Smhube00

Hi guy
I am new here. I have a 2002 boxster s.

Igot this car from friend of mine. He left the top open and water got in. Car wouldn't start after that.

He took it to dealer , they replaced the alarm module and gave them a new key. Still they could not get I to start.
He gave me the car after that.

I took the car to a Indi shop, after running diagnostics for 4 hours they cam back said alarm module is prevent car from starting. I told them to stop working on it. They were able to access the dme/ECU.

Anybody have any ideas where to start trouble shoot this ? Is there any way to bypass the alarm module

Thanks in advance

Byprodriver

Lots of threads on this, search "immobilizer" for info.

Macster

No way I know of to bypass the security system.

If the car got wet if the security module got wet dry it out and hope for the best. This is located under either the passenger's seat or the driver's seat. In some cases the thing has to be removed -- the seat may need to come out -- cleaned and dried. (I've manage to salvage keyboards with coffee spilled on them by rinsing with hot water and then distilled water and placing in a dish rack then outside in the sun to thoroughly dry.

The DME/ECU is a separate module located on front of the trunk and is rarely affected water in the cabin.

Smhube00

Actually when we took the car to the dealer they change the alarm module and reprogrammed it

Still could not get to start

Macster

If the diagnosis was the alarm module needed to be replaced to address the no start symptom then the diagnosis was wrong. Take the car back and insist the dealer remove the new alarm module -- it was replaced unnecessarily -- and install the old one undo any programming that would interfere with the proper operation of this old but functioning alarm module and refund you your money and then diagnosis and fix the car.

Smhube00

Is there any way to find out whether the ECU/dme is working properly with out taking to the dealer

Does any body know the sequence for starting

Macster

If the engine runs and doesn't exhibit any symptoms and if the CEL is off this is a good sign the ECU/DME is working ok.

A no start condition with the engine not cranking that can't be traced to a bad battery or battery electrical connector problem or a bad ignition switch is not an ECU/DME problem but one with the security system which doesn't work or doesn't recognize the RFID from the pill in the key head module.

The pill may be bad or the in-dash transceiver bad and not transmitting the signal to trigger a response from the RFID pill or it can't receive the response or somehow the RFID table got corrupted.

Since the engine does not even attemp to start you can't be sure there are not two problems: the security system and the ECU/DME. However, of two based on what you have posted I suspect the seciurity system is suspect.

If you do not want to use a dealer you will just have to call around in your area to auto repair shops that advertise they work on modern Porsches, describe the behavior, and ask if the shop has the proper diagnostics equipment to welll diagnosis the cause of the behavior.

Smhube00

I can lock and un lock wit the key

Security module is brand new and the key is band new too.


I replace the ignition switch this week.

When I turn they, it goes thru the diagnostic , then I Hear a click Sound from engine area.

If I by pass the starter relay in the Back, starter will turn

Macster

By unlock and lock with the key do you mean you can use the lock/unlock buttons? If so this indicates the RF transceiver in the dash works ok and the security system is working at some level.

If you mean you can use the key blade to lock/unlock the car this means really in this context nothing.

If the security module was replaced all keys have to be introduced to the new module. I assume this was done? And that this worked?

Next that click sound from the engine area... that sort of has the sound (no pun) of a bad battery. I recall the car's cabin got wet from rain? This resulted in the security module having to be replaced.

This could have also resulted in a run down battery. It may not have been helped by all the fiddling with no corresponding topping up of the battery so what you are faced with is a low battery.

While the dash lights come on, the gages light up, etc, when you turn the key to on, do they dim even go dark when you turn the key to start?

If so this suggests the no start is due to a low battery.

The starter solenoid requires sufficient power to activate and connect the starter motor pinion gear with the gear on the flywheel. That click click click many report when they try to start an engine with a low battery is the solenoid trying to engage but failing due to insufficient battery power.

The solenoid must fully engage the pinion gear with the flywheel to close a switch and supply power to the starter.

If you are bypassing something you may be forcing the solenoid to fully engage and the starter might then manage to crank the engine, but if the battery power is low there is unsufficient power for the coils to work. IIRC these need around 9 volt so when the power is switched turned off there is sufficient energy generated by the collapsing electrical field to generate a spark.

If this is not present the engine can crank as long as the starter lasts but will not fire and run.

Smhube00

Thanks for you responses

I replaceable the battery (that was the first thing I did )

I can use the key fob buttons to unlock and lock.

Thanks for you response

I replace the battery, that was the first thing I did

Button in the key fob unlock and lock works. Not the key blade

When I by pass the starter unlock relay it turns.

According to wiring diagrams, dme suppose to send a signal to that relay to engage.

What tells the dme to send that signal to starter relay ?

Macster

If I understand your question the security system signals the DME to allow the engine to crank and run.

The security module does this upon sending an RF transmission from an in-dash located transceiver. This RF transmission is picked up by the RFID pill in the key module which turns around and transmits its ID which is received by the security module transceiver, decoded, and the code is looked up in the list of IDs in the security module's non-volatile memory. If the code is found the engine will crank and start as long of course there are no other problems.

The power the RFID pill RF circuitry requires to transmit its ID comes from the energy of the RF transmission sent from the in-dash transceiver

Thus the RFID pill works even if the key lock/unlock feature of the key does not work. They are in fact separate RF/electronic systems at the key module level.

sbelles

Yes, put it in another 02 S.

Macster

That's certainly a way but I'm sure I'd not let someone mess with or I mess with my car's perfectly working DME/ECU to test a suspected bad DME/ECU.

There is the risk of damaging my car's DME or if the other DME is bad damaging the wiring or even a sensor or something else.

Smhube00

So there is a possibility that the in dash transceiver is bad, but the key fob will lock/unlock door and will not start the car ?

Macster

My Boxster wiring diagrams are not here at home so I can't refer to them.

If there were two transceivers in the car, one responsible for servicing the key module RFID pill and another responsible for servicing the key module lock/unlock button RF signals then the one responsible for the key RFID pill signaling could be bad while the other one responsible for the key module lock/unlock signaling is still good.

If there was but on transceiver then it is unlikely it would not work for the RFID pill and yet work for the key lock/unlock RF.