BCU error codes alarm CDL

[zaph]

I have managed to get TOAF to play nice with the car and got the following errors from the BCU:

Alarm trigger:Main CDL Switch (unlock)

Alarm mislock-CDL overuse

both Sporadic errors.

Does anybody know what these errors refer to?

[SD1too]

Originally Posted by zaph

Alarm trigger:Main CDL Switch (unlock)

The main central door locking switch is the oval switch residing on the lower centre console between the seats.

Originally Posted by zaph

Alarm mislock-CDL overuse

The BCU monitors the CDL master switch and allows a limited number of operations over a predetermined period of time. If this is exceeded the door latch motors are disabled to prevent overheating. The doors are always disabled in the unlocked position and the alarm will "blip" to inform the driver of a mislock. Normal operation is restored after a cooling period has elapsed. [Source: RAVE]

Any help?

Simon

[zaph]

That is helpful and scans with what I suspected. The first fault was the centre console switch not keeping the doors shut.

I have replaced the switch with a known good switch from another 75.

So the way I see it, the problem is either a short in the wiring to the switch or the BCU itself has gone bad. Triggering the alarm.

[Raven Black]

Reading posts like this just shows the sheer enormity of things that can go wrong with these cars with the huge amount of electronics and sensors required. It does make me wonder how the owners who live abroad or in areas with no access to people with t4s and the necessary expertise manage to keep them going.
It is why, after battling for 7 years with my range rover v8 02 model I gave up, only to find after all I needed was an expert with a t4 which I had no idea about.
Even stranger, when I lived in the USA we had lots of cars with electric seats, airbags. Windows. Auto dim lights ect and they never went wrong on mid 70's cars like the Cadillac Eldorado and Lincoln Town car, 75 and 78, chev el Camino, driven many thousands of miles and all ok. They must have been made better and t4s didn't exist then, so I am puzzled about this.
Ps I have brand new brakes all round fitted early this year, but just this week when Starting the car I get brake failure coming up on the IPK. Another anomaly. They are perfectly fine.

[SD1too]

Originally Posted by zaph

So the way I see it, the problem is either a short in the wiring to the switch or the BCU itself has gone bad. Triggering the alarm.

Hi Mark,

From your previous thread ...

Originally Posted by vitesse

You’ve got BigRuss in Liversedge, not only does he have a T4 but more important knows these cars very well.

Have you contacted Russ yet? Your fault is classic material for assistance from T4.

Simon

[zaph]

Originally Posted by SD1too

Hi Mark,

From your previous thread ...

Have you contacted Russ yet? Your fault is classic material for assistance from T4.

Simon

I haven't had time with work and now I have TOAF working now, so I would prefer to try and fix the problem myself first.

If it is a relatively simple fault like a shorted wire or broken switch, there is no point spending time and money on an unnecessary diagnosis.

When it comes to cars I like to be as self reliant as possible.

If it defeats me I will get a professional after the Christmas holidays.

[zaph]

As for my progress, I have cleared all the errors on the bcu and reconnected the battery.

That way, next time the alarm is triggered, I will know exactly what triggered it.

[zaph]

Thought I would update this because I hate threads that go dark without the solution.

I seemed to have fixed the issue, the problem was the console centre switch. My initial replacement of the switch from another 75 didn't work because the mark 2 uses a different switch.

The older, better, switch has a toggle for lock and unlock. The newer one is just a single action switch which simply unlocks or locks based on the current locking state.

My car didn't like the older switch but a new replacement mark 2 switch cured the problem. The alarm is behaving itself.

[SD1too]

Originally Posted by zaph

The older, better, switch has a toggle for lock and unlock. The newer one is just a single action switch which simply unlocks or locks based on the current locking state.

Thanks for posting the solution Mark.

So you're saying that your 2005 car doesn't have a three position rocker switch but a simple non-latching "push to make" switch?

Simon

[zaph]

Originally Posted by SD1too

Thanks for posting the solution Mark.

So you're saying that your 2005 car doesn't have a three position rocker switch but a simple non-latching "push to make" switch?

Simon

Yes, probably a project drive cutback.

It seems if you fit the wrong version, the alarm and central locking system can have a bit of a meltdown.