Intermittant faults, water ingress?

[Chipmunk]

I have a 2.7 diesel S type automatic which is displaying intermittent faults ranging from a simple non start, ie turn the key and absolutely nothing happens, to various erroneous warning lights and messages when the car does decide to start! including Gearbox, parking brake and DSC faults, sometimes the power steering will pack up, sometimes the gearbox will not change up, sometimes the tacho or speedo will not work, sometimes one not the other will .

My engineers have inspected and run diagnostics to no avail, once the car does start, the fault indications and gearbox/power steering malfunctions, do fade away, when the engine has run for a while and stopped and restarted.

I suspect water in the electrics somewhere, but has anyone any ideas where? Anyone any ideas?

[Gazbo]

maybe check in the boot area.its a known area where water leaks into the spare wheel bay.quite a lot of electrical boxes on the right hand side (looking into the boot)behind the carpets

[Guest]

Hi Andy and Welcome to the Club,

Has your battery been thoroughly examined and the alternator checked? The S Type Control Systems can throw major wobblies if the battery fails. If you're convinced it's water ingress check the wheel/battery well for damp - water can get in around the boot and/or light clusters and also check the connections to the major systems control modules in the engine bay for damp and or poor/corroded connections.

Hope this helps and please keep us posted.

Cheers,

Steve

[Chipmunk]

thanks guys, already checked the boot area, dry as a bone, is there a control module which is common, ie can affect all the systems mentioned?

[Chipmunk]

Yep and the battery and alternator have been checked, all ok.

[Guest]

Hi Andy,

The S Type has a number of control modules for different aspects of the vehicle. Setting aside those concerned with say audio, navigation, parking sensors, et al there are the important ones associated with key aspects of the car and its performance. At the core of these in the ECM which is connected via a CAN Bus (a pair of cables which carry signals from all connected modules) to the other key modules such as ABS, TCS, etc. and the Instrument Cluster; see page 147 in the attached document for details.

To do anything sensible with these beyond simply checking that all cabling is fully connected, free from corrosion, damage, etc. you will need a suitable ODBC Code Reader to help you list and examine the Diagnostic Trouble Codes (DTCs) reported by the various modules and from those to identify the underlying problems. You will also need the ODBC Code Reader to re-set the DTC's after you have fixed the underlying problems.

Hope this helps and keep us posted.

Cheers,

Steve

 

S Type Wiring.pdf