New member in need of some help saving a ZT-T Cdti

[SD1too]

Here are some tips for you Marc:

Originally Posted by MGMarc

1) car Windows seem to mist up heavily suggesting water ingress

Now that you've found standing water in the plenum, that could have been responsible.

3) Climate control is sporadically working and only showing FC 00 which I believe means there aren't any faults

The display you mention only relates to the cabin control system. Can you give details of what isn't working?

4) Headlights now seem to be on even when the switch is off

The car may have a special feature enabled which lights the way to your front door.

Originally Posted by MGMarc

In response to a previous post I live in Dorset

Thank you. Could you replace "South" in your profile with "Dorset" then?

Simon

[MGMarc]

Profile edited to now show Dorset

The climate control displays Er where the temperature is supposed to be displayed, when taking the climate system through diagnostics it shows Fc 00 which I believe is no fault found

[SD1too]

Originally Posted by MGMarc

The climate control displays Er where the temperature is supposed to be displayed ...

That apparently denotes a k-bus fault to the BCU Marc.

Simon

[klarzy]

If you have an FBH (fuel burning heater) then disconnect the battery, unplug it and reconnect the battery after 30 mins....

[MGMarc]

It doesn't appear to have a FBH

[klarzy]

Originally Posted by MGMarc

It doesn't appear to have a FBH

and you have already tried a battery reset...?
I would start to look for shorts on the k-bus lines (white / red stripe)??

[MGMarc]

I have no idea how to fault diagnose can bus wiring

Would you be able to give me an idiot's starter guide?

[klarzy]

Originally Posted by MGMarc

I have no idea how to fault diagnose can bus wiring

Would you be able to give me an idiot's starter guide?

The bus (a communications link between all the modules on the car) can be interrupted and cause the type of errors you are finding.
I am no expert, and I am sure someone that is will add to this.... but I would...

Unplug anything on that bus (memory seats, high line stereo, after market hifi, light switch module etc) until either the locks etc started working or I cold measure the voltage to ground in the bus...

[SD1too]

Originally Posted by MGMarc

I have no idea how to fault diagnose can bus wiring
Would you be able to give me an idiot's starter guide?

Not the CAN bus Marc, the K-bus; they are different.

The K-bus is a single wire colour coded white/red/yellow. Fortunately for you, the climate control is at one end of this wire. The next connection is to the 'parking aid' and the one after that is the BCU, so the fault lies somewhere along this route. Phil-T4, a club member who unlike me is an expert on this sort of thing, says that you can use a multimeter to trace K-bus faults. If the bus is active, i.e. working properly, the voltage will be between 1.5 and 2.0 volts below battery voltage. If the bus is idle, it will be at battery voltage. That should give you something to go on!

Simon

[MGMarc]

Are there any K Bus dedicated wiring diagrams?