348 Automatic Door Lock Fix - HOWTO

Greetings boys and girls.

Today, let's begin a detailed step-by-step guide on the infamous 348 door locks.
There are couple of common culprits with the door locks that will be addressed here:

1. Door lock key cylinder does not lock/unlock doors (spins freely).

2. Automatic door locks do not work or malfunction (blow fuse, cycle up-down, work intermittently, etc.

So, without further ado, let's begin. A big credit to Ernie for coming out last night and lending a hand with this undertaking.

 

The first issue I needed to solve is that my key lock did not work; the key was spinning freely in the lock. This is caused by a red plastic insert breaking inside the lock (photo below) - it is the part inside the door lock cylinder. Fortunately, there is a nice (albeit pricey) aluminum replacement available through Ricambi made by Hills Engineering.
I suspect that the aluminum insert will NEVER need replacement - it is a quality part.

The way to attack this is to remove the door trim from the inside. NOTE: while taking the strakes improves access somewhat it is NOT necessary and the only reason I took the strakes off is just to see how much access and visibility it gets me. I would also add that taking the strakes off allows you to check the re-assembly of various parts (regulator, latch cable, etc.) for proper routing. It only takes a total of 4 bolts and 2 nuts and maybe 10 mins tops so I would recommend that you do it.
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Remove the door trim by starting with two long strips at the edge of the door: 4 Phillips screws total.
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Remove the trim on the bottom of the door. It is held only with the three clips. Pry gently from the back (slide your hand underneath). It should pop off freely.
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Remove the middle section by prying from behind in same fashion as the bottom piece. As you can see it, it is held with 4 clips.

Do not forget to remove the single phillips screw as shown below!
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Now it is time to remove the upper two pieces (black). There are several screws you need to take out and you also need to loosen the door handle (two 10mm bolts) and the door latch (an allen head).

Carefully withdraw the upper piece from the door and set it aside.
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In this step, we need to remove the final, top trim piece. Again, it is held by various screws. It is pretty self-explanatory, see the photos. You may want to unscrew the door lock plastic plunger.
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Now, we are free to remove the door inner panel. Note, you may also want to remove the strakes at this time (remember two 10mm nuts hidden in the front of the strakes).
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Next, we will disconnect the window and the regulator from the door panel so that we can have a full an unobstructed access to the door lock area:

REMEMBER THAT THE WINDOW MUST BE IN THE DOWN POSITION.

1. Disconnect the window regulator by unscrewing the bolts shown in the prior photo.

2. Push in the retainers for the Window Regulator guide (two red clips) and the door latch cable (black clip). See photos below for detail.

Now you will be able to carefully tilt the door panel away from the door so you can disconnect the various items.

2. Disconnect the cable for the door latch (mark the thread with a sharpie to set the position later), pry on the plastic clip and disconnect the wire.

3. Disconnect the speaker cable.
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Now you will be able to move the door panel away from the door to reveal the glass and the window regulator.

Disconnect the window motor (two spade connectors) (they are protected by by white covers).

Now, you will be able to remove the window by tilting it forward and withdrawing carefully from the car.
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Now we are finally ready to tear in the door lock. If your key is spinning in the lock, most likely the linkage between the door key lock and the actuator is disconnected. Again, this is caused by the red door key lock insert being broken.

The best way to re-assemble the key lock is to remove the key lock assembly. To do that, loosen the 4 10mm bolts that secure the key lock to the door. Then you can remove the entire key assembly from the back and take to the bench to assemble with the new and improved piece by Hill Engineering.
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Now, we can withdraw the door lock assembly, put it on the bench and work on it comfortably.

You can slide the door lock cylinder out. To do that, you must remove the little spring clip (see photos below) that retains the door lock cylinder inside the door lock assembly. Then, you will be able to push the entire door lock cylinder out.

Now, add the little Hills Engineering piece (lubricate it with lithium grease slightly first). Slide back in, and reinstall the little wire clip.
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Now that we have the little aluminum Hills Engineering part re-inserted into the barrel, we can assemble the rest of the door lock and re-install it into the car. There is a spring, metal piece that attached to the electromechanical actuator, and a cir-clip that holds it all together. Note that the spring goes on first, then the gold ball-linkage piece second, and then the cir-clip last.

TIP: PAY ATTENTION and ensure that the ball-end of the metal piece faces towards the back of the car. We have, at first, assembled it incorrectly (the ball linkage facing the front) and had to re-do this step. See photos for detail.

If this was the ONLY problem with your door, you can reconnect the door lock to the electromechanical switch and you are DONE. Test everything several times for a smooth operation and reassemble everything back.

If you are ALSO having issues with the electromechanical lock, continue reading and do NOT attach the door lock to the electromechanical switch at this time.
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Now, my car also had an issue with the automatic lock. The fuse would blow and the operation was intermittent at best. This took the most time to troubleshoot and find a root cause but now having completed over 50 lock and unlock cycles I am pretty confident to say I found the root cause and the implemented solution is a success. So let's keep going.

You need to disconnect the latch cable from the actuator assembly. Then you can undo the black allen head bolts on the side of the door and withdraw the entire lock assembly from the car (of course disconnect the wiring connector).
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In this step you can remove the actuator from the latch assembly and check it for smooth operation. You can connect it back to the harness and cycle the door on/off (remember to "fool" the car that the door is closed by holding the two push switches with your hand) and cycle the locks on/off.

In my case the lock would behave erratically and the fuse would still blow. If that is the case, disconnect the door harness from the car and cycle only the other door. In my case the fuse would STILL blow after few lock/unlock cycles. That lead me to believe that the issue was NOT with the actuator but somewhere else in the system. In the next step I will show you what it was and how we fixed it.
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So, you want to know what was causing my fuse to blow, electric door lock operating intermittently? Was it the actuator? No. Was it the door to body connector? No.
It was.... *drumroll*

It was the relay/ECU that is mounted in the passenger footwell.

As an aside... in typical Italian Ferrari fashion this part is completely unmarked on the diagram.

It is a gray box that has two relays inside (plus associated power electronics). When the door locks, one relay is energized, when it unlocks, the other one sends the current to the actuator. Simple?
But the issue was that one of the relays had a poor connection to the PCB. How do I know that? Cause I spent till 3:00AM hunting with a multimeter and checked EVERY BLOODY trace on that board. Then, I took my trusty soldering iron and touched up EVERY solder joint on that board.
Used copious amounts of CRC contract cleaner to clean the relays.

Then, I held my breath as I plugged everything back and cycled the door locks.

As BORAT would say it. We achieved GREAT SUCCESS!!!
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So, now, it is time to put it back together. Before you do that, you may want to lubricate the door lock mechanism with some lubricant (I used silicone). The re-assembly instructions.

1. Re-install the electromechanical lock. Remember to re-connect the gray latch cable first. On the photo below you can clearly see we forgot to do this, doh!
2. Connect the door cylinder to the electromechanical lock. Use pliers to "pop" the white linkage on to the ball joint. See photo below.
3. Cycle the door to ensure that piece works. Make sure you latch the door when you do that (otherwise the door won't lock). Also you need to again "fool" the car the door is closed by pushing the two push buttons near the wheel wheel.
4. Install the window/regulator. Carefully place the glass by angling it back.
5. Re-install steel the door panel. Make sure the red tubes are routed properly and not kinked. Don't forget to attach the regulator connector and speaker.
6. Make sure that the door goes up/down smoothly and everything is secured properly.
7. Re-install the trim pieces.
8. Get yourself an another cold bier and a pat on the back for a job well-done.

See all the fuses we wasted during the troubleshooting phase. Hopefully you will do much better!
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