407 abs/esp problem

[BX]

Part 1:
The car displayed an esp warning on the dash. It was taken by the owner to a Peugeot dealer who couldn't get his diagnostics to communicate whth tha abs unit. The owner was advised that a new abs unit was required.
Part 2: Miles away from any franchised dealer a handheld diagnostic unit (Autel FR704) was tried and couldn't communicate with the abs unit either. The car was treated to a BSI reset (disconnect the battery etc) and the block connecter on the abs was removed and reseated. The diagnostic unit could then communicate with the ABS/ESP. It displayed the fault code C1301 but did not have a definition for it.

Anyone out there have any ideas

Thanks

[quintet]

It could simply be that the diagnostic tool doesn't understand the fault, rebooting the BSI can lead to an 'undifined' fault when doing diag work using a lexia, have you tried erasing this fault? did it return?

[BX]

Thanks for your reply. The fault (which I since found out is a pressure sensor fault) is permanent and will not clear. Further research indicates 3 possible causes.

1 A faulty pressure sensor in the master cylinder
2 A faulty or maladjusted brake light switch
3 A faulty ABS/ESP ecu, which unfortunately is the most common and most expensive. This problem has afflicted many other marques especially those from a country bordering France (wrong again its NOT Fiat)