Fuse 16 - Vertical Acceleration Sensor repair guide
Following my previous post I have received a number of PM's requesting a guide on how I fixed the problem of Fuse 16 so here's my first attempt. As you will appreciate this has been my first real baptism of Maserati ownership and I am sure there will be others who will be able to add improvements in terms of how to remove the lights more easily which I would welcome but this is a guide on how I fixed it.
For a start if you have the workshop manual the problem part is the "Vertical Acceleration Sensor" detailed in the Suspension Sensor chapter pages 9 & 12. Unfortuantely I could not locate any way to disconnect the device remotely to eliminate or confirm this is the cause of teh fuse 16 without getting to the sensor itself.
The sensor location is behind the near (left) side headlight and indicator unit and the only way to get to it is to remove these items:
A) Remove wheel and wheel arch liner in front of wheel (exposing rear of intercooler)
B) Remove grille - 4 screws at the top and with slight leverage pull the bottom away from clips
C) Remove Air filter cover and filter
D) Headlamp - disconnect connector. The headlamp is held in by three nuts. The easiest to remove is at the back of the lamp. The next you can get to following removal of air filter from engine bay. The third one is a pig towards the front of the headlamp and is underneath. I did this with aid of a torch and 10mm ratchet spanner working from the side of the lamp and via the grille opening. The headlamp unit then slides forward out of car but you might need to consider protecting paintwork with tape.
E) Sidelight/indicator unit - again disconnect connectors and undo nut at back of unit onto plastic bracket. There is a second nut is underneath the unit which is again tricky to get to and you have to undo working blind with 10mm ratchet spanner.
Hopefully the sensor is now accessible as photo below indicates (with yellow label):
F) I tried undoing the sensor directly from bracket but this started to distort so I would recomend disconnecting connector from sensor (small retaining clip) and undo the bracket from bodywork. It was at this point you will hear the tell tale rattle to confirm you have identified the source of your fuse 16 problems
G) Working at a bench I then removed sensor from bracket.
H) I would then strongly recomend marking lid with base of sensor as it can be fitted 2 ways and you will want to get it correct when you refit. Then with small screwdriver you will need to clean sealant from screwheads retaining lid. Once lid removed you will find a loose block of metal (brass?) which has been shorting out connectors within sensor.
I) Having cleaned out sensor of dust and small areas of corrosion, I then used small screwdriver to clean off old grey glue and then re- araldited metal block back onto base. There is an outline on base to position it. I actually cut a piece of insulating tape lengthways and fixed to top of block to help position and then retain in position until glue set (I used rapid set araldite which took about 10 minutes). I also used some clear mastic to ensure good seal around joint and screws. The photo below shows block back in position.
J) Reinstallation is just a reverse of processes above.I fitted another fuse before re-assembly just to check. Fitting the two awkward nuts on the two lights is the most awkward trying to position from above. I would also suggest you check that you have fitted all connectors correctly to the lights before fitting wheel arch liner as I discovered the following night that I have forgotten one on the side light.
K) Anyway the good news is that once refitted all the airbag warning lighst and suspension "ERROR" light no longer showing on dash. Test drive last night and all systems seem to be functioning as normal.
Good luck if you having a go at thsi yourself - it took me about 3 hours but then I was on a steep learning curve. For the price of some glue, mastic and scraped knuckles I think I may have saved over £600 for a new sensor plus labour.
