door lock, alarm problems

[Heavydee]

I have a 1999 Boxster, 5spd manual, fully adjustable power seats. The central locking system is giving me problems.

I removed the ECU from under the seat, removed the board, soaked it in 99% medical grade alcohol for several hours. I then drained it and dried it thoroughly. I also changed the ignition switch.

Everything works, including the window drop, windows, interior lights. Car starts and runs without a problem. The only thing that still doesn't work is the locking/alarm system. I get what sounds like a buzzing, grinding sound coming from the control module under the seat, and then the double beep from the horn. I still have the following codes:

25
60
34
46
47
61
58

I called the local dealer, and they told me that it is usually an all or nothing response from the ECU, and that it is very strange that everything works except for the door locks.

Before I spend the money for a new ECU and having it programmed, is there anything else that I can check or replace? Thanks for your help.

Rob

[JFP in PA]

As several of these DTC codes point to the central locking system (46, 47, 34) I would say that it points to the central locking/alarm/immobilizer control box under the seat, not the car's central computer (which is called a DME). Several codes also note locking positions not being reached (61), which ties into the car beeping.  So, you may have a combination of one of the doors not reaching locked position. and/or a bad central locking control unit.

[Loren]

I suggest you clear the codes - operate the doors and locks again - and see what codes you get then.

[JFP in PA]

4 minutes ago, Loren said:

I suggest you clear the codes - operate the doors and locks again - and see what codes you get then.

Good thought!

[Heavydee]

Hi --

Thanks for your responses.

I cleared the codes and tried to use the key fob to lock the car. It came back with only one code:

 

60

which I find very surprising. I did this twice, and got the same code. I still get the grinding/buzzing sound from the immobilizer unit, and the two beeps, and the doors do not lock. Is there anything else that I can try, or is my unit shot?

 

Is there a way to test the unit itself?

 

Thanks,

Rob

[Loren]

Fault 60 - Central locking limit position - Locked not reached

 

Most likely a mechanical failure in the door locking mechanism (in the door that does not lock).

You can also listen for audible click when you lock the door - try using the key to lock.

Do a search here for door lock repairs.

[Heavydee]

Loren --

 

When I use the key to lock, I get the two buzzing sounds and two horn beeps. The driver's door locks, but the passenger door does bot. When I unlock it, I get just the one buzzing sound.

 

Yesterday, I took the driver's lock mechanism out of the door, but did not disconnect any of the wires. I manipulated it a bit, but still got the same reactions from the car when I tried to lock it with the fob. the dash button did nothing at all. I reset the spring clip on the locking mechanism, and put it back in the car. This resulted in the reduction of the codes down to just code 60.

 

There is no question that a previous owner or mechanic had been in the doors before me, as the inner door plates are missing, along with some of the clips. If I were to do the same thing with the passenger side that I did yesterday with the driver's side, do you think that this could fix the problem?

 

I am troubled with the fact that the gas flap does not lock either.

 

Thanks for your help.

 

Rob

[Loren]

19 minutes ago, Loren said:

Fault 60 - Central locking limit position - Locked not reached

 

Most likely a mechanical failure in the door locking mechanism (in the door that does not lock).

You can also listen for audible click when you lock the door - try using the key to lock.

Do a search here for door lock repairs.

 

Possible cause of fault
• Central locking switch faulty
• Short circuit to ground/open circuit in wiring between the alarm system control module, central locking switch or door locks
• Driver's/passenger's door lock faulty
• Control module faulty

[Loren]

1 minute ago, Heavydee said:

I am troubled with the fact that the gas flap does not lock either.

 

Check to see if the lock pin is broken off.

If so, I did a DIY on how to replace that here:

 

[Heavydee]

The pin for the gas flap actuator is intact.

 

By "central locking switch", you are referring to the switch on the dash, correct?

[Loren]

Yes on central locking switch.

But historically these are usually mechanical failures in the door lock.

 

If the gas lock in is intact is the receiver in the gas lid there?

[Heavydee]

Yes, the receiver is there. I never hear a clicking sound. the only sounds I get are the buzzing from the area of the immobilizer and the two horn beeps. Can you give me an idea of what the buzzing sound is?

[Loren]

Two beeps mean that there is more than one zone open or that the controller has failed.

I would go after the door lock first.

 

BTW... the immobilizer/alarm box did not get wet through plugged top drains or other?

If it did get wet then you will need a new or rebuilt one as water damage will lead to future failures as thing corrode. 

 

[Heavydee]

Thanks for all of your help, Loren. I think that the water damage happened with the previous owner when the car was left outside with a torn rear window. I will try to manipulate the passenger side door lock to see if that makes a difference. Fingers crossed, as I do not want to spend the money right now to replace the immobilizer.