Weird locking/unlocking issues

[ripratama]

Hello everyone,

Having read through similar threads and tried the solutions without success, I'm hoping someone can direct me to the exact problem and solution to my problem.

Car is 2003 tiptronic Boxster, RHD.

Initially only the remote locking/unlocking from keyfob wouldn't work. Inserting key into driver's handle would lock/unlock both doors just fine. Button on dash also worked, and so did the frunk and trunk switches. So I thought only new key fob would be needed (battery checked ok and microswitches worked fine and lit up).

Brought it to the dealer, they used PIWIS to scan codes and to my surprise upon collecting the car, they seemed to have caused more problems:

Would not work:
- central locking/unlocking from door handle
- front trunk switch
- rear trunk switch
- interior light
- trunk light

Would work, but only when key is not yet removed from ignition:
- locking/unlocking via dashboard button
- passenger door's unlocking from driver's handle using 2nd key, but not locking
- rear trunk switch
- interior light
- trunk light

Completely lost:
- front trunk access
- locking of passenger's door from driver's handle

I still retain:
- normal ignition/start of engine
- dropping of windows when opening the doors


So it seems the car only senses open doors when current is still supplied i.e. Key is not yet removed. When it is removed then I'd lose all functionality of locks and interior lighting.

Dealership quoted about USD 2,300 in parts (control unit, fob, both door locks, frunk actuator, passenger actuator). Will that be my only way out? They denied responsibility even though most functions had been tested ok when they received the car initially. I would bite the bullet if the car had experienced the problems before coming the dealer, but not this way.

Wish I hadn't gone to the dealer and just persevere happily with faulty fob.

[78F350]

The box under the left side seat is the 'central locking unit' The antenna wire for the remote may not be connected securely.
Check this post and the thread it was posted in. The round gold colored connector is where the antenna connects if you have a 3 button remote.

***Note: Do not put your key in the ignition with the seat removed. It can cause an airbag fault.***

Originally Posted by Qmulus

Well, I just so happen to have an M535 996.618.262.03 module right next to me. From what I have seen, the cars with three button remotes and the M535 module have the coax connection. The cars with two button remote and M531 module have the coax run through terminals the blue connector. Either way, you have the coax antenna in the harness, but on the M535 they split it out and put it through a proper RF connector. So, I would say that you have an M531 alarm/immobilizer module in your car.

A picture is worth a thousand words, so here you go.

[ripratama]

Originally Posted by 78F350

The box under the left side seat is the 'central locking unit' The antenna wire for the remote may not be connected securely.

Thanks; checked the coaxial plug and connection is intact. Problems still persist, however.

[thom4782]

Bit of a left field guess here, but when so many electrical problem occur at once perhaps its the ignition switch that's gone bad.

What codes did the dealer find?

[ripratama]

Originally Posted by thom4782

Bit of a left field guess here, but when so many electrical problem occur at once perhaps its the ignition switch that's gone bad.

What codes did the dealer find?

Dealer only gave me a quote of the parts with P/Ns but not the codes.

Further investigation and findings:

Upon re-checking the 535 module under the seat, the fuse was found defective and replaced with new one.

Everything then went back normal (hoorah!) for few seconds, then it blew again (boo!).

After wasting 3 new fuses which immediately blew upon insertion, I gave up. Could it be:
1. Pinched/split open wire?
2. Faulty actuator(s)?
3. Faulty 535 module?

Would appreciate anyone's advice to pin point the exact cause.

[geetee]

Originally Posted by thom4782

Bit of a left field guess here, but when so many electrical problem occur at once perhaps its the ignition switch that's gone bad.

What codes did the dealer find?

You'd be amazed at what this stupid little thing can do when there's an issue.
The ign switch is cheap with some hours of labor from you...and can cause similar issues you have and a new one can solve. As much as I hate throwing parts at an issue It's cheap to do...and do fail quite often

[Anker]

Get a wiring diagram and a multimeter and start looking for a short to the frame.

[tonycarreon]

Originally Posted by geetee

You'd be amazed at what this stupid little thing can do when there's an issue.

+upvote

"my left brake makes a weird noise when i turn right"
"check the ignition switch..."