are some stains on the metal cover plate behind the rear passengers seat on the sort of parcel shelf. I will take this cover off and have a good look as the stains indicate that this may well be the area that got wet. Many thanks for your support again, lets hope tomorrow brings out the cheaper option.
David

 

[devans]

Todays lack of success.

1. Took out rear carpet shelf...swapped over relays 1 and 2...no luck even though my fingers were crossed.

2. Removed passenger seat...removed control unit....removed and checked 15 amp fuse connected to back of unit....opened unit up...dry and clean inside. Placed everything back....no luck.

Don't think i have any more options but to have the car towed somewhere and fixed. Mind you i'm learning a lot about the car through these posts. Unless anyone has any other thoughts!!! Many thanks again though Richard....is there anything that we could have missed??? Gone to have a sulk in the bath now.

 

[Richard_Hamilton]

Do you have another key you could try? They have an immobiliser pill in them, and although I've never heard of one going bad it is always possible.

Other than that, I think you'll need to get a diagnostic check done which (hopefully) will reveal what's going on.

 

[devans]

No....unfortunately when i bought the car 4 years ago i was only given 1 key with electronics in and 1 key blank. The electronics went wrong in the original key about a year ago and had to order another which then had to be programmed, this was a fault with the key electronics not talking to the alarm system.
The immobiliser pin inside does tend to go a funny colour, sort of green coating on the inside of the glass. I assume this is normal!!!
As an afterthought would removing fuse C1 or C2 be worth trying to see if they are broke or would this cause more problems?
I will try to phone porsche tomorrow and ask if there is a way of testing the immobiliser pin without the car present.
Thanks again

ps Thinking about it all....even if the units arent wet, how long does the control unit in these cars tend to last. Mine has done 91k. Just a thought

 

[Richard_Hamilton]

It is certainly worth checking C1 and C2, and wouldn't cause any other problems.

Is there not a decent indy in your area?

 

[Richard_Hamilton]

I've had something nagging at the back of my mind for a couple of days, and it has finally cone round the loop.

There was a chap on another forum who had a similar problem in that it was blowing fuse C1 and the engine would die. In his case, he tracked it down to chafed wiring to the variocam solenoid, which was sporadically shorting and blowing the fuse. So another reason to check C1 (and C2).