Non Boxster Question 1997 - 911 - 993 Model 993630 - Cabrio
 

Since we have a few experts here I thought this question might be worth a try.

A friend of mines car, 1997 Porsche 911 - 993 Model 993630 - Cabrio had the battery die. He replaced the battery, but the car will not turn over. Alarm (Horn) sounds, it accepted the Radio Security Code. The key fobs do not lock or unlock car. Have to use the actual key to unlock the car.

The dealer has had it for a while and has had trouble diagnosing an issue.

The car is garaged - I don’t know if they have the same issue with water on the floor immobilizer - but this car did not get wet.

The dealer has settled on changing out the passenger door latch as probable solution.

Does that sound like a plausible solution?

Thanks

Door latch? I wouldn’t think that would be the issue. Offhand I’d think it would be related to the Drive Block, but I’m more versed in the 964 than the 993.

Sounds like the alarm system is still active, so the car won't start.

993 have also the alarm module on the floor below the seats. So water is a possible option.

Key fobs can be checked, but i doubt that a normal workshop can do that, because you'll need a spectrum analyzer and you'll need how to decode the signal and you need to know what you are doing.

Passenger door latch. I don't think that is the problem, because the door locks are operated separately. So if you remove the door lock connector on the passenger side the drivers side should be still operable.

It's more possible that there is a ignition lock problem and that the key fobs don't send a proper signal or that the alarm module has a problem.

Maybe check for a different workshop that is specialized in 993 electronics.

Thank you both. I have reached out to my friend to see if the issue has been resolved. He has been out of town and has not responded.

I spoke to my friend today. He is soon to get the car back. It appears that the issue was the immobilizer. The Porsche dealership is saying the solder joints were failing on the board. Although he has the tags for the original keys they are telling him they cannot add used keys to the new immobilizer.

If he has the tags then they absolutely can add them. They or the immobilizer dont know if they are "used", sitting on a shelf in the back of a warehouse or 5 minutes off the mfg line. The tags are what is used. If it's a new immobilizer then there are no keys in it.

Sounds like the dealer just wants him to buy more.

This would also the first of hearing about solder joints on these models. The 80's/early 90's DME's were plagued with this issue but were easily fixed with just reflowing the joints with some new solder (something a dealer wont do though). It's more likely water caused an issue and not a bad solder joint. The dealer also wouldn't even put it under a scope to look at the joints. I doubt they would even open the case to look inside.

Have him find his local club which will have someone that has the pwis that can add keys for him.

We both thought the dealer is trying to pad the bill for new keys. I suggested he get the old DME as I thought one of the places that does service them might buy it just as a core.

Is it the DME or immobilier? 2 very different things. Your note said the immobilizer was the issue. Isn't the DME in the trunk on that model or is it in the pass footwell by the firewall?

Another thing....how do they know it was the immobilizer that fixes it if they didn't program in a key? Sounds fishy to me. I would find an indy shop that local club members use that is trusted even if it meant a tow from the dealer.