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Posted

Hello all! I'd like to apologize in advance if I'm breaking any rules never been in a forum before! Anyway here the problem I bought a 98 boxster that I'm having immobilizer trouble because I'm not sure if the car even runs or if it's worth trying to get it going I cant get past immobilizer to see if car is worth fixing there has to be a bypass so diagnostic work can be done,I have one key fob it will unlock drivers door but it wont pass the fob issue alarm isn't going off but I turn key and dash lights all come on but no start can anyone help me do I can get to the real issue of if car even runs without spending $1000 before I can even start working on it thank you for any help at all

Posted (edited)

I guess the first place to look is under the driver's seat carpeting to see if there's any water damage visible. If there is, then you'll need to get into the alarm/immobilizer unit on the underside of the seat to see if there's water damage to the internals of that.

Edited by wizard
Posted

Check fuses C1 to C4 and E1 first. If it is a stick shift, jump the clutch switch too.

 

Do you know if your key fob ever works on the car? I.e., are you sure it matches the immo?

  • Moderators
Posted
23 hours ago, Airborn456 said:

Hello all! I'd like to apologize in advance if I'm breaking any rules never been in a forum before! Anyway here the problem I bought a 98 boxster that I'm having immobilizer trouble because I'm not sure if the car even runs or if it's worth trying to get it going I cant get past immobilizer to see if car is worth fixing there has to be a bypass so diagnostic work can be done,I have one key fob it will unlock drivers door but it wont pass the fob issue alarm isn't going off but I turn key and dash lights all come on but no start can anyone help me do I can get to the real issue of if car even runs without spending $1000 before I can even start working on it thank you for any help at all

 

Welcome to  Rennech.org :welcomeani:

The immobilizer is purposely designed not to be bypassed, as the DME requires a ”handshake” with it before starting.  This is specifically designed this way to prevent theft.  Problems with this system due to water getting to it during rain storms and due to blocked drains it a very common issue with these cars.

 

Look at the immobilizer under the driver’s seat, if it shows signs of corrosion, or the small fuse in it is blown, you may need to either send it out for repair, or replace it.  Replacing it is not a DIY proposition as it must be coded to the car with a PST II or PIWIS unit, and the unit is pricey, so hope it can either be cleaned up or repaired.

 

Good luck.

Posted

Thank you for your responses ,I was told by former owner that the key fob does match immobilizer that all components match,that it just quit working after purchasing the car had a dead battery and battery in key fob was dead after replacing both batteries I can manually unlock doors put key in ignition lights all light up but no start I've checked the immobilizer under drivers seat it appears brand new no signs of moisture fuse not blown,I'm not apposed to buying new immobizier components but I'd hate to do that then find out the motor doesnt run I was looking for a way to see if it even runs before I start dumping money in something that doesn't run

  • Moderators
Posted
33 minutes ago, Airborn456 said:

Thank you for your responses ,I was told by former owner that the key fob does match immobilizer that all components match,that it just quit working after purchasing the car had a dead battery and battery in key fob was dead after replacing both batteries I can manually unlock doors put key in ignition lights all light up but no start I've checked the immobilizer under drivers seat it appears brand new no signs of moisture fuse not blown,I'm not apposed to buying new immobizier components but I'd hate to do that then find out the motor doesnt run I was looking for a way to see if it even runs before I start dumping money in something that doesn't run

 

You are between a rock and a hard place on this one.  Without a functioning immobilizer, the DME will not let the car start; without a PST II or PIWIS unit, you cannot see if the two actually do match and communicate correctly.  There simply is no simple work around for this as it is the way the car was designed.

Posted
On 10/5/2018 at 8:36 PM, Airborn456 said:

I turn key and dash lights all come on but no start...

What kind of diagnostic have you done so far to fault the immo? There are a few non-immo related faults that can produce the exact symptoms you mentioned.

Posted

I would be curious to know why there's what appears to be a "brand new" immobiliser unit in a 1998 car? Does the part number on the unit match that specified for a car of that year?

 

As I mentioned before, is there any sign of water damage under the carpet under the driver's seat?

Posted

There is no water damage under the seat the car has just over 100,000 miles it doesnt have a scratch on it convertable top us like new even the back plastic window doesnt have a fold or mark on it the interior has a small wear spot on drivers seat other then that interior looks fantastic carpet doesn't appear to have ever been wet any where,it appears like it's been inside most of the time

Posted

I've not done much diagnostics dont know where to start to this point I've jumped the starter relay to turn it over to make sure it wasn't locked up ,didn't here any unusual  sounds while it turned over all sounded good

Posted (edited)

Well, Ahsai and JFP are far more experienced and knowledgeable than I am but could it be something as simple as the electrical component of the ignition switch, I wonder?

 

That is a common problem and I had to replace mine years ago (2003 Boxster) but I can't remember the symptoms.

Edited by wizard
Posted
4 hours ago, Airborn456 said:

I've not done much diagnostics dont know where to start to this point I've jumped the starter relay to turn it over to make sure it wasn't locked up ,didn't here any unusual  sounds while it turned over all sounded good

My posts above were the starting points. There are quite a few more things to check before we even hit the immo.

Posted
5 hours ago, Ahsai said:

My posts above were the starting points. There are quite a few more things to check before we even hit the immo.

I have replaced the ignition, can I not jump the starter ,the fuel pump and ignition and start the car that way or will that not work without jumping other relays as well

  • Moderators
Posted
6 hours ago, Airborn456 said:

I have replaced the ignition, can I not jump the starter ,the fuel pump and ignition and start the car that way or will that not work without jumping other relays as well

 

Not easily.  The way the system works, when the immobilizer sees the RFID pill in the key, it sends a signal to the DME, which then activates the fuel and ignition systems so the car will start.  No signal, no DME response, and no start.  As the DME is controlling the ignition timing, spark signal, and the fuel pump, you would need to jury rig multiple systems around the DME, but then you would have no control over ignition timing, idle speed control, etc., as these are all monitored and adjusted by the DME.

