[Heavend]

I've got a v6 156. After about 10 minutes running the speedo dies and brake failure warning lights come on. When cold the speedo works again.
This site suggested that it might be a problem with the ABS module, namely the fets (field effect transistors). I'd like to confirm that a change of the ABS module cured the problem, with an ABS module from the wreckers being cheaper than 3x new fets.

 

[ransoman]

It is the ABS ECU rather than the module itself. Had it on my GTV. Was an easy fix. You will buy the module complete, just unscrew the ECU and swap it over.

 

[gwinter]

Could also be the wire bond from external pin to the internal pad. When it gets hot the connection is severed. If it affects the power or ground pin you will loose access to the ABS ECU. Once it has cooled the contact will be re-established and normal again. In this case you will not find any error code logged.
Repair can only be done with specialist equipment. So easiest to just swap the ECU. The pump itself is normally no problem.