Posted

only way if it is not working is to change both the DME and the immobiliser from a donor car of the same year, engine code and gearbox code...change the blades from your keys into the Donor fobs.

 

its quite an expense. worth checking it all out on the car first...sometimes the RF transmitter fails so the key transponder can't communicate with the car,the immobiliser itself can be damaged,or you could have wiring issues.

 

start simple,

 

fuses,power to immobiliser, the fuse in it etc..

 

but first try this..

 

 | 

Re: boxster remote key not working

I know exactly what is happening and it happens on my Boxster too (2003 Boxster).

Your key has lost synchronization with your car and can be reset by doing the following:

1. Manually unlock your car using the key
2. Open the car door (note if your alarm goes off, put your key in the ignition to stop the alarm.
3. Press the unlock button on your remote and the remote will resynchronize with your car.

This is stated in the owners manual but you have to look for it.

Note: If you leave your car locked for more than 5 consecutive days, the car will deactive the remote receiver to reduce battery load and you will be forced to use the procedures listed above to reset it
Posted

Thank you I will try that,you mentioned if I jumped multiple relays if it started their would be no control on engine and that would be ok at least at that point I would know it runs then I dont mind putting money in the car like I said I'm just wanting to see anything that tells me the motor is good and runs before I spend thousand dollars on it

Posted
On 10/7/2018 at 10:43 AM, wizard said:

Well, Ahsai and JFP are far more experienced and knowledgeable than I am but could it be something as simple as the electrical component of the ignition switch, I wonder?

 

That is a common problem and I had to replace mine years ago (2003 Boxster) but I can't remember the symptoms.

This is indeed a common problem, and an easy one to troubleshoot. Not overly expensive. 

Posted

you could do a compression test,

 

that would be a good indication of engine health, any HG issues would be obvious on the oil filler cap and or in the coolant.

 

if these come out ok, chances are its ''just'' an immobiliser issue, that can be solved as I said before with an ECU kit from a donor car.

 

when the time to track down the problem becomes an insurmountable obstacle or you can't find anything obvious then its sometimes worth throwing a ''speculative'' part at it.

most ECU kits can be sent back with prior arrangement with the vendor.

 

so even if it doesn;t work its diagnostically relevant.

Posted
11 hours ago, joe hurst said:

you could do a compression test,

 

that would be a good indication of engine health, any HG issues would be obvious on the oil filler cap and or in the coolant.

 

if these come out ok, chances are its ''just'' an immobiliser issue, that can be solved as I said before with an ECU kit from a donor car.

 

when the time to track down the problem becomes an insurmountable obstacle or you can't find anything obvious then its sometimes worth throwing a ''speculative'' part at it.

most ECU kits can be sent back with prior arrangement with the vendor.

 

so even if it doesn;t work its diagnostically relevant.

Thank all of you for your help it's all been helpful and I've  had a very generous forums member send me a loaner ecu,dme,keys,ignition so that I can test my boxter so I'll have it in two days I'll let everybody know how it goes,thank you all for your help I'm sure I'll be on here frequently  looking for answers to other issues that arise,talk to you in 2 days thanks

  • 4 months later...
Posted

Sorry for resurrecting this old thread, but I was wondering whether this was ever resolved?

I am a new member to the forum, and a Boxster virgin. Be easy with me! And apologies for the super long first post.

 

I have just taken possession of a 2001 Boxster 986 Tiptronic with similar issues. The previous owner went away on a long holiday, leaving his car with a friend, with instructions to turn it over occasionally. He came back to a dead battery, and after he replaced that he still could not start it. He left it at a garage for repair, but eventually (after a year!) brought it back home still not working.

 

The windows were half open and do not respond to any of the switches. I bought it at a good price (as by now he just wanted shut of it), and started investigating. Whether the immobiliser had originally been wet when it first failed to start, I don't know, but it was when I received it. I dried it off, and gently brushed off some minor corrosion, but it is the same. The alarm doesn't sound, the windows won't move, the front and rear boot won't open (although the front has been opened, and is being kept open). The doors won't open with the fob, but will with the key. All the dash lights up, ventilation system works, radio lights up (but needs a code), but the engine will not crank.

 

I have charged the battery, and changed the battery in the fob, all to no avail. Looking at all the receipts that came with the car, a fortune has been spent in the last five years, and I have no wish to add to that by just taking it to the local Porsche garage, and asking them to sort it out. I have tried all of the button pressing and battery reversal routines which I have read on various forums, non of which worked. I have had a local mechanic take a look at it, but he couldn't  get his diagnostic computer to even recognise it.This is from a guy who rescued a Boxster from the sea, half submerged, and got it to work!

 

I suppose my question is; without towing the car off to a garage, is it possible to remove the immobiliser and the ecu, and send these off with the key to have these tested without being in the car? There is a company in France that seems to break a lot of Boxsters, that sells the immobilier, ecu and key internals as a set. If these were for the right year and model, and for a Tiptronic, is this a simple plug and play, or does the car need to go back to Porsche to be 'programmed'?

 

I am in a similar position (as the thread starter) of not wanting to spend too much to resolve this issue (if at all possible) as I am still not sure of being able to resolve 'paperwork issues' which currently haunt the vehicle - a USA import that went to the Middle East and then to Europe! I really don't want to break the car for parts as I really would like to drive it.

  • 1 month later...

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